Ziatech Corporation | ZT 89CT04 | Specifications | Ziatech Corporation ZT 89CT04 Specifications

ZT 8832
I/O Control Processor
OPERATING MANUAL
For ZT 8832 Revision 0.5
and ZT 88CT32 Revision 0.4
Reorder Part Number ZT M8832
May 10, 1994
1050 Southwood Drive
San Luis Obispo, CA 93401 USA
FAX (805) 541-5088
Telephone (805) 541-0488
ZIATECH 5+5 WARRANTY
For Ziatech Board- and System-Level Computer Products
FIVE-YEAR LIMITED WARRANTY
Products manufactured by Ziatech Corporation are covered from the date of
purchase by a five-year warranty against defects in materials, workmanship,
and published specifications applicable to the date of manufacture. During
the warranty period, Ziatech will repair or replace, solely at its option,
defective units provided they are returned at customer expense to an
authorized Ziatech repair facility. Products which have been subjected to
misuse, abuse, neglect, alteration, or unauthorized repair, determined at the
sole discretion of Ziatech, whether by accident or otherwise, are excluded
from warranty. The warranty on fans and disk drives is limited to two years
and the warranty on flat panel displays is limited to nine months from date
of purchase. Other products and accessories not manufactured by Ziatech
are limited to the warranty provided by the original manufacturer.
Consumable items (fuses, batteries, etc.) and software are not covered by
this warranty. Within 90 days of shipping date, Ziatech will replace software
disk media should it prove defective.
Ziatech may offer, where applicable and available, replacement products;
otherwise, repairs requiring components, assemblies, and other purchased
materials may be limited by market availability.
Ziatech assumes no liability resulting from changes to government
regulations affecting use of materials, equipment, safety, and methods of
repair. Ziatech may, at its discretion, offer replacement products.
THE ABOVE WARRANTY IS IN LIEU OF ANY OTHER WARRANTY,
WHETHER EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING,
BUT NOT LIMITED TO, ANY WARRANTY FOR FITNESS OF
PURPOSE, MERCHANTABILITY, OR FREEDOM FROM INFRINGEMENT OR THE LIKE, AND ANY WARRANTY OTHERWISE ARISING
OUT OF ANY PROPOSAL, SPECIFICATIONS, OR SAMPLE.
Ziatech neither assumes nor authorizes any person to assume for it any other
liability. The liability of Ziatech under this warranty agreement is limited to
a refund of the purchase price. In no event shall Ziatech be liable for loss of
profits, use, incidental, consequential, or other damage, under this
agreement.
SPECIAL EXTENDED WARRANTY OPTION
In addition to the standard five-year warranty, Ziatech offers, for a
nominal fee, an extended period of warranty up to five extra years.
This extended warranty period provides similar coverage and
conditions as stated above in the five-year limited warranty
agreement.
LIFE SUPPORT POLICY
Ziatech products are not authorized for use as critical components in
life support devices or systems without the express written approval
of the president of Ziatech Corporation. As used herein:
1.
Life support devices or systems are devices or systems which
support or sustain life, and whose failure to perform, when
properly used in accordance with instructions for use provided in
the labeling, can be reasonably expected to result in a significant
injury to the user.
2.
A critical component is any component of a life support device
or system whose failure to perform can be expected to cause the
failure of the life support device or system, affect its safety, or
limit its effectiveness.
1998 Ziatech Corporation
Turbo Debugger is a registered trademark of Borland International, Inc.
IBM PC/XT/AT and PC DOS are registered trademarks of International
Business Machines, Inc.
MULTIMODULE is a trademark of Intel Corporation.
DEBUG/RT is a trademark of Paradigm Systems.
CUSTOMER SUPPORT
If you have a technical question, please call Ziatech’s
Customer Support Service at the following number:
Corporate Headquarters: (805) 541-0488
(805) 541-5088 (FAX)
You can also use a modem to leave a message on the 24-hour
Ziatech Bulletin Board Service (BBS) by calling
(805) 541-8218. The BBS will also provide you with current
Ziatech product revision and upgrade information.
If you have a sales question, please contact your local Ziatech
Sales Representative.
PREFACE
This manual describes the operation and use of the ZT 8832 and the
ZT 88CT32. The boards are functionally identical. However, the
ZT 88CT32 consumes less power and operates over a wider
temperature range. Refer to Appendix B for actual specifications. The
term ZT 8832 is used throughout the manual to reference both
products, except where otherwise noted.
The following organizational outline describes the focus of each
chapter in this manual. Section headings enclosed in boxes indicate
the locations of labeled tabs for quick access to the appropriate
information.
I.
INTRODUCTION
Chapter 1, "Introduction," offers an overview of the ZT 8832. It
includes a product definition, a list of product features, a functional
block diagram, and a brief description of each block. This chapter is
most useful to those comparing the features of the ZT 8832 against
the needs of a specific application.
II.
GETTING STARTED
Chapter 2, "Getting Started," summarizes the information essential
to getting your ZT 8832 operational. This includes system
requirements, memory and I/O mapping, and a brief description of the
jumper options. In many cases this information is all that is needed to
begin using the ZT 8832.
The section entitled "USER’S
REFERENCE" includes more detailed discussions of the topics
presented in this chapter.
Preface
III.
USER’S REFERENCE
Chapter 3, "Theory Of Operation," presents a detailed description
of ZT 8832 system level operation. Topics discussed include
commonly asked questions, memory and I/O organization, and
interrupt structure.
Chapter 4, "Application Examples," gives specific examples of the
ZT 8832 in operation, including code to implement these applications.
Chapter 5, "Processor Description (V40)," divides the V40 into
functional blocks and presents a theory of operation for each. This
chapter is most useful to those not familiar with the architecture of the
V40/8088 series microprocessor.
Chapter 6, "Processor Configuration (V40)," describes the
architecture of a V40 software programmable register set used to
configure peripherals resident on the V40 for specific applications.
These peripherals are described in detail in the following chapters.
Chapter 7, "Counter/Timers (V40)," describes the function,
configuration, and operation of the V40 Counter/Timer Control Unit,
which includes three 16-bit counter/timers and is functionally
equivalent to the 8254 Programmable Interval Timer. The chapter
also includes register descriptions.
Chapter 8, "Interrupt Controller (V40)," describes the function,
configuration, and operation of the V40 Interrupt Control Unit, a programmable interface between interrupt-generating peripherals and the
CPU. The chapter also includes register descriptions.
Preface
Chapter 9, "DMA Controller (V40)," describes the function,
configuration, and operation of the V40 Direct Memory Access
Control Unit, a programmable peripheral device used to direct high
speed data transfers between the ZT 8832 and SBX expansion module
I/O. The chapter also includes register descriptions.
Chapter 10, "Serial Communications (V40)," describes the function, configuration, and operation of the V40 Serial Control Unit, a
single serial channel that performs asynchronous serial
communication between the V40 and a serial device external to the
ZT 8832. The chapter also includes register descriptions.
Chapter 11, "Serial Communications (82050)," describes the
function, configuration, and operation of the serial controller external
to the V40. This is the Intel 82050 Asynchronous Communications
Controller, or equivalent. The chapter also includes register
descriptions.
Chapter 12, "Parallel I/O," describes the function, configuration,
and operation of the ZT 8832 parallel I/O. Parallel I/O is used to
control industry standard I/O modules, such as those manufactured by
Opto 22, Gordos, Crydom, and Adtek. The on-board programmable
LEDs are also controlled through parallel I/O.
Chapter 13, "Watchdog Timer," describes the function, configuration, and operation of the ZT 8832 two-stage watchdog timer,
which is used to monitor ZT 8832 operation and take corrective action
if the ZT 8832 fails to function as programmed.
Chapter 14, "SBX Expansion Module," contains a description and
installation information for the optional SBX expansion module,
which can be used to expand the I/O capabilities of the ZT 8832.
Preface
Chapter 15, "Numeric Data Processor (8087)," explains
installation and operation of the optional 8087 Numeric Data
Processor, used to enhance the math capabilities of the ZT 8832 for
numerically intensive applications.
IV.
APPENDICES
Appendix A, "Jumper Selections," provides a detailed explanation
of the ZT 8832 options that are selectable through jumper configuration or the use of cuttable traces.
Appendix B,
"Specifications," contains the electrical,
environmental, and mechanical specifications for the ZT 8832.
Frontplane connector pinouts, cable drawings, and timing diagrams
are also included.
Appendix C, "Customer Support," offers a product revision
history, technical support information, and instructions for returning
the ZT 8832 for service.
Appendix D, "Glossary," defines important terms and acronyms
used throughout the manual.
CONTENTS
I.
INTRODUCTION
Chapter 1. INTRODUCTION
1-1
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Product Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Features of the ZT 8832 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Development Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
FUNCTIONAL BLOCKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
V40 (µPD70208) Processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Local Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Dual Port Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
Board Select Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
Serial Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
Parallel Input/Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
Interrupt Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Counter/Timers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Watchdog Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
zSBX Expansion Module Socket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
Numeric Data Processor Socket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
II.
GETTING STARTED
Chapter 2. GETTING STARTED
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
UNPACKING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WHAT’S IN THE BOX? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SYSTEM REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ZT 8832 Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-1
2-1
2-2
2-2
2-3
2-3
Contents
ZT 88CT32 Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
INSTALLING THE ZT 8832 WITH STD ROM . . . . . . . . . . . . . . . . . . . . . 2-5
Memory Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Cable Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Jumper Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
INSTALLING THE ZT 8832 WITH DOS MPX . . . . . . . . . . . . . . . . . . . . . 2-7
Memory Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Cable Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Jumper Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
MEMORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10
I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
JUMPER OPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14
III. USER’S REFERENCE
Chapter 3. THEORY OF OPERATION
3-1
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
COMMONLY ASKED QUESTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
DUAL PORT MEMORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
STD BUS AND LOCAL CONTROL PORTS . . . . . . . . . . . . . . . . . . . . . . . 3-9
STD Bus Control Port Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
STD Bus Control Port Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
Local Control Port Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
Local Control Port Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13
BOARD SELECT OPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
STD BUS INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17
RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21
Chapter 4. APPLICATION EXAMPLES
4-1
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
EXAMPLE 1: V40 INITIALIZATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Program Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
EXAMPLE 2: PERIPHERAL INITIALIZATION . . . . . . . . . . . . . . . . . . . . 4-6
Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
Program Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
EXAMPLE 3: WATCHDOG TIMER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Contents
Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Program Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19
Chapter 5. PROCESSOR DESCRIPTION (V40)
5-1
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
ZT 8832 SPECIFICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
COMMONLY ASKED QUESTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
FUNCTIONAL BLOCKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
CPU - Central Processing Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
BIU - Bus Interface Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19
BAU - Bus Arbitration Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19
CGU - Clock Generator Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20
VCR - V40 Configuration Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20
WCU - Wait Control Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21
SCU - Serial Control Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21
TCU - Counter/Timer Control Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21
ICU - Interrupt Control Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
DCU - DMA Control Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23
MEMORY AND I/O ADDRESSING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-24
INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-27
Divide Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-31
Single-Step . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-31
Non-Maskable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-32
Fixed Vector Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-32
Overflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-32
Check Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-33
Variable Vector Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-33
Emulation Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-33
8080 EMULATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-34
Chapter 6. PROCESSOR CONFIGURATION (V40)
6-1
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
VCR - V40 CONFIGURATION REGISTERS . . . . . . . . . . . . . . . . . . . . . . . 6-2
OPCN - On Chip Peripheral Connection Register . . . . . . . . . . . . . . . . 6-3
OPSEL - On Chip Peripheral Selection Register . . . . . . . . . . . . . . . . . 6-4
OPHA, DULA, IULA, TULA, and SULA . . . . . . . . . . . . . . . . . . . . . . . 6-5
WCY2 - Wait Cycle 2 Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
WCY1 - Wait Cycle 1 Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
WMB - Wait Memory Boundary Register . . . . . . . . . . . . . . . . . . . . . . . 6-9
RFC - Refresh Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10
Contents
TCKS - Counter/Timer Clock Selection Register . . . . . . . . . . . . . . . . 6-10
RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12
Chapter 7. COUNTER/TIMERS (V40)
7-1
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
ZT 8832 SPECIFICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
Read/Write Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
Mode Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5
Clock Select and Divisor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5
Counter/Timers 0, 1, and 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5
PROGRAMMABLE REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7
Timer Mode Register (TMD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8
Count Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12
Status Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14
Count Latch Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14
Multiple Latch Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-15
Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-16
Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-28
Chapter 8. INTERRUPT CONTROLLER (V40)
8-1
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2
ZT 8832 SPECIFICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3
FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
Interrupt Request Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
Interrupt Mask Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
Priority Resolver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
Interrupt In-Service Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
Control Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6
Read/Write Control Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6
Initialization and Operation Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6
PROGRAMMABLE REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-7
Initialization Words (IIW1, IIW2, IIW3, and IIW4) . . . . . . . . . . . . . . . 8-8
Operation Words (IMKW, IPFW, and IMDW) . . . . . . . . . . . . . . . . . . 8-12
Status Words (IRQ, IIS, and IPOL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-16
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-19
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-19
Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-19
Interrupt Vectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-21
Contents
Interrupt Nesting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Level- or Edge-Triggered . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Finish Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic Priority Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specific Priority Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interrupt Masking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interrupt Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8-22
8-25
8-26
8-28
8-29
8-30
8-31
8-31
Chapter 9. DMA CONTROLLER (V40)
9-1
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-2
ZT 8832 SPECIFICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3
FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-4
Internal Bus Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5
Address Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5
Address Adjuster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5
Count Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-6
Count Adjuster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-6
Control Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-6
PROGRAMMABLE REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-7
DMA Initialize Command (DICM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-8
DMA Channel (DCH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-8
DMA Base Count/Current Count (DBC/DCC) . . . . . . . . . . . . . . . . . . 9-10
DMA Base Address/Current Address (DBA/DCA) . . . . . . . . . . . . . . 9-11
DMA Device Control (DDC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-12
DMA Mode (DMD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-13
DMA Status (DST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-15
DMA Mask (DMK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-16
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-17
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-17
Autoinitialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-18
Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-18
Chapter 10. SERIAL COMMUNICATIONS (V40)
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ZT 8832 SPECIFICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Read/Write Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interrupt Generation Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10-1
10-2
10-2
10-3
10-4
10-4
10-4
10-4
Contents
PROGRAMMABLE REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5
Serial Status Register (SST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-6
Serial Command Register (SCM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-8
Serial Mode Register (SMD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-9
Serial Interrupt Mask Register (SIMK) . . . . . . . . . . . . . . . . . . . . . . . 10-10
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-11
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-11
Serial Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-12
Baud Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-13
Interrupt and Polled Communication . . . . . . . . . . . . . . . . . . . . . . . . . 10-15
Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-16
Chapter 11. SERIAL COMMUNICATIONS (82050)
11-1
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-2
ZT 8832 SPECIFICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-3
FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4
Read/Write Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-5
Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-5
Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-5
Modem Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-6
Interrupt Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-6
PROGRAMMABLE REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-7
Transmit and Receive Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-8
Line Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-8
Line Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-11
Modem Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-13
Modem Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-15
Divisor Latch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-17
Interrupt Identify . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-18
Interrupt Enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-19
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-20
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-20
Serial Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-21
Baud Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-22
Interrupt and Polled Communication . . . . . . . . . . . . . . . . . . . . . . . . . . 11-23
RS-485 Serial Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-23
Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-24
Contents
Chapter 12. PARALLEL I/O
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ZT 8832 SPECIFICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output Latch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PROGRAMMABLE REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Programming the Parallel Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Programming the Light Emitting Diode . . . . . . . . . . . . . . . . . . . . . . . .
Mixing I/O in a Single Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12-1
12-1
12-2
12-3
12-3
12-4
12-4
12-5
12-6
12-6
12-6
12-7
12-7
Chapter 13. WATCHDOG TIMER
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ZT 8832 SPECIFICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 1 Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 1 Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Multiple Stages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing Time Delays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13-1
13-2
13-2
13-3
13-3
13-4
13-4
13-4
13-5
13-5
13-6
13-7
13-8
Chapter 14. SBX EXPANSION MODULE
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ZT 8832 SPECIFICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14-1
14-2
14-3
14-4
14-5
Chapter 15. NUMERIC DATA PROCESSOR (8087)
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ZT 8832 SPECIFICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Coprocessor Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Error Handling and Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15-1
15-2
15-2
15-3
15-4
15-4
15-6
Contents
Further Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-7
IV. APPENDICES
Appendix A. JUMPER CONFIGURATIONS
A-1
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
JUMPER OPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
CUTTABLE TRACES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-16
Appendix B. SPECIFICATIONS
B-1
ELECTRICAL AND ENVIRONMENTAL . . . . . . . . . . . . . . . . . . . . . . . . . B-2
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
DC Operating Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
Battery Backup Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
STD Bus Loading Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-3
MECHANICAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-6
Card Dimensions & Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-6
Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-7
Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-17
TIMING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-22
Appendix C. CUSTOMER SUPPORT
C-1
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
REVISION HISTORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ZT 8832 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ZT 88CT32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TECHNICAL ASSISTANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RELIABILITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RETURNING FOR SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ZIATECH 5+5 WARRANTY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C-1
C-2
C-2
C-3
C-4
C-5
C-6
C-7
Appendix D. GLOSSARY
D-1
Contents
V.
INDEX
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i
TABLES
Table 2–1
Table 2–2
Table 3–1
Table 5–1
Table 5–2
Table 5–3
Table 5–4
Table 5–5
Table 5–6
Table 6–1
Table 6–2
Table 6–3
Table 7–1
Table 8–1
Table 8–2
Table 9–1
Table 9–2
Table 10–1
Table 10–2
Table 10–3
Table 11–1
Table 11–2
Table 11–3
Table 11–4
Table 11–5
Table 12–1
Table 13–1
Table A–1
Table A–2
Table A–3
Table A–4
Table B–1
Table B–2
STD ROM Jumper Configuration. . . . . . . . . . . . . . . . . . . . . . 2-6
DOS MPX Jumper Configuration. . . . . . . . . . . . . . . . . . . . . . 2-8
Devices Affected by Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23
Segment Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9
Implied Use of General Registers. . . . . . . . . . . . . . . . . . . . . 5-11
CPU Reset State. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23
Interrupt Sources. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28
Interrupt Vector Table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30
Emulation Mode Registers and Flags. . . . . . . . . . . . . . . . . 5-36
V40 Configuration Registers. . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
STD ROM Programmable Address Selection. . . . . . . . . . . 6-6
V40 Configuration Register Defaults. . . . . . . . . . . . . . . . . . 6-12
TCU Register Addressing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7
Interrupt Controller Inputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3
ICU Register Addressing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-7
DCU Register Addressing. . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-7
DCU Register Default State. . . . . . . . . . . . . . . . . . . . . . . . . . 9-17
SCU Register Addressing. . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5
SCU Register Defaults. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-11
ZT 8832 Baud Rate Counts. . . . . . . . . . . . . . . . . . . . . . . . . 10-14
ACC Register Addressing. . . . . . . . . . . . . . . . . . . . . . . . . . . 11-7
Serial Character Length. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-8
ACC Register Defaults. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-20
ACC Baud Rate Divisors. . . . . . . . . . . . . . . . . . . . . . . . . . . 11-22
ACC Register Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-25
Parallel I/O Register Addressing. . . . . . . . . . . . . . . . . . . . . 12-5
Watchdog Timer Stage Delays. . . . . . . . . . . . . . . . . . . . . . . 13-7
Jumper Cross Reference. . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
ZT 8832 Jumper Descriptions. . . . . . . . . . . . . . . . . . . . . . . . A-3
Cuttable Trace Cross Reference. . . . . . . . . . . . . . . . . . . . . . A-16
ZT 8832 Cuttable Traces. . . . . . . . . . . . . . . . . . . . . . . . . . . . A-17
ZT 8832 STD Bus Loading, P Connector. . . . . . . . . . . . . . . B-4
ZT 8832 STD Bus Loading, E Connector. . . . . . . . . . . . . . . B-5
Tables
Table B–3
Table B–4
Table B–5
Table B–6
Table B–7
Table B–8
J1 Parallel Port Pinout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
J2 Serial Port (RS-232-C) Pinout. . . . . . . . . . . . . . . . . . . . .
J2 Serial Port (RS-422/485) Pinout. . . . . . . . . . . . . . . . . . .
J3 Counter/Timer and Interrupt Pinout. . . . . . . . . . . . . . . .
J4 SBX Expansion Module Pinout. . . . . . . . . . . . . . . . . . . .
J5 Serial Port Pinout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B-11
B-12
B-13
B-14
B-15
B-16
ILLUSTRATIONS
Figure 1–1
Figure 2–1
Figure 2–2
Figure 2–3
Figure 2–4
Figure 2–5
Figure 2–6
Figure 3–1
Figure 3–2
Figure 3–3
Figure 3–4
Figure 5–1
Figure 5–2
Figure 5–3
Figure 5–4
Figure 5–5
Figure 5–6
Figure 5–7
Figure 5–8
Figure 6–1
Figure 6–2
Figure 6–3
Figure 6–4
Figure 6–5
Figure 6–6
Figure 6–7
Figure 7–1
Figure 7–2
Figure 7–3
Figure 7–4
Figure 7–5
Figure 7–6
Figure 7–7
Functional Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
STD ROM Jumper Configuration. . . . . . . . . . . . . . . . . . . . . . 2-4
DOS MPX Jumper Configuration. . . . . . . . . . . . . . . . . . . . . . 2-9
Local CPU Memory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10
STD Bus CPU Memory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11
STD Bus CPU I/O. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
Local CPU I/O. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
STD Bus Control Port Architecture. . . . . . . . . . . . . . . . . . . 3-10
Local Control Port Architecture. . . . . . . . . . . . . . . . . . . . . . 3-13
Board Select Port Architecture. . . . . . . . . . . . . . . . . . . . . . . 3-16
Interrupt Status Port Architecture. . . . . . . . . . . . . . . . . . . . . 3-18
V40 Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
CPU Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
Processor Status Word. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14
RESET and READY Synchronization. . . . . . . . . . . . . . . . . 5-19
Memory Map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-24
Data Formats. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25
I/O Map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26
Interrupt Processing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29
On Chip Peripheral Connection Register. . . . . . . . . . . . . . . . 6-3
On Chip Peripheral Selection Register. . . . . . . . . . . . . . . . . . 6-4
Wait-Cycle 2 Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Wait-Cycle 1 Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Wait-Cycle Memory Boundary Register. . . . . . . . . . . . . . . . 6-9
Refresh Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10
Timer/Counter Clock Selection Register. . . . . . . . . . . . . . . 6-11
Counter/Timer Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . 7-4
Counter/Timer General Mode Register. . . . . . . . . . . . . . . . . 7-9
Counter/Timer Count Mode Register. . . . . . . . . . . . . . . . . . 7-10
Counter/Timer Multiple Mode Register. . . . . . . . . . . . . . . 7-11
Counter/Timer Count Register. . . . . . . . . . . . . . . . . . . . . . . 7-12
Counter/Timer Status Register. . . . . . . . . . . . . . . . . . . . . . . 7-13
Mode 0 Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-16
Illustrations
Figure 7–8
Figure 7–9
Figure 7–10
Figure 7–11
Figure 7–12
Figure 8–1
Figure 8–2
Figure 8–3
Figure 8–4
Figure 8–5
Figure 8–6
Figure 8–7
Figure 8–8
Figure 8–9
Figure 8–10
Figure 8–11
Figure 8–12
Figure 8–13
Figure 9–1
Figure 9–2
Figure 9–3
Figure 9–4
Figure 9–5
Figure 9–6
Figure 9–7
Figure 9–8
Figure 9–9
Figure 10–1
Figure 10–2
Figure 10–3
Figure 10–4
Figure 10–5
Figure 10–6
Figure 11–1
Figure 11–2
Figure 11–3
Figure 11–4
Figure 11–5
Figure 11–6
Figure 11–7
Figure 11–8
Mode 1 Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-19
Mode 2 Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-21
Mode 3 Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-23
Mode 4 Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-25
Mode 5 Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-27
ICU Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
Interrupt Initialization Programming. . . . . . . . . . . . . . . . . . . 8-8
Interrupt Initialization Word 1. . . . . . . . . . . . . . . . . . . . . . . . . 8-9
Interrupt Initialization Word 2. . . . . . . . . . . . . . . . . . . . . . . . 8-10
Interrupt Initialization Word 3. . . . . . . . . . . . . . . . . . . . . . . . 8-10
Interrupt Initialization Word 4. . . . . . . . . . . . . . . . . . . . . . . . 8-11
Interrupt Mask Word. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-12
Interrupt Priority and Finish Word. . . . . . . . . . . . . . . . . . . . 8-13
Interrupt Mode Word. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-15
Interrupt Status Registers IRQ and IIS. . . . . . . . . . . . . . . . 8-17
Interrupt Status Register IPOL. . . . . . . . . . . . . . . . . . . . . . . 8-18
CPU Interrupt Vector Processing. . . . . . . . . . . . . . . . . . . . . 8-21
Nested Interrupt Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . 8-23
DCU Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-4
DMA Initialization Command Register. . . . . . . . . . . . . . . . . 9-8
DMA Channel Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-9
DMA Base and Current Count Registers. . . . . . . . . . . . . . 9-10
DMA Base and Current Address Registers. . . . . . . . . . . . . 9-11
DMA Device Control Registers. . . . . . . . . . . . . . . . . . . . . . 9-12
DMA Mode Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-13
DMA Status Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-15
DMA Mask Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-16
SCU Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3
Serial Status Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-6
Serial Command Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-8
Serial Mode Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-9
Serial Interrupt Mask Register. . . . . . . . . . . . . . . . . . . . . . 10-10
SCU Serial Data Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-12
ACC Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4
Line Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-9
Line Status Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-11
Modem Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . . 11-13
Modem Status Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-15
Divisor Latch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-17
Interrupt Identify Register. . . . . . . . . . . . . . . . . . . . . . . . . . 11-18
Interrupt Enable Register. . . . . . . . . . . . . . . . . . . . . . . . . . . 11-19
Illustrations
Figure 11–9
Figure 12–1
Figure 13–1
Figure 14–1
Figure 15–1
Figure A–1
Figure A–2
Figure A–3
Figure A–4
Figure B–1
Figure B–2
Figure B–3
Figure B–4
Figure B–5
Figure B–6
Figure B–7
Figure B–8
Figure B–9
Figure B–10
Figure B–11
Figure B–12
Figure B–13
Figure B–14
Figure B–15
ACC Serial Data Format. . . . . . . . . . . . . . . . . . . . . . . . . . . 11-21
Parallel Port Functional Diagram. . . . . . . . . . . . . . . . . . . . . 12-3
Watchdog Timer Functional Diagram. . . . . . . . . . . . . . . . . 13-3
SBX Expansion Module Installation. . . . . . . . . . . . . . . . . . 14-5
8087 Numeric Data Processor Installation. . . . . . . . . . . . . 15-3
ZT 8832 Factory Default Configuration. . . . . . . . . . . . . . . A-14
Jumper Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-15
Cuttable Trace Locations, Component Side. . . . . . . . . . . A-21
Cuttable Trace Locations, Solder Side. . . . . . . . . . . . . . . . A-22
Board Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-7
STD 32 P/E Connector Pinout. . . . . . . . . . . . . . . . . . . . . . . . B-8
Connector Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-9
ZT 90014 Rev _ Serial I/O Cable. . . . . . . . . . . . . . . . . . . . B-17
ZT 90021 Rev _ Parallel I/O Cable. . . . . . . . . . . . . . . . . . . B-18
ZT 90090 Rev _ Parallel I/O Cable. . . . . . . . . . . . . . . . . . . B-18
ZT 90027 Rev _ Serial I/O Cable. . . . . . . . . . . . . . . . . . . . B-19
ZT 90068 Rev _ Parallel I/O Cable. . . . . . . . . . . . . . . . . . . B-20
ZT 90069 Rev _ Serial I/O Cable. . . . . . . . . . . . . . . . . . . . B-20
Standard Assembly Diagram. . . . . . . . . . . . . . . . . . . . . . . . B-21
SBX Expansion Module Read Timing. . . . . . . . . . . . . . . . B-22
SBX Expansion Module Write Timing. . . . . . . . . . . . . . . . B-23
SBX Expansion Module DMA Timing. . . . . . . . . . . . . . . . B-24
SBX Expansion Module Clock Timing. . . . . . . . . . . . . . . B-24
SBX Expansion Module Reset Timing. . . . . . . . . . . . . . . . B-25
Chapter 1
INTRODUCTION
Contents
Page
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Product Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Features of the ZT 8832 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Development Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
FUNCTIONAL BLOCKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
V40 (µPD70208) Processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Local Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Dual Port Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
Board Select Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
Serial Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
Parallel Input/Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
Interrupt Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Counter/Timers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Watchdog Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
zSBX Expansion Module Socket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
Numeric Data Processor Socket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
1-1
Introduction
OVERVIEW
This chapter provides a brief introduction to the ZT 8832. It includes
a product definition, a list of product features, a functional block
diagram, and a description of each block. Unpacking information and
installation instructions can be found in Chapter 2, "Getting Started."
Product Definition
The ZT 8832 is an 8MHz V40-based single board computer designed
to operate by itself or as an I/O control processor in an STD bus
system. The ZT 8832 increases system throughput by managing timecritical operations normally assigned to the STD bus master
processor. These operations include numerical computation, serial
communication, and digital I/O using resources local to the ZT 8832,
as well as a large selection of digital and analog I/O via the SBX
expansion module. Complex systems are simplified by partitioning
the design into smaller tasks and assigning these tasks to one or more
ZT 8832s.
The ZT 8832 and the STD bus master processor communicate
through 32 Kbytes of shared (dual port) RAM, and I/O mapped
control and status registers, located on the ZT 8832. These registers
include features such as maskable and non-maskable interrupt
generation between the ZT 8832 and the master processor.
Arbitration for the 32 Kbytes of dual ported RAM is implemented
entirely in hardware. The ZT 8832 also supports a board select option
that reduces the amount of STD bus addressing space needed in a
multiple ZT 8832 configuration. With board select, up to seven
ZT 8832s can be mapped into a single 32 Kbyte range.
1-2
Introduction
Features of the ZT 8832
•
STD 32 bus compatible
•
8088/8086 code compatible
•
One 32-pin EPROM socket (480 Kbyte capacity)
•
Two 32-pin RAM sockets (512 Kbyte capacity)
•
32 Kbyte dual port RAM (populated)
•
Optional battery backup on all RAM
•
Interrupt controller (V40)
•
Three 16-bit counter/timers (V40)
•
Three 8-bit parallel ports, Opto 22 compatible
•
Two serial ports (V40, 82050), RS-232/422/485
•
Two-stage watchdog timer
•
zSBX expansion module with DMA support
•
8087 Numeric Data Processor socket
•
20- or 24-bit STD bus memory address decoding
•
16-bit STD bus I/O address decoding
•
Programmable board select for multiple ZT 8832s
•
Software programmable LED
•
Pushbutton reset
•
Optional cables for parallel and serial interface
•
Optional STD ROM development/debug monitor
•
Optional DOS Multiprocessor Extension (DOS MPX) device
drivers
•
Five-year warranty
1-3
Introduction
Development Considerations
Ziatech offers two software development systems for ZT 8832
applications: STD ROM and DOS MPX.
STD ROM (Borland’s Turbo Debugger environment using
Paradigm Systems’ DEBUG/RT) connects the ZT 8832 to an IBMcompatible personal computer through a high speed serial link. The
computer is used as a development station to create, download, and
debug applications written in assembly, C, and other high level
languages. Paradigm’s DEBUG/RT used during the debug phase is
similar to Microsoft Codeview. It includes features such as source
level debugging, single stepping, breakpoints, watchpoints, and pull
down menus.
The DOS MPX package includes a boot ROM for the ZT 8832, an
installable device driver for the STD bus CPU, and a utility for
downloading programs to the ZT 8832. Also included is a utility to
permit several 8832s to share the same console as the STD bus CPU.
1-4
Introduction
Serial
RS-232
(3-Wire)
Counter/
Timer
and
Interrupts
Serial
RS-232
RS-485
Parallel
I/O
ZT 8832
NEC V40
Serial Port
RS-232 only
Serial
Port
RS-232/
RS-485
Parallel
I/O
24-bits
Local
EPROM
1 Socket
Local
RAM
2
Sockets
Watchdog
Timer
Lithium
Battery
DMA
Controller
Interrupt
Controller
Counter/
Timers
Numeric
Data
Processor
Socket
SBX Expansion Module
I/O Expansion Socket
Dual Port
RAM
Figure 1–1. Functional Block Diagram.
1-5
Introduction
FUNCTIONAL BLOCKS
Figure 1-1 illustrates the functional blocks of the ZT 8832. A
description of each block follows.
V40 (µPD70208) Processor
The NEC V40 is a highly integrated microprocessor that includes an
8088 compatible CPU and many standard I/O devices. The 8088
compatible CPU executes all code written for the 8088/8086 family of
microprocessors. In addition, the V40 instruction set includes
expanded rotate and shift, bit and nibble manipulation, and string I/O.
The standard I/O devices found in the V40 include an interrupt
controller (8259 architecture), counter/timers (8284 architecture), a
serial controller (8251 architecture), and a DMA controller. The V40
is fabricated with CMOS technology to provide an increase in both
temperature range and noise immunity with a reduction in power
consumption.
Local Memory
The ZT 8832 is populated with three 32-pin memory sockets dedicated for use by the V40 microprocessor. One socket supports 8K,
16K, 32K, 64K, 128K, and 512 Kbyte EPROMs. The remaining two
sockets each support 32 Kbyte and 128 Kbyte RAMs, with optional
battery backup. Additionally, one of the RAM sockets can be
configured to support a 512 Kbyte RAM. This memory is not
accessible by the STD bus CPU.
1-6
Introduction
Dual Port Memory
The ZT 8832 is populated with 32 Kbytes of RAM that is accessible
from both the local CPU and the STD bus CPU. Arbitration for
simultaneous access is done entirely in hardware. To increase system
performance, the dual port memory is physically separated from the
local memory. This permits the local CPU to continue executing local
operations while the STD bus CPU is accessing the dual port memory.
The STD bus CPU can also continue operations while the local CPU
accesses dual port memory. Only when both CPUs attempt a dual port
memory access is the operation of one suspended until the other is
completed. Repetitive access from both processors is interleaved on a
machine cycle basis. The dual port memory also supports software
programmable interrupts, a locking mechanism, and optional battery
backup. The locking mechanism allows either the STD bus CPU or
the local CPU to keep the other from accessing the dual port memory
until the lock is removed.
Board Select Option
One ZT 8832 occupies 32 Kbytes of STD memory addressing space.
For applications using multiple ZT 8832s, each can be mapped into a
unique 32 Kbyte space, or up to seven can be mapped into a common
32 Kbyte space by using the board select option. This option is
enabled by mapping each ZT 8832 to the same address range and a
unique board select address. In operation, all commonly mapped
ZT 8832s monitor the same I/O port for a board select address. To
communicate with a ZT 8832, the STD bus CPU writes the
appropriate board select address to the common I/O port. The STD
bus CPU is then free to communicate with the selected ZT 8832. It is
important to note that all functions local to the ZT 8832 continue to
operate when it is not selected by the STD bus CPU.
1-7
Introduction
Serial Communications
The ZT 8832 includes two asynchronous serial communication
channels, each with a programmable baud rate generator. The V40
provides one serial channel with an architecture similar to the
asynchronous portion of the 8251. Configured as RS-232 DTE, this
serial channel supports transmit data (TxD), receive data (RxD), and
ground. These signals are available through a 3-pin frontplane
connector. The optional 1 meter ZT 90069 cable is available to
connect the 3-pin connector to a male 25-pin D type connector.
The second serial channel (Intel 82050, or equivalent) is functionally
equivalent to the serial controller used in the IBM line of personal
computers. This channel supports all handshaking and modem control
signals and can be jumper programmed for RS-232 or RS-422/485.
Other features include loopback diagnostics, maskable interrupt
generation, and jumper selectable DCE or DTE configuration. The
82050 serial channel is accessed through a 14-pin frontplane
connector. The optional 1 meter ZT 90014 and ZT 90027 cables
connect the 14-pin connector to a male or female 25-pin D type
connector, respectively.
Parallel Input/Output
There are three 8-bit parallel ports on the ZT 8832, for a total of
24 I/O lines. Each I/O line can be programmed as input or as output
with readback. The I/O signals, fused power, and ground are
accessible through a 26-pin frontplane connector. The optional
1 meter ZT 90068 cable is available to connect the 26-pin connector
directly to an 8-, 16-, or 24-position I/O module mounting rack, such
as Ziatech’s ZT 2226 or the rack offered by Opto 22.
1-8
Introduction
Interrupt Controller
The ZT 8832 includes an eight-input programmable interrupt
controller with an 8259 architecture. Features of the interrupt
controller include level- and edge-triggered sensing, fixed and rotating
priorities, and the ability to mask individual inputs. Two of the
interrupt request inputs are available through a frontplane connector,
to be used as needed by the application. The remaining inputs are
dedicated to interrupt sources such as counter/timers for timed or
periodic interrupt generation, serial controllers for interrupt driven
data transfers, zSBX expansion module for interrupt driven I/O, and
the STD bus to support interrupt-driven data transfers from the STD
bus CPU through dual port memory.
Counter/Timers
The ZT 8832 has three independent 16-bit counter/timers with an
8254 architecture that can be used as timers or as event counters.
There are six programmable counter/timer modes: interrupt on end of
count, frequency divider, square wave generator, software-triggered,
hardware-triggered, and retriggerable one-shot. One of the
counter/timers is available through a frontplane connector, to be used
as required by the application. The other two counter/timers are
dedicated to uses such as baud rate generation for the V40 serial
channel and interrupt generation for timed and periodic interrupts.
Watchdog Timer
The ZT 8832 includes a two-stage watchdog timer. The main function
of a watchdog timer is to monitor system operation and take
corrective action if the system fails to operate as designed. While in
operation, the watchdog timer must be strobed at a predetermined rate
by toggling a parallel port bit. Failure to strobe the watchdog results
in a non-maskable interrupt to the V40. The ZT 8832 is reset unless
the non-maskable interrupt service routine takes corrective action that
includes strobing the watchdog timer within a certain time period.
The watchdog timer is enabled through jumper selection.
1-9
Introduction
zSBX Expansion Module Socket
The zSBX expansion module socket is provided to customize the I/O
capabilities of the ZT 8832 to the needs of the application. The
expansion module interface is electrically, mechanically, and
functionally equivalent to the Intel iSBX MULTIMODULE
standard, including DMA support for high speed transfers to ZT 8832
memory. This makes hundreds of off-the-shelf modules available to
the STD bus designer. Functions available include servo and step
motor control, analog-to-digital and digital-to-analog conversion,
serial and parallel I/O, graphics, and modem control. There are also
prototyping boards for those who need to design custom I/O.
Numeric Data Processor Socket
The math capabilities of the V40 include addition, subtraction,
multiplication, and division of 8-bit and 16-bit numbers. The STD bus
is often used in numerically intensive applications needing more
powerful arithmetic operations than those provided by the V40. These
requirements are realized with the addition of an 8087 Numeric Data
Processor (NDP) to the ZT 8832. Simply plugging the NDP into the
empty socket on the ZT 8832 provides 68 added instructions for
extended arithmetic, trigonometric, exponential, and logarithmic
functions. These added instructions are supported by seven additional
data types including integers (16-, 32-, and 64-bit), floating point (32-,
64-, and 80-bit), and BCD (18-digit). Using the NDP increases
performance up to 100 times that of equivalent routines implemented
in software.
1-10
Chapter 2
GETTING STARTED
Contents
Page
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
UNPACKING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
WHAT’S IN THE BOX? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
SYSTEM REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
ZT 8832 Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
ZT 88CT32 Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
INSTALLING THE ZT 8832 WITH STD ROM . . . . . . . . . . . . . . . . . . . . . 2-5
Memory Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Cable Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Jumper Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
INSTALLING THE ZT 8832 WITH DOS MPX . . . . . . . . . . . . . . . . . . . . . 2-7
Memory Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Cable Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Jumper Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
MEMORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10
I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
JUMPER OPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14
OVERVIEW
This chapter provides a summary of the information essential to
getting the ZT 8832 operational. Read this chapter before attempting
to use the board.
2-1
Getting Started
UNPACKING
Please check the shipping carton for damage. If the shipping carton
and contents are damaged, notify the carrier and Ziatech for an
insurance settlement. Retain the shipping carton and packing material
for inspection by the carrier. Do not return any product to Ziatech
without a Return Material Authorization (RMA) number.
Appendix C explains the procedure for obtaining an RMA number
from Ziatech.
WHAT’S IN THE BOX?
The items listed below are included in a standard ZT 8832 order.
System level products, such as the STD ROM and DOS MPX,
include additional items not shown. If you have ordered a system
level product, refer to the system manual for the packing list.
•
ZT 8832 I/O Control Processor in anti-static bag
•
Optional ZT 8832 Operating Manual in binder
•
Anti-static packing material
Attach the sticker packaged with the manual to the spine of the binder
for easy identification. Save the anti-static packing material for
storing or returning the ZT 8832.
WARNING!
Like all equipment utilizing MOS devices, the ZT 8832 must
be protected from static discharge. Never remove or install
any of the socketed parts except at a static-free work station.
2-2
Getting Started
SYSTEM REQUIREMENTS
The ZT 8832 is designed for use with or without an STD bus
backplane. For STD bus applications, the ZT 8832 is mechanically
and electrically compatible with Version 1.1 of the STD 32 Bus
Specification and Designer’s Guide.
Vertical mounting is recommended in applications not using a fan.
Horizontal mounting requires a minimum air flow of 30 cubic
feet/min. passing over the surface of the board.
Refer to Appendix B for additional specifications.
ZT 8832 Requirements
The ZT 8832 requires +5 VDC ±5% at 1.5 A maximum, +12 VDC
±10% at 0.10 A maximum, and -12 VDC ±10% at 0.10 A maximum.
The ambient temperature range must be maintained between 0 and
+65˚ Celsius to guarantee proper operation and to avoid damage.
Relative humidity must be less than 95% at 40˚ Celsius, noncondensing.
ZT 88CT32 Requirements
The ZT 88CT32 requires +5 VDC ±5% at 0.5 A maximum, +12 VDC
±10% at 0.10 A maximum, and -12 VDC ±10% at 0.10 A maximum.
The ambient temperature range must be maintained between -40˚ and
+85˚ Celsius to guarantee proper operation and to avoid damage.
Relative humidity must be less than 95% at 40˚ Celsius, noncondensing.
2-3
P1
2-4
W28
W29
W30
W31
W32
W33
W34
W35
W36
W37
W38
W39
W40
W41
W42
W43
W44
W45
W46
ZT 8832 ICP
J4
32 KBYTE SRAM
STD ROM EPROM
W20
W21
W22
W16, W17
W23
W24, W25
W26, W27
W15
W9
W10
W11
W12
W13
W14
W7
W1
W2
W3
W4
W5
W6
W8
J5
J1
J2
J3
Getting Started
Figure 2–1. STD ROM Jumper Configuration.
Getting Started
INSTALLING THE ZT 8832 WITH STD ROM
The fastest way to begin using the ZT 8832 is with the addition of
development software from Ziatech. The STD ROM development
system connects the ZT 8832 to an IBM-compatible personal
computer through a serial link. The personal computer is used as a
development station to create, download, and debug applications
written in assembly, C, and other high level languages.
If the ZT 8832 and STD ROM are ordered together, Ziatech
configures the ZT 8832 and tests the system level operation. If the
ZT 8832 and STD ROM are ordered separately, or the system has
been altered and no longer functions properly, refer to Figure 2-1 and
check the following configuration requirements.
Memory Requirements
The STD ROM firmware is shipped in a 64 Kbyte EPROM. Install
the EPROM into the ZT 8832 socket labeled ROM. The 28-pin device
must be right-justified in the 32-pin socket, as shown in Figure 2-1.
STD ROM requires 2 Kbytes of RAM memory, from address 0
through 7FFh. Installing a 32 Kbyte RAM in the socket labeled RAM
LOW meets this requirement. The 28-pin device must be rightjustified in the 32-pin socket, as shown in Figure 2-1. If more than
32 Kbytes is needed, a second 32 Kbyte device can be added to the
RAM HIGH socket, or larger RAM devices can be used.
Cable Requirements
STD ROM requires a serial link between the ZT 8832 and the
terminal or PC. The ZT 90069 cable shipped with the STD ROM
system is used for this purpose. Plug the cable into the J5 connector of
the ZT 8832 as shown in Figure 2-1.
2-5
Getting Started
Jumper Requirements
Table 2-1 and Figure 2-1 show the correct jumper positioning for the
ZT 8832 configured to support STD ROM.
Table 2-1
STD ROM Jumper Configuration.
Installed
W1-6, 8, 11, 12, 14-16, 21-23, 25, 27,
29, 30, 37, 39, 41-43, 46
Removed
W7, 9, 10, 13, 17-20, 24, 26, 28, 31-36,
38, 40, 44, 45
Operation
Refer to the STD ROM documentation for software installation and
operation procedures.
2-6
Getting Started
INSTALLING THE ZT 8832 WITH DOS MPX
The DOS Multiprocessing Extension (MPX) software provides a
development and operating environment for one or more ZT 8832s in
a DOS application. DOS MPX allows programmers to develop
applications using a high-level language such as C without the
problems associated with placing the program in ROM.
DOS MPX includes a boot EPROM for the ZT 8832, an installable
device driver for the system master processor, and a utility for
downloading programs from the master processor to the ZT 8832.
Memory Requirements
The DOS MPX firmware is shipped in a 64 Kbyte EPROM. Install
the EPROM into the ZT 8832 socket labeled ROM. The 28-pin device
must be right justified in the 32-pin socket, as shown in Figure 2-2.
DOS MPX requires at least 32 Kbytes of local RAM. Installing a
32 Kbyte RAM in the socket labeled RAM LOW meets this
requirement. The 28-pin device must be right-justified in the 32-pin
socket, as shown in Figure 2-2. If more than 32 Kbytes is needed, a
second 32 Kbyte device can be added to the RAM HIGH socket, or
larger RAM devices can be used.
Cable Requirements
DOS MPX shares video and keyboard with the system master
processor. The only cabling required is that dictated by the application
requirements.
2-7
Getting Started
Jumper Requirements
Table 2-2 and Figure 2-2 show the correct jumper positioning for the
ZT 8832 configured to support DOS MPX. This is the same jumper
configuration required for STD ROM.
Table 2-2
DOS MPX Jumper Configuration.
Installed
W1-6, 8, 11, 12, 14-16, 21-23, 25, 27,
29, 30, 37, 39, 41-43, 46
Removed
W7, 9, 10, 13, 17-20, 24, 26, 28, 31-36,
38, 40, 44, 45
Operation
Refer to the DOS MPX documentation for software installation and
operation procedures.
2-8
P1
W28
W29
W30
W31
W32
W33
W34
W35
W36
W37
W38
W39
W40
W41
W42
W43
W44
W45
W46
ZT 8832 ICP
J4
32 KBYTE SRAM
DOS MPX EPROM
W20
W21
W22
W16, W17
W23
W24, W25
W26, W27
W15
W9
W10
W11
W12
W13
W14
W7
W1
W2
W3
W4
W5
W6
W8
J5
J1
J2
J3
Getting Started
Figure 2–2. DOS MPX Jumper Configuration.
2-9
Getting Started
MEMORY
The ZT 8832 includes memory that is addressable by the local CPU
and memory that is dual ported between the local and STD bus CPU.
This is shown in two memory maps: Figure 2-3 illustrates the address
ranges of the memory devices available to the local CPU, and
Figure 2-4 illustrates the address ranges of the memory devices
available to the STD bus CPU.
The local ROM is a single memory device located in a 32-pin JEDEC
socket. While this socket is jumper configurable to support 8K, 16K,
32K, 64K, 128K, 256K, and 512 Kbyte devices, the ROM address
range is always 88000h through FFFFFh. This means that 8K, 16K,
32K, 64K, 128K, and 256 Kbyte devices are redundantly mapped, and
only 480 Kbytes of the 512 Kbyte device is used. Please note that
while the 256K and 512 Kbyte devices are supported, they may not be
currently available. The access time of the local ROM device must
not be greater than 250 ns. This ROM is not addressable by the STD
bus CPU.
FFFFFh
Local ROM
88000h
87FFFh
Dual Port RAM
80000h
7FFFFh
Local RAM
00000h
Figure 2–3. Local CPU Memory.
2-10
Getting Started
The dual port RAM is a 32 Kbyte RAM populated on the ZT 8832. It
is shown on both local and STD bus memory maps because, even
through it is the same physical memory, it is accessible from both the
local CPU and the STD CPU. The address range of the dual port
RAM as seen by the local CPU is fixed from 80000 through 87FFFh.
The address range of the dual port RAM as seen by the STD bus CPU
is jumper selectable to any 32 Kbyte memory block within a 1 Mbyte
address range of an STD bus CPU. Some STD bus microprocessors
support a 16 Mbyte address range by generating a 24-bit memory
address. The ZT 8832 can be configured to jumper select the dual port
RAM into any 32 Kbyte memory block within this 16 Mbyte address
range. As shipped, the address range is XC8000 through XCFFFFh.
The local RAM consists of two contiguously mapped 32-pin JEDEC
sockets. The sockets are shipped to support 32 Kbyte RAM devices.
Jumper options also permit both sockets to support 128 Kbyte
devices, and one of the sockets to support a 512 Kbyte device. Please
note that while the 512 Kbyte RAM is supported by the ZT 8832, it
may not be currently available. The access time of the local RAM
devices must not be greater than 250 ns. This RAM is not addressable
by the STD bus CPU.
XFFFFFh
Not Used
XD0000h
XCFFFFh
Dual Port RAM
XC8000h
XC7FFFh
Not Used
X00000h
Figure 2–4. STD Bus CPU Memory.
2-11
Getting Started
I/O
The ZT 8832 includes some I/O devices addressable by the local CPU
and other I/O devices addressable by the STD bus CPU. This is
shown in two I/O maps. Figure 2-6 illustrates the devices accessible
by the local CPU. Figure 2-5 illustrates the devices available to the
STD bus CPU. Note that none of the I/O devices are accessible from
both the local CPU and the STD bus CPU.
FFFFh
8000h
7FFFh
7FF8h
7FF7h
7FF0h
7FEFh
0000h
Not Used
Board Select (Write)
Interrupt Status (Read)
STD Bus Control Port
Not Used
Figure 2–5. STD Bus CPU I/O.
Several I/O devices available to the local CPU must be enabled and
mapped by programming the V40 configuration registers. These
devices are the interrupt controller, counter/timers, DMA controller,
and V40 serial controller. The address mapping of all other local I/O
devices is fixed to the locations shown in Figure 2-6. Note that these
I/O devices are not accessible by the STD bus CPU.
The ZT 8832 requires 16 consecutive STD bus I/O port addresses.
The STD bus control port is a single byte value redundantly mapped
over the lower eight addresses. The STD bus control port can only be
written; no readback is available. The upper eight addresses are
shared between the Board Select and Interrupt Status Port. Both the
Board Select and Interrupt Status Ports are redundantly mapped single
byte values. The Board Select Port can only be written; no readback
is available. The Interrupt Status Port can only be read.
2-12
Getting Started
FFF0-FFFFh
V40 Configuration
0400-FFEFh
Not Used
03F0-03FFh
82050 Serial Port
0380-03EFh
Not Used
0300-037Fh
SBX Module - Select 1
0280-02FFh
SBX Module - Select 0
0240-027Fh
Not Used
0230-023Fh
Local Control Port
0220-022Fh
Parallel Port 2
0210-021Fh
Parallel Port 1
0200-020Fh
Parallel Port 0
00E0-01FFh
Not Used
00D0-00DFh
DMA Controller [1]
00B8-00CFh
Not Used
00B0-00B7h
V40 Serial Port [1]
0048-00AFh
Not Used
0040-0047h
Counter/Timers [1]
0028-003Fh
Not Used
0020-0027h
Interrupt Controller [1]
0000-0001Fh
Not Used
[1] These devices are internal to the V40 and must be enabled and mapped
through software configuration.
Figure 2–6. Local CPU I/O.
2-13
Getting Started
JUMPER OPTIONS
The ZT 8832 includes several jumper options that tailor the operation
of the board to the requirements of specific applications. Refer to
Appendix A for a description of configurable jumpers.
2-14
III. USER’S REFERENCE
THEORY OF OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
APPLICATION EXAMPLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
PROCESSOR DESCRIPTION (V40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
PROCESSOR CONFIGURATION (V40) . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
COUNTER/TIMERS (V40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
INTERRUPT CONTROLLER (V40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1
DMA CONTROLLER (V40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1
SERIAL COMMUNICATIONS (V40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1
SERIAL COMMUNICATIONS (82050) . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1
PARALLEL I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1
WATCHDOG TIMER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1
SBX EXPANSION MODULE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-1
NUMERIC DATA PROCESSOR (8087) . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-1
Chapter 3
THEORY OF OPERATION
Contents
Page
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
COMMONLY ASKED QUESTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
DUAL PORT MEMORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
STD BUS AND LOCAL CONTROL PORTS . . . . . . . . . . . . . . . . . . . . . . . 3-9
STD Bus Control Port Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
STD Bus Control Port Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
STD Bus Control Port Programmable Reset . . . . . . . . . . . . . . . . 3-12
Local Control Port Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
Local Control Port Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13
BOARD SELECT OPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
STD BUS INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17
RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21
3-1
Theory of Operation
OVERVIEW
This chapter presents a detailed description of ZT 8832 system level
operation. Topics discussed include:
•
Commonly asked questions regarding the ZT 8832
•
Issues surrounding STD bus compatibility
•
Operation of dual port memory and control port I/O used to
interface the ZT 8832 to the STD bus
•
Using the board select option to reduce STD bus memory and
I/O requirements in a system with more than one ZT 8832
•
Using STD bus interrupts
•
The reset state of the ZT 8832 and the relationship between reset
on the ZT 8832 and reset on the STD bus
3-2
Theory of Operation
COMMONLY ASKED QUESTIONS
1.
What software development tools are available?
Ziatech supports two software development tools for the
ZT 8832: STD ROM and DOS Multiprocessing Extension
(DOS MPX).
The STD ROM software includes a PROM based debugger and
a PC based floppy disk. The ZT 8832 is connected to a PC
through a serial link. Programs are developed on the PC and
transferred across the serial link to the ZT 8832 for debugging.
DOS MPX provides software support for one or more ZT 8832s
in an STD bus application running under Ziatech DOS. The
DOS MPX package includes a boot ROM for the ZT 8832, an
installable device driver for the STD bus CPU, and a utility for
downloading programs to the ZT 8832. Also included is a
Virtual Processor Console (VPC) utility to multiplex several
ZT 8832s and the STD bus CPU on a single console.
3-3
Theory of Operation
2.
Are emulators available for the NEC V40?
Yes. Several manufacturers of V40 emulators are listed below.
3-4
Tektronix, Inc.
P.O. Box 4828
Portland, OR 97208
(818) 999-1711
Sophia Computer Systems
3337 Kifer Road
Santa Clara, CA 95051
(408) 733-1571
Zax Corporation
2572 White Road
Irvine, CA 92714
(714) 474-1170
American Automation
14731 Franklin Avenue
Tustin, CA 92680
(714) 731-1661
Hewlett-Packard
1501 Page Mill Road
Palo Alto, CA 94304
Eastern (301) 258-2000
Midwestern (312) 255-9800
Southern (404) 955-1550
Western (818) 508-2319
Theory of Operation
3.
Can the ZT 8832 access STD bus memory and I/O?
The ZT 8832 includes 32 Kbytes of dual port RAM mapped into
the STD bus memory addressing space. This is the only STD
bus memory accessible by the local CPU. The local CPU does
not have access to any STD bus I/O.
4.
Can the STD bus CPU access memory and I/O local to the
ZT 8832?
The STD bus CPU has access to 32 Kbytes of dual port RAM
local to the ZT 8832. The three 32-pin JEDEC sockets are not
available to the STD bus CPU. The ZT 8832 includes 16 I/O
ports that are accessible by the STD bus CPU. This I/O is
divided into the STD bus control port, board select port, and
interrupt status port. This is the only I/O on the ZT 8832
available to the STD bus CPU.
5.
How does the ZT 8832 compare with Ziatech’s earlier I/O
control processor, the ZT 8830?
The ZT 8832 and ZT 8830 are both designed to increase the
modularity and performance of STD bus applications through
parallel processing. Both boards include 32 Kbytes of dual port
RAM accessible by both the STD bus CPU and the CPU local to
the board. Both boards also include an SBX expansion module
for I/O expansion with off-the-shelf or custom I/O. It should be
noted that the SBX expansion module connector is in the same
place on both boards; this permits custom SBX designs for the
ZT 8830 to be used on the ZT 8832.
3-5
Theory of Operation
The ZT 8832 is a newer generation board that removes many of
the restrictions found on the ZT 8830. The major differences are
outlined below.
3-6
•
Increased performance. Both the ZT 8830 and ZT 8832
are based on an 8 MHz microprocessor with an 8088
architecture. The major performance increase of the
ZT 8832 is realized in the dual port memory design. On
the ZT 8830, all local memory is dual ported. This means
that the local CPU is suspended any time the STD bus
CPU accesses the ZT 8830. The ZT 8832 separates the
dual port memory from local memory so the local CPU
continues to operate while the STD bus CPU accesses the
dual port memory. It is not until both CPUs attempt a dual
port access that one is suspended until the other has
completed its dual port access. The ZT 8832 also supports
DMA on the SBX expansion module for high speed I/O
transfers and an 8087 Numeric Data Processor for math
operations up to 100 times faster than possible with a
ZT 8830.
•
Reduced STD bus memory requirements. The ZT 8830
supports 32 Kbytes of EPROM and 32 Kbytes of RAM, all
of which are dual ported. This means that each ZT 8830
requires 64 Kbytes of STD bus memory. This requirement
is compounded when multiple ZT 8830s are used in a
single system. The ZT 8832 requires only 32 Kbytes of
STD bus memory for the dual port RAM. The ZT 8832
also supports a board select option that permits up to seven
ZT 8832s to be mapped into a single 32 Kbyte STD bus
address range.
Theory of Operation
•
6.
More local memory. The ZT 8830 supports a maximum
of 32 Kbytes of RAM and 32 Kbytes of EPROM. With
memory devices currently available on the market, the
ZT 8832 supports 256 Kbytes of RAM and 128 Kbytes of
EPROM. When larger devices become available, the
ZT 8832 can be expanded to 512 Kbytes of RAM and
480 Kbytes of EPROM.
How many ZT 8832s can be used in a system?
The number of ZT 8832s is limited by the number of slots in the
STD bus card cage and power supply capabilities.
7.
Can the ZT 8832 operate without an STD bus backplane?
The ZT 8832 is designed to operate with or without an STD bus
backplane. It can be useful to operate small dedicated control
applications without a backplane when the ZT 8832 contains all
of the I/O needed.
3-7
Theory of Operation
DUAL PORT MEMORY
The ZT 8832 is shipped with 32 Kbytes of dual port RAM. Dual port
means that is it accessible by both the ZT 8832 CPU and the STD bus
CPU. The dual port memory is physically separate from the ZT 8832
local memory to permit the local CPU to continue operating even
during a dual port access by the STD bus CPU. It is not until both
CPUs attempt a simultaneous dual port access that arbitration logic
suspends the operation of one CPU until the other is completed. For
continuous accesses by both CPUs, the arbitration logic alternates the
access grant on a machine cycle boundary to ensure both processors
equal time. The arbitration is done entirely in hardware.
While using the dual port is as simple as writing to a standard
memory device, it may be beneficial to implement interrupt driven or
locked transfers. These are supported through the STD bus control
port and the local control port discussed on the following pages. Note
that the dual port RAM is battery backed if the optional battery is
installed.
3-8
Theory of Operation
STD BUS AND LOCAL CONTROL PORTS
The STD bus and local control ports increase the control and
flexibility of the communication link between the STD bus and the
ZT 8832.
STD Bus Control Port Overview
The STD bus control port is an I/O mapped device programmed by
the STD bus CPU to perform the following operations.
•
Generate maskable and non-maskable interrupts
•
Lock dual port access
•
Reset the maskable interrupt generated by the local CPU
•
Reset the ZT 8832
The STD bus CPU control port does not have readback capabilities
and is not accessible by the local CPU.
3-9
Theory of Operation
STD Bus Control Port Architecture
Figure 3-1 shows the architecture of the STD bus control port. Bit
definitions are given on the following pages.
Note: Writing a 0Fh followed by a logical 0 to the STD bus control
port resets the ZT 8832.
7
6
5
4
3
2
1
0
—
—
—
— SMR SLK SNI SMI
Register:STD Bus Control Port
Address:30h
Access:Write
Maskable Interrupt to Local CPU
0 No interrupt
1 Interrupt
Non-Maskable Interrupt to Local CPU
0 No interrupt
1 Interrupt
Lock Out Local CPU Dual Port
Access
0 No lock
1 Lock
Reset STD Bus Maskable Interrupt
Request
0 No reset
1 Reset
Figure 3–1. STD Bus Control Port Architecture.
The STD Bus Control Port Maskable Interrupt (SMI) bit (bit 0) is
programmed by the STD bus CPU to generate a maskable interrupt to
the local CPU. The SMI bit is connected to interrupt request 5 (IR5)
of the interrupt controller. The local CPU must complete the
following operations before the SMI bit is active:
•
3-10
Enable the interrupt controller with the OPCN V40 configuration register, as discussed in Chapter 6;
Theory of Operation
•
Program the interrupt controller to enable IR5, as discussed in
Chapter 8;
•
Remove the hardware mask by programming the LMR bit of the
local control port with a logical 0.
After the local CPU has performed these operations, the STD bus
CPU generates a maskable interrupt to the local CPU by writing a
logical 1 to the SMI bit of the STD bus control port. After a logical 1
is written by the STD bus CPU, all other writes to the SMI bit are
ignored until the interrupt request is cleared by the local CPU writing
a logical 1 followed by a logical 0 to the LMR bit of the local control
port.
The STD Bus Control Port Non-maskable Interrupt (SNI) bit (bit 1) is
programmed by the STD bus CPU to generate a non-maskable
interrupt to the local CPU. The STD bus CPU generates a nonmaskable interrupt to the local CPU by writing a logical 1 followed
by a logical 0 to the SNI bit. The SNI bit shares the non-maskable
interrupt with the jumper selectable watchdog timer and the optional
numeric data processor. While there is no status available to the local
CPU that indicates SNI is active, there is status for both the watchdog
timer and the numeric data processor. This means that if more than
one of the non-maskable interrupt sources is used, the local CPU can
determine that the SNI bit generated a request by eliminating the other
possible sources through polling.
The STD Bus Control Port Lock Dual Port Access (SLK) bit (bit 2) is
programmed by the STD bus CPU to prevent the local CPU from
accessing the dual port RAM. The STD bus CPU arms Lock by
programming the SLK bit with a logical 1. At this point, the local
CPU can still access the dual port RAM. It is not until the STD bus
CPU performs the first read, or a write of the dual port RAM, that the
local CPU is no longer granted access. Any attempt by the local CPU
to access dual port RAM is denied, suspending local CPU operation
until the STD bus CPU programs SLK with a logical 0.
3-11
Theory of Operation
The STD Bus Control Port Maskable Interrupt Reset (SMR) bit (bit 3)
is programmed by the STD bus CPU to reset an active STD bus
maskable interrupt request generated by the local CPU through the
LMI bit of the local control port. The Interrupt Status Port (ISP) is
available to the STD bus CPU to determine if the local control port
LMI bit is active. The STD bus CPU must first program the SMR bit
with a logical 0 to enable the local CPU to generate a maskable
interrupt. To reset an active maskable interrupt, the STD bus CPU
must program the SMR bit with a logical 1 followed by a logical 0.
STD Bus Control Port Programmable Reset
The STD bus CPU resets the local CPU by writing a 0Fh to the STD
bus control port followed by a logical 0. This software programmable
reset does not affect the STD bus. The ZT 8832 enters reset a
maximum of 250 ms after the 0Fh is written and remains reset until
the logical 0 is written. The STD bus CPU should not access the
ZT 8832 before the logical 0 is written.
Local Control Port Overview
The local control port is an I/O mapped device programmed by the
local CPU to perform the following operations.
•
Generate maskable and non-maskable interrupts
•
Lock dual port access
•
Reset the maskable interrupt generated by the STD bus CPU
The local control port does not have readback and is not accessible by
the STD bus CPU.
3-12
Theory of Operation
Local Control Port Architecture
Figure 3-2 shows the architecture of the local control port. Bit
definitions are given on the following pages.
Note: The STD bus cannot be reset through the local control port. All
other functions are symmetrical between the STD bus control port and
the local control port.
7
6
5
4
3
2
1
0
—
—
—
— LMR LLK LNI LMI
Register:Local Control Port
Address:230h
Access:Write
Maskable Interrupt to STD Bus CPU
0 No interrupt
1 Interrupt
Non-Maskable Interrupt to STD Bus
CPU
0 No interrupt
1 Interrupt
Lock Out STD Bus CPU Dual Port
Access
0 No lock
1 Lock
Reset Local CPU Maskable Interrupt
Request
0 No reset
1 Reset
Figure 3–2. Local Control Port Architecture.
The Local Control Port Maskable Interrupt (LMI) bit (bit 0) is
programmed by the local CPU to generate a maskable interrupt to the
STD bus CPU. The LMI bit is connected to the STD bus INTRQ*
(pin 44), INTRQ1* (pin 37), or INTRQ2* (pin 50) through jumper
selection. Before the LMI bit is programmed, the STD bus CPU must
program the SMR bit of the STD bus control port with a logical 0.
Once this is done, the local CPU generates a maskable interrupt to the
STD bus CPU by writing a logical 1 to the LMI bit of the local
control port. After a logical 1 is written by the local CPU, all other
3-13
Theory of Operation
writes to the LMI bit are ignored until the interrupt request is cleared
by the STD bus CPU writing a logical 1 followed by a logical 0 to the
SMR bit of the STD bus control port.
The Local Bus Control Port Non-Maskable Interrupt (LNI) bit (bit 1)
is programmed by the local CPU to generate a non-maskable interrupt
to the STD bus CPU. The local CPU generates a non-maskable
interrupt to the STD bus CPU by writing a logical 1 followed by a
logical 0 to the LNI bit. The ZT 8832 does not provide any status to
the STD bus CPU that flags an active non-maskable interrupt request.
If this is necessary for the application, a status word can be
implemented in the dual port RAM.
The Local Control Port Lock (LLK) bit (bit 2) is programmed by the
local CPU to prevent the STD bus CPU from accessing the dual port
RAM. The local CPU arms Lock by programming the LLK bit with a
logical 1. At this point, the STD bus CPU can still access the dual
port RAM. It is not until the local CPU performs the first read, or a
write of the dual port RAM, that the STD bus CPU is no longer
granted access. Any attempt by the STD bus CPU to access dual port
RAM is denied, suspending STD bus CPU operation until the local
CPU programs LLK with a logical 0.
The Local Control Port Maskable Interrupt Reset (LMR) bit (bit 3) is
programmed by the local CPU to reset an active maskable interrupt
request generated by the STD bus CPU through the SMI bit of the
STD bus control port. The local CPU must first program the LMR bit
with a logical 0 to enable the STD bus CPU to generate a maskable
interrupt. To reset an active maskable interrupt, the local CPU must
program the LMR bit with a logical 1 followed by a logical 0.
3-14
Theory of Operation
BOARD SELECT OPTION
A ZT 8832 occupies 32 Kbytes of STD bus memory address space
and 16 bytes of STD bus I/O address space. The memory is jumper
selectable to any 32 Kbyte block and the I/O is jumper selectable to
any of 16 possible locations. Systems using multiple ZT 8832s can
map each one to a unique memory and I/O address range. However,
in some systems this may not be possible because of limited STD bus
resources. The board select option solves this problem by reducing
the memory and I/O requirements of up to seven ZT 8832s to those of
a single ZT 8832; up to 14 ZT 8832s to those of two ZT 8832s; and
so on.
Follow the steps listed below to begin using the board select option.
The mapping options discussed below are found in the jumper table
beginning on page A-2.
1.
Map the dual port RAM of each ZT 8832 to the same STD bus
memory addressing range.
2.
Map the STD bus control port, board select port, and interrupt
status port of each ZT 8832 to the same STD bus I/O address
range.
3.
Jumper program a unique board select address for each
ZT 8832. Please note that with three jumpers there are eight
combinations. One combination is used to disable the board
select feature, leaving seven unique combinations for up to
seven boards.
3-15
Theory of Operation
After the above steps are completed, install the ZT 8832s into the
STD bus card cage. The ZT 8832s power up not selected. This means
that the dual port RAM, STD bus control port, and interrupt status
port are not accessible by the STD bus CPU. The Board Select Port is
the only port accessible. To begin communicating with a ZT 8832, the
STD bus CPU must write the board select address of that ZT 8832 to
the Board Select Port (see Figure 3-3). After the board select address
is written, the STD bus CPU is free to communicate with the ZT 8832
as though there were no bank selection. To begin communicating with
a different ZT 8832, the STD bus CPU simply writes the new board
select address. This automatically switches out the currently enabled
ZT 8832 and switches in the new one.
7
6
5
4
3
2
1
0
—
—
—
—
—
S2 S1 S0
Register:Board Select
Address:38h
Access:Write
Board Select Address
1
000 All selected
001 1
010 2
011 3
100 4
101 5
110 6
111 7
1Programming the All Selected address selects the ZT 8832 regardless of the jumper
programmed board select address. This operation is useful for writing the same data to the dual
port RAM or control port of all ZT 8832s at the same time.
Warning: Do not perform an STD bus read from the ZT 8832 dual port RAM or I/O if the All
Selected option is programmed; this may damage the STD bus system.
Figure 3–3. Board Select Port Architecture.
3-16
Theory of Operation
STD BUS INTERRUPTS
The ZT 8832 is capable of generating maskable and non-maskable
interrupts to the STD bus CPU. The maskable interrupt is jumper
selectable to the STD bus INTRQ* (pin 44), INTR1* (pin 37), or
INTRQ2* (pin 50). The non-maskable interrupt is dedicated to the
STD bus NMIRQ* (pin 46). This section discusses the issues
surrounding the use of the ZT 8832 and STD bus interrupts.
The local CPU generates a non-maskable interrupt to the STD bus
CPU by writing to the local control port. The ZT 8832 does not
provide any status to the STD bus master to indicate that it generated
the non-maskable interrupt. If it is necessary to distinguish between
multiple sources of non-maskable interrupt, the application software
can implement a status byte in the dual port RAM. In general, nonmaskable interrupts are reserved for orderly shutdown of a system in
response to a catastrophic event.
There are several issues surrounding the use of maskable interrupts.
The first thing to determine is which STD bus interrupts are supported
by the STD bus CPU. Most STD bus CPU boards support INTRQ*;
many of the newer models also support INTRQ1* and INTRQ2*. For
example, the ZT 8806/8807 supports INTRQ*, while the
ZT 8808/8809 and ZT 8816/8817 (revision B and later) support
INTRQ*, INTRQ1*, and INTRQ2*. If the STD bus CPU supports
more than one interrupt request, the next thing to determine is which
to use. The best choice is to use an interrupt request that is not shared
with other STD bus boards. This greatly simplifies the application
software. Once the STD bus interrupt request is selected, the ZT 8832
must be jumper configured to support it.
3-17
Theory of Operation
The simplest interrupt architecture is one in which the ZT 8832 does
not share the interrupt with any other STD bus boards, including other
ZT 8832s. For this architecture, an interrupt cycle is outlined below.
•
The local CPU activates the STD bus interrupt request by
writing to the local control port. Please note that the STD bus
CPU must first remove the interrupt mask by writing to the STD
bus control port.
•
The STD bus CPU responds to the interrupt request by vectoring
to the dedicated interrupt service routine.
•
The interrupt service routine resets the interrupt request by
writing to the STD bus control port. To prevent missing a
subsequent interrupt, it is best to reset the request as early as
possible.
The ZT 8832 provides an Interrupt Status Port if it is necessary to
share the ZT 8832 interrupt with other STD bus boards, including
other ZT 8832s. The Interrupt Status Port, shown in Figure 3-4,
provides a means by which the STD bus CPU can determine, in
general, if any of the shared resources generated an interrupt request,
and specifically, if the ZT 8832 generated an interrupt request.
7
6
5
4
3
2
1
0
—
—
—
—
—
—
SS
LS
Register:Interrupt Status Port (ISP)
Address:38h
Access:Read
Local Interrupt Status
0 No interrupt
1 Interrupt
STD Bus Interrupt Status
0 No interrupt
1 Interrupt
Figure 3–4. Interrupt Status Port Architecture.
3-18
Theory of Operation
The local interrupt status bit (bit 0) indicates the status of the ZT 8832
interrupt request to the STD bus CPU. The STD bus interrupt status
bit (bit 1) indicates whether any of the interrupt sources sharing the
STD bus interrupt request with the ZT 8832 has an interrupt pending,
including the ZT 8832. The following steps outline an interrupt cycle
for a shared STD bus interrupt configuration:
1.
The local CPU activates the interrupt request by writing to the
local control port. Note that the STD bus CPU must first remove
the interrupt mask by writing to the STD bus control port.
2.
The STD bus CPU responds to the interrupt request by vectoring
to the interrupt service routine for the shared resources.
3.
The interrupt service routine reads the Interrupt Status Port to
determine if the ZT 8832 generated the request.
4.
If the local status bit of the Interrupt Status Port is active, then
the ZT 8832 has a request pending.
5.
If the local status bit is not active and the STD bus status bit is
active, then one of the other shared resources has an interrupt
pending. If other ZT 8832s share the interrupt, the Interrupt
Status Port of each one can be read to determine if a request is
pending. If the board select option is in use, each ZT 8832 must
be selected by writing the appropriate board address to the
Board Select Port before the Interrupt Status Port becomes
accessible.
6.
The interrupt service routine resets a ZT 8832 request by writing
to the STD bus control port. To prevent missing a subsequent
interrupt, it is best to reset the request as early as possible. If the
board select option is in use, the ZT 8832 must be selected
before the STD bus control port is accessible.
3-19
Theory of Operation
7.
3-20
This step applies only to systems with the STD bus CPU
configured for edge triggered as opposed to level triggered
interrupts. To avoid missing an interrupt request, the interrupt
service routine must continue servicing the shared interrupt
sources until the STD bus status bit of the ZT 8832 Interrupt
Status Port is inactive. This prevents the possibility of missing a
request because the edge occurred while servicing another
request. If there is more than one ZT 8832 sharing an interrupt
request, the STD bus status bit is redundant.
Theory of Operation
RESET
The ZT 8832 is reset by any of the following events:
•
Programming the STD bus control port with a 0Fh, followed by
a logical 0, from the STD bus CPU. This resets the ZT 8832
only. The STD bus is not affected.
•
Activating the pushbutton switch located on the ZT 8832. This
resets the ZT 8832 only. The STD bus is not affected.
•
Dropping Vcc applied to the ZT 8832 through pins 3 and 4 of
the STD bus connector to below a typical value of 4.37 V (worst
case specifications are 4.49 V maximum and 4.25 V minimum).
This resets the ZT 8832 only. The STD bus is not affected.
•
Failure to strobe the watchdog timer during stage 2 time delay.
This is an optional source of reset. If the two-stage watchdog
timer is enabled, it generates a non-maskable interrupt if it is not
strobed within the first-stage time out period. If the nonmaskable interrupt service routine does not strobe the watchdog
timer within the second-stage time out period, a local reset is
generated. This resets the ZT 8832 only. The STD bus is not
affected.
•
An active low on pin 47 (SYSRESET*) of the STD bus. The
STD bus CPU typically drives SYSRESET* to a logical 0 when
it is being reset. In response to a SYSRESET*, the ZT 8832
drives STD bus pin 48 (PBRESET*) to a logical 0 to prevent the
STD bus CPU from coming out of reset and attempting an
access to a ZT 8832 still in reset. An STD bus CPU is typically
held in reset by an active PBRESET*. In a system with multiple
ZT 8832s, PBRESET* is held active until the last ZT 8832 is
out of reset and operational.
In response to the STD bus control port reset, the ZT 8832 enters a
reset state for a variable time period. The ZT 8832 enters reset a
maximum of 250 ns after a 0Fh is written to the control port and
remains reset until a logical 0 is written to the control port. While it is
3-21
Theory of Operation
possible for the STD bus CPU to perform these writes as two
sequential operations, the SBX expansion module interface requires a
15 µs reset pulse width.
In response to all other reset sources, the ZT 8832 enters a reset state
that typically lasts 600 ms (worst-case specifications are 250 ms
minimum and 1000 ms maximum). The following events occur
during the reset period:
•
The STD bus control port and local control port are reset to a
logical 0 during power up, STD bus SYSRESET*, local
pushbutton reset, and watchdog timer stage 2 timeout.
•
If the Board Select Port is jumper enabled, the board is deselected during power-up. The Board Select Port is unaffected
by any other source of reset.
•
The dual port RAM controller is reset by all of the above
sources of reset. Data being transferred to or from the dual port
RAM at the time of reset will be corrupted. If the STD bus CPU
attempts a dual port RAM access while the controller is in reset,
it is held off until the reset period is complete. This will cause
problems in systems that have critical interrupt latencies, DMA
latencies, asynchronous data transfers, or dynamic RAM that
must be refreshed by the STD bus CPU.
3-22
Theory of Operation
Table 3-1 includes a list of devices affected by all sources of reset and
a page number for a detailed discussion on the reset state of each.
Table 3-1
Devices Affected by Reset.
Device
Page #
V40 CPU
V40 Configuration Registers
Counter/Timers
Interrupt Controller
DMA Controller
V40 Serial Port
82050 Serial Port
Parallel I/O
Watchdog Timer
5-23
6-12
7-14
8-19
9-17
10-11
11-20
12-6
13-5
3-23
Chapter 4
APPLICATION EXAMPLES
Contents
Page
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
EXAMPLE 1: V40 INITIALIZATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Program Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
EXAMPLE 2: PERIPHERAL INITIALIZATION . . . . . . . . . . . . . . . . . . . . 4-6
Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
Program Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
EXAMPLE 3: WATCHDOG TIMER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Program Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19
OVERVIEW
This chapter includes programming examples for initializing and
managing several devices found on the ZT 8832. In most cases, the
procedures will require some modification to meet the needs of
specific applications. Each example includes a discussion of program
objectives followed by an assembly language listing.
4-1
Application Examples
EXAMPLE 1: V40 INITIALIZATION
Objectives
The ZT 8832 is designed around the NEC 70208 (V40)
microprocessor. This high integration microprocessor includes
counter/timers, interrupt controller, DMA controller, serial controller,
and wait state generator, in addition to a CPU with an 8088
architecture. The V40 also includes programmable configuration
registers to provide flexibility when using these devices. Chapter 5
discusses the V40 configuration registers and the restrictions placed
on these registers by the ZT 8832. The following program code, taken
from the STD ROM software, initializes the V40 configuration
registers.
4-2
Application Examples
Program Code
;
EXAMPLE #1
PROGRAMMING ABSTRACT
;
;
;
;
Ziatech Corporation
San Luis Obispo, CA
06/01/89
; THIS PROGRAMMING EXAMPLE ILLUSTRATES THE CODE USED BY
; STD ROM TO INITIALIZE THE
; V40 CONFIGURATION REGISTERS.
;
SYSTEM EQUATES
RESV1
EQU
0FFFFH
; NEC RESERVED
; ON-CHIP PERIPHERAL CONNECTION REGISTER (OPCN)
OPCN
EQU
0FFFEH
; OPCN I/O ADDRESS
OPCN_INIT
EQU
00000110B
; SERIAL, IRQ2
; ON-CHIP PERIPHERAL SELECTION REGISTER (OPSEL)
OPSEL
EQU
0FFFDH
; OPSEL I/O ADDRESS
OPSEL_INIT
EQU
00001110B
; ENABLE SCU AND TCU
; ON-CHIP PERIPHERAL HIGH ORDER ADDRESS (OPHA)
OPHA
EQU
0FFFCH
; OPHA I/O ADDRESS
OPHA_INIT
EQU
0
; BOTTOM 256 BYTES
; DMA CONTROL UNIT
DULA
EQU
DULA_INIT
EQU
DCU
EQU
0FFFBH
; DULA I/O ADDRESS
0D0H
; DCU OFFSET ADDRESS
256*OPHA_INIT+DULA_INIT; DCU I/O ADDRESS
; INTERRUPT CONTROL UNIT
IULA
EQU
0FFFAH
; IULA I/O ADDRESS
IULA_INIT
EQU
20H
; ICU OFFSET ADDRESS
ICU
EQU
256*OPHA_INIT+IULA_INIT ; ICU I/O ADDRESS
; TIMER CONTROL UNIT
4-3
Application Examples
TULA
TULA_INIT
TCU
EQU
EQU
EQU
0FFF9H
; TULA I/O ADDRESS
40H
; TCU OFFSET ADDRESS
256*OPHA_INIT+TULA_INIT; TCU I/O ADDRESS
; SERIAL CONTROL UNIT
SULA
EQU
SULA_INIT
EQU
SCU
EQU
0FFF8H
; SULA I/O ADDRESS
0B0H
; SCU OFFSET ADDRESS
256*OPHA_INIT+SULA_INIT; SCU I/O ADDRESS
RESV2
0FFF7H
EQU
; NEC RESERVED
; WAIT REQUEST CONTROL UNIT
WCY2
EQU
0FFF6H
WCY2_INIT
EQU
00001000B
WCY1
EQU
0FFF5H
WCY1_INIT
EQU
10000000B
WMB
EQU
0FFF4H
WMB_INIT
EQU
0
;
;
;
;
;
;
RESV3
0FFF3H
; NEC RESERVED
; REFRESH CONTROL UNIT
RFC
EQU
RFC_INIT
EQU
0FFF2H
0
; RFC I/O ADDRESS
; DISABLE REFRESH
RESV4
0FFF1H
; NEC RESERVED
EQU
EQU
; TIMER AND CLOCK SELECTION
TCKS
EQU
0FFF0H
TCKS_INIT
EQU
0
WCY2 I/O ADDRESS
2 DMA WAIT STATES
WCY1 I/O ADDRESS
2 I/O WAIT STATES
WMB I/O ADDRESS
0 MEMORY WAIT STATES
; TCKS I/O ADDRESS
; INT CLOCK, DIV BY 2
;
MACRO DEFINITIONS
PUT
;
4-4
MACRO
MOV
MOV
OUT
ENDM
SRCE,DATA
DX,SRCE
AL,DATA
DX,AL
; I/O WRITE MACRO
Application Examples
STACK SEGMENT
STACK
STACK_TOP
STACK
DW
LABEL
SEGMENT
20 DUP (?)
WORD
ENDS
STACK
; UNINITIALIZED STACK
; TOP OF STACK
;
PROCEDURE
CODE
ASSUME
SEGMENT
PARA
CS:CODE, SS:STACK, DS:NOTHING, ES:NOTHING
MAIN:
MOV
MOV
MOV
CODE
PUT
PUT
PUT
PUT
PUT
PUT
PUT
PUT
PUT
PUT
PUT
PUT
ENDS
END
BX,SEG STACK
SS,BX
SP,OFFSET STACK_TOP
; INITIALIZE CONFIG REGS
OPCN,OPCN_INIT
OPSEL,OPSEL_INIT
OPHA,OPHA_INIT
DULA,DULA_INIT
IULA,IULA_INIT
TULA,TULA_INIT
SULA,SULA_INIT
WCY2,WCY2_INIT
WCY1,WCY1_INIT
WMB,WMB_INIT
RFC,RFC_INIT
TCKS,TCKS_INIT
MAIN
4-5
Application Examples
EXAMPLE 2: PERIPHERAL INITIALIZATION
Objectives
The ZT 8832 contains many of the most commonly used peripherals
found in STD bus applications. The following procedures show
example initialization sequences for the devices listed below. While
these procedures are general purpose in nature, they can be used as a
starting point for most application software.
•
Parallel Ports
•
Light Emitting Diode (LED)
•
82050 Serial Controller
•
V40 Serial Controller
•
V40 Interrupt Controller
•
V40 DMA Controller
Program Code
;
EXAMPLE #2
PROGRAMMING ABSTRACT
;
;
;
Ziatech Corporation
San Luis Obispo, CA
06/01/89
; THE FOLLOWING ARE EXAMPLE INITIALIZATION AND CONTROL PROCEDURES
; FOR SEVERAL OF THE PERIPHERAL DEVICES FOUND ON THE ZT 8832.
; WHILE THESE PROCEDURES ARE GENERAL PURPOSE IN NATURE, THEY CAN
; BE USED AS A STARTING POINT FOR APPLICATION SOFTWARE.
; PROCEDURES ARE INCLUDED FOR THE FOLLOWING DEVICES:
;
;
PARALLEL PORTS
;
LIGHT EMITTING DIODE (LED)
4-6
Application Examples
;
;
;
;
82050 SERIAL CONTROLLER
V40 SERIAL CONTROLLER AND BAUD RATE TIMER
V40 INTERRUPT CONTROLLER
V40 DMA CONTROLLER
;
SYSTEM EQUATES
; V40 CONFIGURATION REGISTERS
OPCN
EQU
0FFFEH
OPCN_INIT
EQU
00000010B
OPSEL
EQU
0FFFDH
OPSEL_INIT_S
EQU
00001000B
OPSEL_INIT_T
EQU
00000100B
OPSEL_INIT_I
EQU
00000010B
OPSEL_INIT_D
EQU
00000001B
OPHA
EQU
0FFFCH
OPHA_INIT
EQU
0
DULA
EQU
0FFFBH
DULA_INIT
EQU
0D0H
IULA
EQU
0FFFAH
IULA_INIT
EQU
20H
TULA
EQU
0FFF9H
TULA_INIT
EQU
40H
SULA
EQU
0FFF8H
SULA_INIT
EQU
0B0H
TCKS
EQU
0FFF0H
TCKS_INIT
EQU
0
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
OPCN I/O ADDRESS
EXTRN IRQS
OPSEL I/O ADDRESS
ENABLE SCU
ENABLE TCU
ENABLE ICU
ENABLE DCU
OPHA I/O ADDRESS
BOTTOM 256 BYTES
DULA I/O ADDRESS
DCU OFFSET ADDRESS
IULA I/O ADDRESS
ICU OFFSET ADDRESS
TULA I/O ADDRESS
TCU OFFSET ADDRESS
SULA I/O ADDRESS
SCU OFFSET ADDRESS
TCKS I/O ADDRESS
INT CLOCK, DIV BY 2
; PARALLEL PORT
PAR_PORT_0
PAR_PORT_1
PAR_PORT_2
PAR_PORT_INIT
EQU
EQU
EQU
EQU
200H
210H
220H
0
;
;
;
;
PARALLEL PORT 0 ADDRESS
PARALLEL PORT 1 ADDRESS
PARALLEL PORT 2 ADDRESS
INITIALIZE VALUE
; LED
PAR_PORT_LED
EQU
01000000B
; PARALLEL PORT LED CTRL
; 82050 ACC SERIAL CONTROLLER
ACC_PORT
EQU
03F8H
ACC_DIV1
EQU
ACC_PORT
ACC_DIV2
EQU
ACC_PORT+1
ACC_INTC
EQU
ACC_PORT+1
ACC_LINC
EQU
ACC_PORT+3
ACC_MODC
EQU
ACC_PORT+4
ACC_OUT2
EQU
00001000B
ACC_DLAB
EQU
10000000B
ACC_BAUD_LO
EQU
0CH
ACC_BAUD_HI
EQU
0
ACC_INTC_INIT
EQU
0
ACC_LINC_INIT
EQU
00000011B
ACC_MODC_INIT
EQU
00000011B
;
;
;
;
;
;
;
;
;
;
;
;
;
82050 ACC PORT ADDRESS
DIVISOR LSB
DIVISOR MSB
INTERRUPT CONTROL
LINE CONTROL
MODEM CONTROL
OUT2 BIT
DIVISOR LATCH SELECT
9600 BAUD
MASK INTERRUPTS
8 DATA, 0 PARITY, 1 STOP
ENABLE RTS AND DTR
4-7
Application Examples
; V40 SCU SERIAL CONTROLLER AND BAUD RATE TIMER
TCU_PORT
EQU
256*OPHA_INIT+TULA_INIT ; TCU I/O ADDRESS
TCU_TMR1
EQU
TCU_PORT+1
; TIMER 1 CONTROL
TCU_TMR1_BD1
EQU
26
; SCU BAUD OF 9600
TCU_TMR1_BD2
EQU
0
;
TCU_MODE
EQU
TCU_PORT+3
; TCU MODE ADDRESS
TCU_MODE_INIT
EQU
01110110B
; BIN, SQ, 2 BYTE, T1
SCU_PORT
EQU
256*OPHA_INIT+SULA_INIT ; SCU I/O ADDRESS
SCU_CMND
EQU
SCU_PORT+1
; COMMAND ADDRESS
SCU_CMND_INIT
EQU
00000101B
; ENABLE TXD AND RXD
SCU_MODE
EQU
SCU_PORT+2
; MODE ADDRESS
SCU_MODE_INIT
EQU
01001110B
; DIV BY 16, 8 BT, 0 PY, 1 SP
SCU_MASK
EQU
SCU_PORT+3
; MASK ADDRESS
SCU_MASK_INIT
EQU
00000011B
; MASK INTERRUPTS
; V40 INTERRUPT
ICU_PORT
ICU_IIW1
ICU_IIW1_INIT
ICU_IIW2
ICU_IIW2_INIT
ICU_IIW4
ICU_IIW4_INIT
ICU_MASK
ICU_MASK_INIT
CONTROLLER
EQU
256*OPHA_INIT+IULA_INIT ; ICU I/O ADDRESS
EQU
ICU_PORT+0
; INIT WORD 1 ADDRESS
EQU
00010011B
; EDGE TRIG, IIW4 ENABLE
EQU
ICU_PORT+1
; INIT WORD 2 ADDRESS
EQU
00001000B
; BASE VECTOR TYPE OF 8
EQU
ICU_PORT+1
; INIT WORD 4 ADDRESS
EQU
00000001B
; NORMAL NEST, FI COMMAND
EQU
ICU_PORT+1
; MASK ADDRESS
EQU
11111111B
; MASK COUNTER/TIMER 0
; MASK V40 SERIAL PORT
; MASK WATCHDOG TIMER
; MASK COUNTER/TIMER 1
; MASK SBX REQUEST 0
; MASK SBX REQUEST 1
; MASK 82050 SERIAL PORT
; MASK STD BUS CTRL PORT
; MASK FRONTPLANE J3-8
; MASK FRONTPLANE J3-10
; V40 DMA CONTROLLER
DCU_PORT
EQU
DCU_DICM
EQU
DCU_DICM_INIT
EQU
DCU_DCH
EQU
DCU_DCH_INIT
EQU
DCU_DBC
EQU
DCU_DBA_OFF
EQU
DCU_DBA_SEG
EQU
DCU_DDC
EQU
DCU_DDC_INIT
EQU
DCU_DMD
EQU
DCU_DMD_WRTE
EQU
DCU_DMD_READ
EQU
DCU_DMK
EQU
DCU_DMK_INIT
EQU
;
4-8
256*OPHA_INIT+DULA_INIT ; DCU I/O ADDRESS
DCU_PORT+0
; DICM ADDRESS
00000001B
; RESET DCU
DCU_PORT+1
; DCH ADDRESS
0
; CHANNEL 0
DCU_PORT+2
; DCU BASE COUNT
DCU_PORT+4
; DCU BASE ADDRESS
DCU_PORT+6
; OFFSET AND SEGMENT
DCU_PORT+8
; DCU DEVICE CONTROL
0
; ENABLE DMA
DCU_PORT+0AH
; DCU MODE
01000100B
; SNGL, INC, WRITE
01001000B
; SNGL, INC, READ
DCU_PORT+0FH
; DCU MASK
0EH
; NOT MASKED
Application Examples
MACRO DEFINITIONS
PUT
MACRO
MOV
MOV
OUT
ENDM
SRCE,DATA
DX,SRCE
AL,DATA
DX,AL
; I/O WRITE MACRO
;
STACK SEGMENT
STACK
STACK_TOP
STACK
DW
LABEL
SEGMENT
20 DUP (?)
WORD
ENDS
STACK
; UNINITIALIZED STACK
; TOP OF STACK
;
DATA SEGMENT
; THIS DATA SEGMENT PROVIDES A DATA BUFFER FOR DMA OPERATIONS
; BETWEEN THE SBX EXPANSION MODULE I/O AND LOCAL RAM.
DATA
DMA_BUF
DATA
CODE
ASSUME
DB
SEGMENT
256 DUP (?)
ENDS
; DMA DATA BUFFER
SEGMENT
PARA
CS:CODE, SS:STACK, DS:DATA, ES:NOTHING
MAIN:
MOV
MOV
MOV
MOV
MOV
BX,SEG STACK
SS,BX
SP,OFFSET STACK_TOP
BX,SEG DATA
DS,BX
;
4-9
Application Examples
PARALLEL PORT PROCEDURE
;
; THE ZT 8832 INCLUDES THREE PARALLEL PORTS. THE PARALLEL PORT
; OUTPUTS ARE ENABLED AND DISABLED WITH THE OUT2 BIT OF THE
; 82050 SERIAL PORT TO PREVENT GLITCHES DURING POWER-UP. THE
; POWER-UP STATE OF OUT2 IS A LOGICAL 0 THAT DISABLES THE
; PARALLEL PORT OUTPUTS. PASSIVE TERMINATION MAINTAINS A TTL
; HIGH ON THE PARALLEL I/O SIGNALS AT CONNECTOR J1 WHEN THE
; PARALLEL PORTS ARE DISABLED. BEFORE THE PARALLEL PORTS CAN
; BE USED, THE OUT2 BIT MUST BE PROGRAMMED. SINCE THE PARALLEL
; PORT BITS DO NOT POWER UP INITIALIZED, IT IS RECOMMENDED THAT
; THEY BE PROGRAMMED WITH A LOGICAL 0 BEFORE BEING ENABLED.
; THE PARALLEL PORTS ARE INVERTING, SO PROGRAMMING THEM WITH
; A LOGICAL 0 MAINTAINS THE TTL HIGH ON THE I/O SIGNALS AT
; CONNECTOR J1. THIS INITIALIZATION ALSO ENSURES THAT THERE
; IS NO CONTENTION BETWEEN THE PARALLEL PORT I/O SIGNALS THAT
; ARE DRIVEN AS INPUTS FROM EXTERNAL DEVICES. AFTER THIS
; INITIALIZATION SEQUENCE, THE APPLICATION SOFTWARE IS FREE TO
; COMMUNICATE WITH THE PARALLEL PORTS USING STANDARD INPUT
; AND OUTPUT INSTRUCTIONS, INCLUDING STRING INPUT AND OUTPUT.
;
; INPUTS:
NONE
; OUTPUTS:
PARALLEL PORTS ARE INITIALIZED AND ENABLED
; CALLS:
NONE
; DESTROYS:
FLAGS
PAR_INIT
PROC
; PRESERVE REGISTER STATUS
PUSH
AX
PUSH
DX
; INITIALIZE PARALLEL PORTS
PUT
PAR_PORT_0,PAR_PORT_INIT
PUT
PAR_PORT_1,PAR_PORT_INIT
PUT
PAR_PORT_2,PAR_PORT_INIT
; ENABLE PARALLEL PORTS
MOV
DX,ACC_MODC
IN
AL,DX
OR
AL,ACC_OUT2
OUT
DX,AL
; RESTORE REGISTER STATUS
POP
AX
POP
DX
PAR_INIT
ENDP
;
4-10
Application Examples
LED PROCEDURE
;
;
;
;
;
;
;
;
;
THE LED CAN BE TURNED ON AND OFF UNDER SOFTWARE CONTROL. THIS
IS A VALUABLE STATUS INDICATOR, ESPECIALLY DURING THE DEBUG
PHASE OF APPLICATION DEVELOPMENT. THE FOLLOWING CODE SHOWS
THE PROCEDURE FOR ARMING THE LED AND TURNING IT ON AND OFF.
INPUTS:
OUTPUTS:
CALLS:
DESTROYS:
LED_INIT
NONE
LED IS ARMED
NONE
FLAGS
PROC
; PRESERVE REGISTER STATUS
PUSH
PUSH
PUT
PUT
PUT
MOV
IN
OR
OUT
AX
DX
; ARM THE LED
PAR_PORT_0,PAR_PORT_INIT
PAR_PORT_1,PAR_PORT_INIT
PAR_PORT_2,PAR_PORT_INIT
DX,ACC_MODC
AL,DX
AL,ACC_OUT2
DX,AL
; RESTORE REGISTER STATUS
DX
AX
LED_INIT
POP
POP
ENDP
;
;
;
;
;
;
;
NONE
LED IS TURNED ON
NONE
FLAGS
ONCE THE LED IS ARMED, IT IS TURNED ON WITH THE FOLLOWING
PROCEDURE.
INPUTS:
OUTPUTS:
CALLS:
DESTROYS:
LED_ON
PROC
; PRESERVE REGISTER STATUS
PUSH
PUSH
MOV
IN
OR
OUT
LED_ON
POP
POP
ENDP
AX
DX
; TURN ON THE LED
DX,PAR_PORT_2
AL,DX
AL,PAR_PORT_LED
DX,AL
; RESTORE REGISTER STATUS
DX
AX
; ONCE THE LED IS ARMED AND TURNED ON, IT IS TURNED OFF WITH THE
; FOLLOWING PROCEDURE.
4-11
Application Examples
;
;
;
;
;
INPUTS:
OUTPUTS:
CALLS:
DESTROYS:
LED_OFF
NONE
LED IS TURNED OFF
NONE
FLAGS
PROC
; PRESERVE REGISTER STATUS
PUSH
PUSH
MOV
IN
AND
OUT
POP
POP
ENDP
LED_OFF
AX
DX
; TURN OFF THE LED
DX,PAR_PORT_2
AL,DX
AL,NOT PAR_PORT_LED
DX,AL
; RESTORE THE REGISTER STATUS
DX
AX
;
82050 SERIAL CONTROLLER PROCEDURE
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
THE 82050 SERIAL CONTROLLER IS A PC COMPATIBLE ASYNCHRONOUS
COMMUNICATION CHANNEL SUPPORTING JUMPER SELECTABLE DCE/DTE
AND RS-232/RS-485 CONFIGURATION. THIS PROCEDURE INITIALIZES
THE 82050 WITH THE FOLLOWING PARAMETERS:
BAUD RATE
DATA BITS
STOP BITS
PARITY
INTERRUPTS
9600
8
1
NONE
DISABLED
ONCE THE SERIAL PORT IS INITIALIZED AS SHOWN BELOW, IT IS
READY TO TRANSMIT AND RECEIVE CHARACTERS.
INPUTS:
OUTPUTS:
CALLS:
DESTROYS:
ACC_INIT
NONE
SERIAL PORT INITIALIZED
NONE
FLAGS
PROC
; PRESERVE REGISTER STATUS
PUSH
PUSH
PUT
PUT
PUT
PUT
4-12
AX
DX
; SET BAUD RATE
ACC_LINC,ACC_DLAB
ACC_DIV1,ACC_BAUD_LO
ACC_DIV2,ACC_BAUD_HI
; SET SERIAL CHARACTER ATTRIBUTES
ACC_LINC,ACC_LINC_INIT
; SET MODEM HANDSHAKE
Application Examples
PUT
PUT
ACC_INIT
POP
POP
ENDP
ACC_MODC,ACC_MODC_INIT
; MASK INTERRUPTS
ACC_INTC,ACC_INTC_INIT
; RESTORE REGISTER CONTENTS
DX
AX
;
V40 SERIAL CONTROLLER PROCEDURE
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
THE V40 SERIAL CONTROLLER IS AN 8251 COMPATIBLE ASYNCHRONOUS
COMMUNICATION CHANNEL CONFIGURED AS THREE-WIRE (TRANSMIT
DATA, RECEIVE DATA, AND GROUND) RS-232 DTE. THE PROCEDURE
SHOWN BELOW INITIALIZES THE V40 SCU WITH THE FOLLOWING
PARAMETERS:
SCU AND TCU ENABLED
SCU BASE ADDRESS OF 00B0H
TCU BASE ADDRESS OF 0040H
BAUD RATE
9600
DATA BITS
8
STOP BITS
1
PARITY
NONE
INTERRUPTS
DISABLED
ONCE THE SERIAL PORT IS INITIALIZED AS SHOWN BELOW, IT IS
READY TO TRANSMIT AND RECEIVE CHARACTERS.
INPUTS:
OUTPUTS:
CALLS:
DESTROYS:
SCU_INIT
NONE
SERIAL PORT INITIALIZED
NONE
FLAGS
PROC
; PRESERVE REGISTER STATUS
PUSH
PUSH
PUT
PUT
PUT
PUT
PUT
PUT
PUT
PUT
PUT
PUT
AX
DX
; INITIALIZE V40 CONFIG REGS
OPCN,OPCN_INIT
OPSEL,OPSEL_INIT_S+OPSEL_INIT_T
OPHA,OPHA_INIT
TULA,TULA_INIT
SULA,SULA_INIT
TCKS,TCKS_INIT
; SET BAUD RATE
TCU_MODE,TCU_MODE_INIT
TCU_TMR1,TCU_TMR1_BD1
TCU_TMR1,TCU_TMR1_BD2
; SET SERIAL CHARACTER ATTRIBUTES
SCU_MODE,SCU_MODE_INIT
; ENABLE TXD AND RXD
4-13
Application Examples
PUT
PUT
SCU_INIT
POP
POP
ENDP
SCU_CMND,SCU_CMND_INIT
; MASK INTERRUPTS
SCU_MASK,SCU_MASK_INIT
; RESTORE REGISTER STATUS
DX
AX
;
V40 INTERRUPT CONTROLLER PROCEDURE
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
THE V40 INTERRUPT CONTROLLER IS USED TO SERVICE ASYNCHRONOUS
EVENTS SUCH AS A COUNTER/TIMER TIMEOUT, DATA TRANSFERS
THROUGH A SERIAL LINK, AND DATA TRANSFERS THROUGH DUAL PORT
RAM. THE EXAMPLE CODE IS A GENERAL PURPOSE INITIALIZATION
PROCEDURE THAT PROGRAMS THE FOLLOWING:
ICU ENABLED
BASE ADDRESS OF 0020H
EDGE TRIGGERED
BASE VECTOR OF TYPE 8
NORMAL NESTING
FI COMMAND
MASK ALL INPUTS
IN ADDITION TO THE INITIALIZATION PROCEDURE PROVIDED BELOW,
THE APPLICATION SOFTWARE MUST DEVELOP THE NECESSARY INTERRUPT
SERVICE ROUTINES, STORE THE ADDRESS OF THE INTERRUPT SERVICE
ROUTINES AT THE APPROPRIATE TYPE ADDRESS, UNMASK THE SUPPORTED
REQUESTS THROUGH THE ICU MASK REGISTER, AND ENABLE V40
INTERRUPTS WITH THE ENABLE INTERRUPT INSTRUCTION. AFTER THESE
STEPS ARE COMPLETE, THE INTERRUPTING PERIPHERALS WILL BE
SERVICED ON DEMAND.
INPUTS:
OUTPUTS:
CALLS:
DESTROYS:
ICU_INIT
NONE
INTERRUPT CONTROLLER INITIALIZED
NONE
FLAGS
PROC
; PRESERVE REGISTER CONTENTS
PUSH
PUSH
PUT
PUT
PUT
PUT
PUT
PUT
PUT
4-14
AX
DX
; INITIALIZE V40 CONFIG REGS
OPCN,OPCN_INIT
OPSEL,OPSEL_INIT_I
OPHA,OPHA_INIT
IULA,IULA_INIT
; INITIALIZE PIC
ICU_IIW1,ICU_IIW1_INIT
ICU_IIW2,ICU_IIW2_INIT
ICU_IIW4,ICU_IIW4_INIT
Application Examples
PUT
ICU_INIT
POP
POP
ENDP
ICU_MASK,ICU_MASK_INIT
; RESTORE THE REGISTER STATUS
DX
AX
;
V40 DMA CONTROLLER PROCEDURE
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
;
THE V40 DMA CONTROLLER IS USED FOR HIGH SPEED DATA TRANSFERS
BETWEEN AN SBX EXPANSION MODULE THAT SUPPORTS DMA AND EITHER
DUAL PORT OR LOCAL RAM. THE APPROXIMATE DATA RATE FOR TRANSFERS BETWEEN THE EXPANSION MODULE AND RAM USING STANDARD INPUT
AND OUTPUT INSTRUCTIONS IS 235 KBYTES PER SECOND. USING DMA,
THE TRANSFER RATE IS INCREASED TO APPROXIMATELY 1.3 MBYTES PER
SECOND, FOR A PERFORMANCE INCREASE OF OVER 80 PERCENT. THE
FIRST PROCEDURE IS A GENERAL PURPOSE INITIALIZATION ROUTINE
THAT PROGRAMS THE FOLLOWING:
DCU ENABLED
BASE ADDRESS OF 00D0H
DMA ENABLED
INPUTS:
OUTPUTS:
CALLS:
DESTROYS:
DCU_INIT
NONE
DMA CONTROLLER INITIALIZED
NONE
FLAGS
PROC
; PRESERVE REGISTER CONTENTS
PUSH
PUSH
PUT
PUT
PUT
PUT
PUT
PUT
AX
DX
; INITIALIZE V40 CONFIG REGS
OPSEL,OPSEL_INIT_D
OPHA,OPHA_INIT
DULA,DULA_INIT
; INITIALIZE DMA CONTROLLER
DCU_DICM,DCU_DICM_INIT
DCU_DCH,DCU_DCH_INIT
DCU_DDC,DCU_DDC_INIT
; RESTORE THE REGISTER STATUS
DCU_INIT
POP
POP
ENDP
DX
AX
; ONCE THE DMA CONTROLLER IS INITIALIZED, IT IS PROGRAMMED FOR
; DMA WRITE TRANSFERS WITH THE FOLLOWING PROCEDURE. A DMA
; WRITE DEFINES THE SBX I/O AS THE DATA SOURCE AND THE RAM
; MEMORY AS THE DESTINATION. NOTE THAT EITHER DUAL PORT OR
; LOCAL RAM MAY BE USED AS RAM MEMORY. THE FOLLOWING
; PARAMETERS ARE SELECTED:
4-15
Application Examples
;
;
;
;
;
;
;
;
;
SINGLE BYTE TRANSFERS
INCREMENT MEMORY ADDRESS
SBX I/O TO RAM OPERATION
INPUTS:
OUTPUTS:
CALLS:
DESTROYS:
DCU_WRITE
NONE
SBX I/O TO RAM MEMORY TRANSFERS ARMED
NONE
FLAGS
PROC
; PRESERVE REGISTER STATUS
PUSH
PUSH
PUSH
PUSH
MOV
MOV
MOV
MOV
SHL
SHR
ADD
ADC
MOV
MOV
OUT
MOV
MOV
OUT
MOV
MOV
OUT
PUT
PUT
DCU_WRITE
POP
POP
POP
POP
ENDP
AX
BX
CX
DX
; SET UP ADDRESS REGISTERS
AX,SEG DATA
DX,OFFSET DMA_BUF
BL,AH
CL,4
AX,CL
BL,CL
DX,AX
BL,0
AX,DX
DX,DCU_DBA_OFF
DX,AX
AX,BX
DX,DCU_DBA_SEG
DX,AL
; SET UP COUNT REGISTERS
AX,SIZE DMA_BUF-1
DX,DCU_DBC
DX,AX
; SET UP MODE AND ENABLE
DCU_DMD,DCU_DMD_WRTE
DCU_DMK,DCU_DMK_INIT
; RESTORE REGISTER STATUS
DX
CX
BX
AX
; ONCE THE DMA CONTROLLER IS INITIALIZED, IT IS PROGRAMMED FOR
; DMA READ TRANSFERS WITH THE FOLLOWING PROCEDURE. A DMA
; READ DEFINES THE RAM MEMORY AS THE DATA SOURCE AND THE SBX
; I/O AS THE DESTINATION. NOTE THAT EITHER DUAL PORT OR LOCAL
; RAM MAY BE USED AS RAM MEMORY. THE FOLLOWING PARAMETERS ARE
; SELECTED:
;
;
SINGLE BYTE TRANSFERS
;
INCREMENT MEMORY ADDRESS
;
RAM TO SBX I/O OPERATION
;
; INPUTS:
NONE
; OUTPUTS:
RAM MEMORY TO SBX I/O TRANSFERS ARMED
4-16
Application Examples
; CALLS:
; DESTROYS:
NONE
FLAGS
DCU_READ
PROC
; PRESERVE REGISTER STATUS
PUSH
PUSH
PUSH
PUSH
MOV
MOV
MOV
MOV
SHL
SHR
ADD
ADC
MOV
MOV
OUT
MOV
MOV
OUT
MOV
MOV
OUT
PUT
PUT
POP
POP
POP
POP
DCU_READ
CODE
POP
POP
POP
ENDP
ENDS
END
AX
BX
CX
DX
; SET UP ADDRESS REGISTERS
AX,SEG DATA
DX,OFFSET DMA_BUF
BL,AH
CL,4
AX,CL
BL,CL
DX,AX
BL,0
DX,DCU_DBA_OFF
AX,DX
DX,AX
DX,DCU_DBA_SEG
AX,BX
DX,AL
; SET UP COUNT REGISTERS
AX,SIZE DMA_BUF
DX,DCU_DBC
DX,AX
; SET UP MODE AND ENABLE
DCU_DMD,DCU_DMD_READ
DCU_DMK,DCU_DMK_INIT
; RESTORE REGISTER STATUS
DX
CX
BX
AX
; RESTORE REGISTER STATUS
DX
CX
AX
MAIN
4-17
Application Examples
EXAMPLE 3: WATCHDOG TIMER
Objectives
A watchdog timer is useful in applications in which a microprocessor
controls a physical process that may be damaged if the
microprocessor fails to function as programmed. The ZT 8832
includes a jumper selectable watchdog timer which monitors
operation of the V40 and initiates corrective action if necessary.
As discussed in Chapter 13, the watchdog timer has two stages. In
normal operation, the application software strobes the watchdog timer
at a periodic rate less than the stage 1 timeout. If this strobe does not
take place, it is because the V40 is not operating as programmed. If
this happens, stage 1 times out and generates a non-maskable
interrupt.
The service routine designed to handle the non-maskable interrupt is
application specific. This example simply sets a flag in battery-backed
RAM to indicate the system failure, and loops until the stage 2
timeout resets the ZT 8832. While not implemented in this example,
the reset can be prevented by the non-maskable interrupt service
routine strobing the watchdog timer before the stage 2 timeout.
4-18
Application Examples
Program Code
;
EXAMPLE #3
PROGRAMMING ABSTRACT
;
;
;
Ziatech Corporation
San Luis Obispo, CA
06/01/89
; THIS PROGRAMMING EXAMPLE ILLUSTRATES THE CODE USED TO ARM AND
; STROBE THE WATCHDOG TIMER. ALSO INCLUDED IS A NON-MASKABLE
; INTERRUPT SERVICE ROUTINE THAT FLAGS A WATCHDOG TIMEOUT IN
; DUAL PORT RAM. NOT SHOWN IS THE ZT 8832 STARTUP CODE THAT
; TESTS THE FLAG LOCATION TO SEE WHETHER THE RESET WAS CAUSED
; BY A WATCHDOG TIMEOUT OR BY ANOTHER SOURCE OF RESET.
;
SYSTEM EQUATES
; 82050 SERIAL PORT
SER_PORT
EQU
SER_PORT_CTRL
EQU
SER_PORT_OUT2
EQU
03F8H
SER_PORT+4
00001000B
; 82050 BASE PORT
; MODEM CONTROL PORT
; OUT2 BIT USED FOR
; PARALLEL PORT OUTPUT
; ENABLE
200H
210H
220H
0
10000000B
;
;
;
;
;
; PARALLEL PORT
PAR_PORT_0
PAR_PORT_1
PAR_PORT_2
PAR_PORT_INIT
PAR_PORT_WD
EQU
EQU
EQU
EQU
EQU
PARALLEL PORT 0 ADDRESS
PARALLEL PORT 1 ADDRESS
PARALLEL PORT 2 ADDRESS
INITIALIZE VALUE
WATCHDOG STROBE BIT
;
4-19
Application Examples
STACK SEGMENT
STACK
STACK_TOP
STACK
DW
LABEL
SEGMENT
20 DUP (?)
WORD
ENDS
STACK
; UNINITIALIZED STACK
; TOP OF STACK
;
DATA SEGMENT
; A MULTIPLE CHARACTER FLAG IS USED TO REDUCE THE CHANCE THAT
; THE ZT 8832 STARTUP CODE (NOT SHOWN HERE) WILL FALSELY DETECT
; A WATCHDOG TIMER RESET AFTER A POWER CYCLE.
DATA
WATCHDOG_FLAG
DATA
DB
SEGMENT
’WATCHDOG TIMEOUT’ ; WATCHDOG FLAG MESSAGE
ENDS
;
DUALPORT SEGMENT
; THE DUAL PORT RAM IS MAPPED AT 8000H IN THE LOCAL CPU MEMORY
; ADDRESS SPACE.
DUALPORT
WATCHDOG_STAT
DUALPORT
DB
SEGMENT AT 8000H
16 DUP (?)
; DUAL PORT WATCHDOG FLAG
ENDS
;
INTERRUPT POINTERS SEGMENT
INT_POINT
TYPE_0
4-20
ORG
DD
SEGMENT AT 0
0
?
; DIV BY ZERO (NOT USED)
Application Examples
TYPE_1
TYPE_2
INT_POINT
DD
DD
ENDS
?
?
; SINGLE STEP (NOT USED)
; NON-MASKABLE INTERRUPT
PROCEDURES
CODE
ASSUME
;
;
;
;
;
;
;
;
;
;
;
;
;
;
SEGMENT
PARA
CS:CODE, SS:STACK, DS:DATA, ES:DUALPORT
THE WATCHDOG TIMER GENERATES A NON-MASKABLE INTERRUPT IF ARMED
AND ALLOWED TO TIME OUT. THE TASKS PERFORMED BY THE SERVICE
ROUTINE ARE VERY APPLICATION SPECIFIC. THIS EXAMPLE SIMPLY
SETS A FLAG IN DUAL PORT RAM AND LOOPS UNTIL RESET. SINCE THE
SERVICE ROUTINE DOES NOT STROBE THE WATCHDOG TIMER, THE
SECOND STAGE WILL TIME OUT AND GENERATE A LOCAL RESET. THE
ZT 8832 STARTUP CODE (NOT SHOWN HERE) CAN TEST THE WATCHDOG
FLAG TO DETERMINE WHETHER OR NOT A WATCHDOG TIMEOUT HAS
OCCURED, AND CAN THEN TAKE THE NECESSARY ACTION.
INPUTS:
OUTPUTS:
CALLS:
DESTROYS:
NON-MASKABLE INTERRUPT REQUEST
WATCHDOG_FLAG SET
NONE
ALL
WATCHDOG_NMI
;LP1:
MOV
MOV
MOV
MOV
MOV
MOV
CLD
MOV
REP MOVSB
JMP
PROC
AX,SEG DATA
DS,AX
SI,OFFSET WATCHDOG_FLAG
AX,SEG DUALPORT
ES,AX
DI,OFFSET WATCHDOG_STAT
CX,16
LP1
WATCHDOG_NMI
ENDP
;
;
;
;
;
;
;
;
;
ASSUMES THE PARALLEL PORTS ARE ENABLED
STROBES THE WATCHDOG TIMER
NONE
FLAGS
THE FOLLOWING PROCEDURE STROBES THE WATCHDOG TIMER. THIS
PROCEDURE MUST BE CALLED BY THE MAIN PROCEDURE AT A PERIODIC
RATE LESS THAN THE STAGE 1 DELAY OF THE WATCHDOG TIMER. THE
DEFAULT STAGE 1 DELAY IS 60 MILLISECONDS MINIMUM.
INPUTS:
OUTPUTS:
CALLS:
DESTROYS:
WATCHDOG_STB
PROC
PUSH
PUSH
MOV
IN
AX
DX
DX,PAR_PORT_2
AL,DX
; PRESERVE REGISTER STATUS
; WRITE WATCHDOG BIT LOW
4-21
Application Examples
WATCHDOG_STB
AND
OUT
OR
OUT
POP
POP
RET
ENDP
AL, NOT PAR_PORT_WD
DX,AL
AL,PAR_PORT_WD ; WRITE WATCHDOG BIT HIGH
DX,AL
DX
; RESTORE REGISTER STATUS
AX
; EXIT
;
;
;
;
;
;
;
;
;
;
;
;
;
;
NONE
NONE
WATCHDOG_STB
ALL
THE MAIN PROCEDURE INCLUDES A LOOP AND A CALL TO THE WATCHDOG
STROBE PROCEDURE. THE LOOP REPRESENTS THE APPLICATION SOFTWARE. IN NORMAL OPERATION, THE WATCHDOG STROBE PROCEDURE IS
CALLED AT A PERIODIC RATE LESS THAN THE WATCHDOG TIMER STAGE
1 DELAY OF 60 MILLISECONDS. A LOOP COUNT OF 6000H IS SHORT
ENOUGH TO PREVENT THE TIMEOUT. IF ANYTHING PREVENTS THE
APPLICATION SOFTWARE FROM CALLING THE WATCHDOG STROBE PROCEDURE
IN TIME, STAGE 1 TIMES OUT AND THE NMI SERVICE ROUTINE IS INVOKED.
THIS CAN BE SEEN BY CHANGING THE LOOP COUNT TO 8000H.
INPUTS:
OUTPUTS:
CALLS:
DESTROYS:
MAIN:
MOV
MOV
MOV
MOV
MOV
ASSUME
CS:CODE, SS:STACK, DS:INT_POINT, ES:DUALPORT
PUSH
MOV
MOV
MOV
MOV
POP
ASSUME
LP2:
4-22
BX, SEG DATA
; INITIALIZE SEGMENTATION
DX,BX
BX, SEG STACK
SS,BX
SP,OFFSET STACK_TOP
DS
; INITIALIZE INT VECTOR
BX, SEG INT_POINT
DS,BX
WORD PTR TYPE_2,OFFSET WATCHDOG_NMI
WORD PTR TYPE_2+2,SEG CODE
DS
CS:CODE, SS:STACK, DS:DATA, ES:DUALPORT
MOV
MOV
OUT
MOV
OUT
MOV
OUT
MOV
IN
OR
OUT
MOV
IN
OR
OUT
MOV
AL,PAR_PORT_INIT;
DX,PAR_PORT_0
;
DX,AL
;
DX,PAR_PORT_1
;
DX,AL
;
DX,PAR_PORT_2
DX,AL
DX,SER_PORT_CTRL;
AL,DX
AL,SER_PORT_OUT2
DX,AL
DX,PAR_PORT_2
;
AL,DX
AL,PAR_PORT_WD
DX,AL
CX,6000H
;
INITIALIZE PARALLEL I/O
SO THE J1 CONNECTOR
OUTPUTS DO NOT CHANGE
WHEN PARALLEL PORTS ARE
ENABLED
ENABLE PARALLEL I/O
ARM WATCHDOG TIMER
SIMULATED PROGRAM LOOP
Application Examples
LP3:
CODE
LOOP
CALL
JMP
ENDS
END
LP3
WATCHDOG_STB
LP2
; STROBE WATCHDOG TIMER
; REPEAT
MAIN
4-23
Chapter 5
PROCESSOR DESCRIPTION (V40)
Contents
Page
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
ZT 8832 SPECIFICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
COMMONLY ASKED QUESTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
FUNCTIONAL BLOCKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
CPU - Central Processing Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
BIU - Bus Interface Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19
BAU - Bus Arbitration Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19
CGU - Clock Generator Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20
VCR - V40 Configuration Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20
WCU - Wait Control Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21
SCU - Serial Control Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21
TCU - Counter/Timer Control Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21
ICU - Interrupt Control Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
DCU - DMA Control Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23
MEMORY AND I/O ADDRESSING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-24
INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-27
Divide Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-31
Single-Step . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-31
Non-Maskable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-32
Fixed Vector Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-32
Overflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-32
Check Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-33
Variable Vector Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-33
Emulation Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-33
8080 EMULATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-34
5-1
Processor Description (V40)
OVERVIEW
The NEC 70208, commonly known as the V40, is a CMOS microprocessor with a 16-bit internal and 8-bit external data bus structure.
The V40 instruction set includes all of the instructions of the 8088 and
80188 microprocessors, plus a few more. The added instructions
include string I/O, expanded rotate and shift, bit and nibble
manipulation, BCD arithmetic, and 8080 emulation mode.
The V40 contains several peripherals frequently used in STD bus
applications. These peripherals include a serial controller, interrupt
controller, direct memory access (DMA) controller, counter/timers,
and a programmable wait-state generator.
This chapter divides the V40 microprocessor into functional blocks
and presents an overview of each. More detailed descriptions of the
programmable functional blocks are found in subsequent chapters.
ZT 8832 SPECIFICS
The V40 includes a dynamic RAM (DRAM) refresh controller for
applications supporting DRAM devices. Since the ZT 8832 contains
only static RAM, the refresh controller is not needed.
The V40 includes four DMA channels. The ZT 8832 makes use of
one of these channels to provide high speed data transfers between I/O
on the SBX expansion module and dual port or local RAM. The
remaining three channels are not supported by the ZT 8832.
5-2
Processor Description (V40)
COMMONLY ASKED QUESTIONS
1.
Is the V40 pin-compatible with the 80188?
The V40 and 80188 are not pin-compatible. This means an
80188 cannot be plugged into the V40 socket. This is unlike the
V20 and V30, which are interchangeable with the 8088 and
8086, respectively.
2.
What are the hardware differences between the V40 and the
80188?
One of the most notable differences is that the V40 is fabricated
with a CMOS process. CMOS technology provides an increase
in both temperature range and noise immunity, with a reduction
in power consumption. The CMOS V40 has a maximum power
dissipation of less than 1/2 W and a standby dissipation of less
than 1/10 W. The 80188 has a maximum power dissipation of
3 W; that is, too hot to touch.
Other differences are as follows: the V40 includes an asynchronous serial port; the V40 interrupt controller and counter/timers
have the same architecture as the interrupt controller and
counter/timers used in the Personal Computer; and the data
transfer rate for the V40 DMA controller is twice as fast.
3.
Is the V40 software compatible with the 8088 and 80188
microprocessors?
Yes. The V40 instruction set is 100% object code compatible
with the 80188 instruction set. This means that a program
written for the 8088 or 80188 will execute on the V40.
Application software using the peripherals internal to the 80188
requires some modification.
4.
What are the V40 instructions not in the 8088 or 80188 and
how are they used?
The V40 instruction set is a superset of the 8088 and 80188.
This means the V40 includes all of the instructions found in
5-3
Processor Description (V40)
these microprocessors, plus a few more. The added instructions
are outlined below.
The following instructions are useful in testing and setting status
bits for I/O operations and in bit manipulation for graphics
applications.
INS
EXT
TEST1
SET1
CLR1
NOT1
Insert bit field
Extract bit field
Test bit
Set bit
Clear bit
Complement bit
The instructions shown below are useful for manipulating binary
numbers in a decimal format.
ADD4S
SUB4S
CMP4S
ROL4
ROR4
BCD string addition
BCD string subtraction
BCD string comparison
Rotate BCD digit left
Rotate BCD digit right
The string I/O instructions shown below can be combined with
the repeat prefixes for high speed data transfers between I/O and
memory.
INM
OUTM
String input
String output
Other instructions not found in the 80188 instruction set are
listed below.
REPC
REPNC
FPO2
BRKEM
RETEM
5-4
Repeat while carry set
Repeat while carry cleared
Floating point operation 2
Break for emulation mode
Return from emulation mode
Processor Description (V40)
FUNCTIONAL BLOCKS
The V40 can be divided into the major functional blocks listed below
and shown in Figure 5-1 on page 5-6.
CPU
Central Processing Unit
BIU
Bus Interface Unit
BAU
Bus Arbitration Unit
CGU
Clock Generator Unit
VCR
V40 Configuration Registers
WCU Wait Control Unit
SCU
Serial Control Unit
TCU
Counter/Timer Control Unit
ICU
Interrupt Control Unit
DCU
DMA Control Unit
5-5
Processor Description (V40)
CPU - Central Processing Unit
The architecture of the CPU functional block is compatible with the
8088. The CPU recognizes all of the instructions found in the 8088
and 80188 microprocessors. Figure 5-2 shows a block diagram of the
CPU divided into two elements: the Bus Control Unit (BCU) and the
Execution Unit (EXU). The BCU prefetches instructions and data into
a 4-byte instruction queue. The EXU executes the instructions. This
pipelined architecture increases the throughput over the typical
microprocessor that must wait for an instruction or operand to be
fetched before operation is continued.
TOUT2
TCTL2
TCLK
TCU
A16/PS0A19/PS3
WCU
A8-15
AD0-7
IRQ1-7
ICU
VCR
BIU
TxD
RxD
SCU
BS0-2
QS0-1
ASTB
READY
RESOUT
BUFR/W
POLL
MWR
MRD
IOWR
IORD
BUFEN
RESET
CPU
DMARQ
DMAACK
DCU
BAU
HLDAK
HLDRQ
NMI
INTAK
X1
X2
CLKOUT
CGU
Figure 5–1. V40 Block Diagram.
5-6
Processor Description (V40)
Internal address/data bus (20)
TO BIU
ADM
BCU
PS [CS]
SS [SS]
DS0 [DS]
DS1 [ES]
PFP [IP]
DP
Q0-Q3
AW [AX]
BW[BX]
CW [CX]
DW [DX]
SP [SP]
BP [BP]
IX [SI]
IY [DI]
PC
LC
EXU
TA, TB, AND TC
ALU
PSW [FL]
Effective Address
Generator
Subdata bus (16)
Main data bus (16)
Figure 5–2. CPU Block Diagram.
5-7
Processor Description (V40)
CPU Functional Blocks
The functional blocks in Figure 5-2 are described below. The NEC
mnemonic is shown for each block, followed by the Intel mnemonic
in brackets. For example, the CPU flag register is represented by
PSW [FL] because NEC labels it Processor Status Word and Intel
labels it Flags.
Segment Registers
PS [CS], SS [SS], DS0 [DS], and DS1 [ES]
The CPU can address up to 1 Mbyte of memory in segments of
64 Kbytes or less. The starting address of a segment is specified
in a segment register. The four segment registers are as follows:
PS [CS] SS [SS] DS0 [DS] DS1 [ES] -
Program Segment register
Stack Segment register
Data Segment register 0
Data Segment register 1
All memory addresses are specified with a segment and offset as
shown in Table 5-1. The segment and offset used depend on the
type of instruction being executed.
The program always resides in a program segment pointed to by
the PS [CS] register. The PFP [IP] always contains the offset
within the program segment. The program stack always resides in
the stack segment pointed to by the SS [SS] register. The SP [SP]
contains the offset of the top of the stack. Stack variables can be
addressed using the BP [BP] register because the default segment
register is SS [SS].
Program variables generally reside in the data segment with the
segment address in the DS0 [DS] register. The offset of the
variable within DS0 [DS] is called the effective address. The
EXU calculates the effective address by summing any
combination of displacement, base register, and index register.
The possible combinations of offset, base, and index provide the
programmer with a large variety of addressing modes.
5-8
Processor Description (V40)
Strings are addressed differently from other variables. The
segment register used to point to the source string is DS0 [DS],
unless an override is used. The offset for the string source is the
IX [SI] register. The segment register for the string destination is
always DS1 [ES] and the offset is specified in IY [DI].
Table 5-1
Segment Registers.
Memory
Reference
Default
Segment
Alternate
Segment
Instruction Fetch
PS[CS]
NONE
PFP[IP]
Stack Operation
SS[SS]
NONE
SP[SP]
Variable (except
following)
DS0[DS]
PS[CS], DS1[ES],
SS[SS]
Effective
Address
String Source
DS0[DS]
PS[CS], DS1[ES],
SS[SS]
IX[SI]
String Destination
DS1[ES]
NONE
IY[DI]
BP[BP] Used As
Base Register
SS[SS]
PS[CS], DS0[DS],
DS1[ES]
Effective
Address
BW[BX] Used As
Base Register
DS0[DS]
PS[CS], DS1[ES],
SS[SS]
Effective
Address
Offset
Prefetch Pointer
PFP [IP]
The prefetch pointer PFP [IP] is a 16-bit binary counter that
maintains the offset of the next instruction to be fetched into the
instruction queue. The BCU fetches a program instruction based
on the segment value in the PS [CS] register and the offset in the
PFP [IP].
5-9
Processor Description (V40)
For sequentially addressed instructions, the PFP [IP] is incremented by the number of bytes of the current instruction to point to
the next. For program branching, such as intrasegment and
intersegment jumps, the PFP [IP] is programmed with a value
contained within the jump instruction. The PFP [IP] is not
accessible to the programmer.
Data Pointer
DP
This 16-bit register is the destination for the offset address
calculated by the effective address generator. The offset address
calculation is done by hardware instead of the traditional
microcode, saving three to ten clock cycles for every calculation.
The DP register is not accessible to the programmer.
Instruction Queue
Q0 - Q3
The instruction queue is a temporary storage location for program
instructions and variables that have been fetched by the BCU to
be executed by the EXU. The instruction queue consists of four
8-bit registers, Q0 through Q3. These registers allow instruction
fetching by the BCU and instruction execution by the EXU to be
independent operations. This overlap essentially eliminates the
time required to fetch program instructions and data. Q0 through
Q3 are not accessible to the programmer.
Address Modifier
ADM
The V40 uses a 20-bit memory address to access any location in
the 1 Mbyte addressing range. The 20-bit memory address is the
sum of a segment (shifted left four bits) and an offset. The offset
is taken from the PFP [IP] if a program instruction is being
addressed or from the DP for all other data. The ADM does this
addition. If the PFP [IP] was used, the ADM increments it for the
next instruction. The ADM is not accessible to the programmer.
5-10
Processor Description (V40)
General Purpose Registers
AW [AX], BW [BX], CW [CX], and DW [DX]
The CPU has four 16-bit general purpose registers. Each of these
registers can be addressed as one 16-bit register or two 8-bit
registers. The 16-bit registers are referred to as AW [AX], BW
[BX], CW [CX], and DW [DX]. The high order bytes of the 16bit registers are AH, BH, CH, and DH, while the low order bytes
are AL, BL, CL, and DL. The most common use of these
registers is to provide a temporary storage location for data. Some
instructions do assign specific meanings to the general purpose
registers, as shown in Table 5-2.
Table 5-2
Implied Use of General Registers.
Register
Implied Use
Register
Implied Use
AW [AX]:
Word Multiplication/
Division
Word Input/Output
BW [BX]:
Translation
CW [CX]:
String Operations
Byte Multiplication/
Division
Byte Input/Output
Translation
BCD and Decimal
Arithmetic
CL:
Variable Shift
and Rotate
DW [DX]:
Word Multiplication/
Division
Indirect Input/Output
AL:
AH:
Byte Multiplication/
Division
5-11
Processor Description (V40)
Pointers and Index Registers
SP [SP], BP [BP], and IX [SI], IY [DI]
The two 16-bit pointer registers are used primarily for stack
operations. The Stack Pointer (SP [SP]) is the offset to the top of
the stack within the stack segment. This pointer is adjusted
automatically each time a stack operation is performed. The Base
Pointer (BP [BP]) is an offset to any location within the stack
segment. The BP [BP] is useful as a pointer to variables being
passed on the stack. Both pointer registers are accessible to the
programmer.
The 16-bit index registers are used primarily for string operations.
Strings are linear arrays of data that can be organized as words,
bytes, nibbles, or even as bit values. The index registers specify
the offset of the string source (IX [SI]) and destination (IY [DI])
within Data Segment 0 (DS0 [DS]) and Data Segment 1 (DS1
[ES]), respectively. The index registers are adjusted automatically
during string transfers. Both IX [SI] and IY [DI] are accessible to
the programmer.
Program Counter
PC
The program counter is a 16-bit binary counter that contains the
offset address of the next instruction to be executed by the EXU.
The PC is automatically incremented each time the EXU reads an
instruction from the queue. If the instruction causes a branch in
program execution, the PC is programmed with the branch
address. At this point the contents of the PC are the same as the
PFP [IP]. The difference between the PFP [IP] and the PC is that
the PFP [IP] contains the offset of the next instruction to be
fetched by the BCU and the PC contains the address of the next
instruction to be executed by the EXU. The PC is not accessible
to the programmer.
5-12
Processor Description (V40)
Loop Counter
LC
LC is a binary counter used to regulate iterative operations such
as string transfers controlled by the repeat prefix and multiple-bit
shifts and rotations. The CPU uses hardware for a loop counter,
as opposed to microcode used by the traditional microprocessor.
Temporary Registers A, B, and C
TA, TB, and TC
These 16-bit registers are used by the ALU during arithmetic and
logical instructions such as multiplication, division, and shift and
rotate. TA and TB combine for 32-bit temporary storage during
multiplication and division. Access to the temporary registers is
not available to the programmer.
Arithmetic and Logic Unit
ALU
The ALU performs arithmetic and logic operations as well as bit
manipulation. Arithmetic and logic operations include add,
subtract, multiply, divide, increment, decrement, compare,
complement, AND, OR, and exclusive OR. Bit manipulation
includes shifting, rotating, comparing, setting, clearing, and
inverting of individual bits.
Effective Address Generator
EAG
The 16-bit offset address calculated by the EXU for memory
operations is called the effective address. The effective address
can include a displacement, base, index, or combination of the
three, depending on the addressing mode specified in the
instruction being executed. Traditional microprocessors calculate
this effective address using microcode. The EAG does this
calculation in hardware. As an example, the 8088 requires up to
5-13
Processor Description (V40)
12 clocks to calculate the effective address using microcode.
However, the V40 does all effective address calculations in two
clocks with the hardware EAG.
The effective address, once calculated by the EAG, is transferred
to the DP register, where it can be used by the BCU to transfer
data between the CPU and memory.
Program Status Word
PSW [FL]
There are six status flags and four control flags in the 16-bit PSW
[FL], as seen in Figure 5-3. Notice that not all 16 bits are defined.
Those not defined are reserved; that is, they may be used in later
versions of the processor. Because of this, a program should never
rely on a value in any of these reserved bits.
STATUS FLAGS:
Carry
Parity
Auxiliary Carry
Zero
Sign
Overflow
15
STATUS MD
WORD:
14
13
12
11 10
9
8
7
6
V DIR IE BRK S
Z
[OF] [DF] [IF] [TF] [SF] [ZF]
5
4
AC
[AF]
3
2
P
[PF]
1
0
CY
[CF]
CONTROL FLAGS:
Break
Interrupt Enable
Direction
Mode
Figure 5–3. Processor Status Word.
The status flags provide information about the result of arithmetic
and logic operations. The status flags are set (logical 1) and reset
(logical 0) by the EXU based on the result of an arithmetic or
logic operation. These flags can be tested by conditional jump
instructions to change the order of program execution.
5-14
Processor Description (V40)
The control flags are used by the programmer to direct CPU
operation. The control flags are set (logical 1) and reset
(logical 0) with dedicated instructions. The IE [IF] and BRK [TF]
flags are automatically reset when the program enters an interrupt
service routine.
The PSW [FL] is automatically preserved on the stack at the start
of an interrupt service routine for both hardware and software
initiated interrupts, and at the start of a procedure initiated with
the CALL instruction. A return from interrupt instruction, a return
from procedure instruction, or a return from emulation instruction
will restore the contents of the PSW [FL] from the stack.
Different instructions affect the status flags differently. A detailed
description of each status flag is given on the following pages.
Reference to bit position is based on the least significant bit being
bit 0. The state of a flag is referred to as set when a a logical 1 is
present, and as reset when a logical 0 is present.
Status Flags
CY [CF] (Carry Flag) - The carry flag is set if an addition
results in a carry out of bit 7 for byte operations or bit 15 for word
operations. The CY [CF] flag is also set if a subtraction results in
a borrow into bit 7 for byte operations or bit 15 for word
operations.
For unsigned byte multiplication, CY [CF] is reset if the most
significant byte of the result (register AH) is 0. The same is true
of the most significant word (register DW [DX]) for unsigned
word multiplication.
For signed multiplication, CY [CF] is reset if the sign bit of the
least significant byte (register AL) is extended to the most
significant byte (register AH). The same is true for signed word
multiplication with the least significant word in register AX and
the most significant in register DX.
P [PF] (Parity Flag) - The P [PF] flag is set if the least
significant byte of an arithmetic or logical result has an even
5-15
Processor Description (V40)
number of bits set. This flag is useful for checking the parity of
ASCII characters.
AC [AF] (Auxiliary Flag) - AC [AF] is set if an addition results
in a carry from the four least significant bits of the result. This is
true for both byte and word addition. This flag is used by the
CPU for BCD arithmetic operations.
Z [ZF] (Zero Flag) - Z [ZF] is set if the result of an arithmetic or
logical operation is zero. A common use of this flag is to
determine if two numbers are equal. The program subtracts the
two values and if Z [ZF] is set, the values are equal.
S [SF] (Sign Flag) - Arithmetic and logic operations set S [SF]
equal to the high order bit of the result. This is bit 7 for byte
operations and bit 15 for word operations. For signed binary
operations, S [SF] is reset for positive results and set for negative
results. Programs using unsigned operations usually ignore S [SF]
because the high order bit does not reflect the sign of the result.
V [OF] (Overflow Flag) - The V [OF] flag is set if the result of
an operation is too large a positive number or too small a negative
number to fit into the destination. The application program can
use the overflow flag to determine if the result of two’s
complement arithmetic operation is out of range.
Control Flags
MD (Mode Flag) - The CPU operates in either native or
emulation mode. In native mode, the CPU executes the standard
8086/186 instructions in addition to instructions unique to the
V40. In emulation mode, the CPU executes an 8080 based
instruction set. The MD flag is used to distinguish between the
two modes. MD is programmed using specific instructions to put
the CPU in the native mode (MD is set) or emulation mode (MD
is reset). Refer to page 5-33 for more information.
DIR [DF] (Direction Flag) - The CPU supports string operations
to manipulate linear arrays of data organized as words, bytes,
nibbles, or bits. Index registers are used to point to elements of
5-16
Processor Description (V40)
the array during a string operation. After a string operation is
completed, the index registers are incremented or decremented,
depending on the state of the DIR [DF] flag. If the DIR [DF] flag
is set, the index is incremented to point to the next array element.
If the DIR [DF] flag is reset, the index is decremented.
IE [IF] (Interrupt Enable Flag) - The IE [IF] flag determines
how the CPU responds to maskable external interrupts. If IE [IF]
is set, the CPU recognizes maskable external interrupts. The CPU
ignores all maskable external interrupts if IE is reset. IE [IF] has
no effect on external non-maskable interrupts or on internally
generated interrupts. IE [IF] is set or reset with dedicated
instructions, but will also be reset automatically with a return
from interrupt instruction.
BRK [TF] (Break Flag) - Setting the break (or trap) flag puts the
CPU into a single-step operation useful for testing program
execution. With BRK [TF] set, the CPU automatically generates
an internal interrupt after each instruction. The programmer need
only develop an interrupt service routine to examine contents of
registers, dump memory, or do whatever is necessary for testing.
The BRK [TF] flag is set or reset by transferring the PSW [FL] to
the program stack and using memory manipulation instructions to
modify it. Once BRK [TF] is modified, it must be transferred
back to the PSW [FL] to generate a type 1 interrupt after the
execution of each instruction. As part of the interrupt
acknowledge, the PSW [FL] is saved on the stack and the BRK
[TF] flag is reset. This is done so that the processor will not
single-step through the interrupt service routine. Once the service
routine is completed, the PSW [FL] is restored from the stack
automatically, setting the BRK [TF] flag to trap the next
instruction.
5-17
Processor Description (V40)
Enhanced Architecture
The V40 CPU includes several enhancements that provide an increase
in performance over the 8088 microprocessor found on many STD
bus designs. The most noticeable performance improvements come
from additional hardware for the Effective Address Generator, Loop
Counters and Shifters, and the use of dual internal data buses.
Using a hardware-effective address generator rather than microcode
reduces the time needed to fetch memory operands by as much as 10
clocks per fetch. Using hardware counters and shifters instead of the
conventional microcode increases the speed of multiply and divide
instructions by as much as four times. Dual internal data buses reduce
traffic for instructions with two operands for effective address
calculation. These enhancements add up to a speed increase of as
much as 30 percent over that of the 8088 microprocessor.
Standby Mode
The CPU’s standby mode reduces power consumption by more than
one tenth during idle periods. Standby mode is automatically entered
when the HALT instruction is executed from the native or 8080
emulation mode. This does not affect any of the internal peripherals,
such as the counter/timers, interrupt controller, refresh controller, or
DMA controller. The CPU automatically exits the standby mode after
a reset or an interrupt.
5-18
Processor Description (V40)
BIU - Bus Interface Unit
The BIU controls the external address, data, and control buses. The
BIU also synchronizes the RESET and READY inputs with the clock,
as shown in Figure 5-4. The synchronized RESET signal is used
internally. It is provided externally as a signal called RESOUT. The
synchronized READY signal is combined with the output of the Wait
Control Unit to control the number of wait states inserted during bus
operations.
CLOCK
CK
D
RESET
RESOUT
Q
To Internal Circuit
CK
CK
READY
D
Q
D
Q
To Internal Circuit
Figure 5–4. RESET and READY Synchronization.
BAU - Bus Arbitration Unit
The V40 includes two internal bus masters and two signals supporting
one external bus master. The two internal bus masters are the Central
Processing Unit and DMA Control Unit. An external master, such as
the 8087 numeric data processor, is supported with the HLDRQ and
HLDAK signals. Each of the three bus masters mentioned above
needs access to the address, data, and control buses to perform its
function. The BAU controls which of these bus masters has access to
5-19
Processor Description (V40)
the buses at any given time. The bus masters are prioritized in the
following order:
(1st) DCU - DMA Control Unit
(2nd) HLDRQ - External Bus Master
(3rd) CPU - Central Processing Unit
If the bus is being used by one bus master and another with higher
priority makes a request, the BAU inactivates the current bus master’s
acknowledge. The BAU grants access to the higher priority bus
master after the current bus master removes the request.
The BUSLOCK prefix prevents all bus masters, other than the CPU,
from gaining access to the bus. Care must be taken to prevent loss of
data in dynamic RAM when using the BUSLOCK prefix with
instructions that have a long execution time.
CGU - Clock Generator Unit
The CGU halves the frequency of the external oscillator to provide a
clock reference with a 50% duty cycle to the CPU. This same signal
is available on an external pin called CLKOUT to which all of the
V40 timing parameters are referenced.
VCR - V40 Configuration Registers
Twelve programmable registers are used to configure the V40 to meet
the needs of varying applications. The V40 configuration registers are
located in the top 16 bytes of the 64 Kbytes of I/O address space. The
configuration registers define the functions of the programmable pins;
the enabling and disabling of the SCU, TCU, ICU, and DCU; the
location of the SCU, TCU, ICU, and DCU programmable registers in
I/O address space; the wait-state configuration; DRAM refresh; and
the counter/timer clock source.
5-20
Processor Description (V40)
WCU - Wait Control Unit
The WCU provides added flexibility for interfacing to memory and
I/O that have varying speed requirements. The V40 includes three
internal bus masters that access memory and I/O devices. The number
of wait states inserted can be programmed separately for the CPU,
RCU, and DCU. The memory space can be divided into three
separate areas and the number of wait states defined differently for
each. The wait states are programmed through the WCY2, WCY1,
and WMB V40 configuration registers.
SCU - Serial Control Unit
The serial control unit is a single asynchronous serial channel used for
serial communication between the V40 and a serial device external to
the V40. Programming the SCU is similar to programming the 8251A
Serial Control Unit for asynchronous modes of operation.
TCU - Counter/Timer Control Unit
The Counter/Timer Control Unit includes three 16-bit programmable
counter/timers. These counter/timers can be used for SCU baud rate
generation, timing loops, timed and periodic interrupts, and external
asynchronous event counters. Programming the TCU is similar to
programming the 8254 Programmable Interval Timer, with a few
restrictions placed on operating modes because of the way the TCU is
connected internally to the V40.
5-21
Processor Description (V40)
ICU - Interrupt Control Unit
Interrupts provide an efficient interface between the V40 CPU and
supporting peripheral devices. The ICU supports eight interrupts
directly and can be cascaded with other interrupt controllers, such as
the 8259A Programmable Interrupt Controller, to support additional
interrupting sources. Programming the ICU is similar to programming
the 8259A.
DCU - DMA Control Unit
The DCU controls high speed data transfer between I/O and memory
devices. The DCU is similar to the 8257 Programmable DMA
Controller except that the DCU supports the full 1 Mbyte of V40
addressing space.
5-22
Processor Description (V40)
RESET
Resetting the V40 initializes registers internal to the CPU, VCR,
SCU, TCU, ICU, and DCU. The reset states for the CPU registers are
given in Table 5-3. Reset states for registers internal to the VCR,
TCU, ICU, DCU, and SCU are given in their respective chapters.
The reset states of the program segment and instruction pointer
combine to produce a physical address of FFFF0h. This is the address
from which the V40 fetches the first instruction after reset.
Table 5-3
CPU Reset State.
Register
PFP [IP]
PC
PS [CS]
SS [SS]
DS0 [DS]
DS1 [ES]
PSW [FL]
AW [AX], BW [BX]
CW [CX], DW [DX]
IX [SI], IY [DI]
BP [BP], SP [SP]
Instruction Queue
Reset Value
0000h
0000h
FFFFh
0000h
0000h
0000h
F002h
Undefined
Undefined
Undefined
Undefined
Cleared
5-23
Processor Description (V40)
MEMORY AND I/O ADDRESSING
This section discusses how the V40 communicates with memory and
I/O devices. The V40 has a 20-bit address bus and an 8-bit data bus.
With 20 bits of address, the V40 can directly access up to 1 Mbyte of
memory. The address range is from 0 to FFFFFh, as shown in
Figure 5-5. Address locations 0 to 7Fh are reserved for dedicated
interrupts and future enhancements. The address range from 80 to
3FFh completes the interrupt vector table and may be used as needed
by the application. The 12 bytes (six words) from FFFF0 to FFFFBh
are the area vectored to by the V40 after a reset. The most common
practice is to program this area with an intersegment jump to the start
of the application program. The upper four bytes are reserved and
must not be programmed.
FFFFFh
RESERVED
RESET VECTOR
FFFFCh
FFFFBh
FFFF0h
FFFEFh
GENERAL PURPOSE
INTERRUPTS
00400h
003FFh
00000h
Figure 5–5. Memory Map.
5-24
Processor Description (V40)
To the programmer, the V40 address space is organized as a
contiguous sequence of up to 1 Mbyte. Data can be addressed in units
of bytes, words, and double words. Word and double word values are
stored in memory with the most significant byte at the higher address
and the least significant at the lower. Figure 5-6 illustrates these data
formats.
N
7
0
Byte Data
N+1
N
15
8
7
0
Word Data
N+3
31
24
N+2
23
16
N+1
15
8
7
0
N
Double Word Data
Figure 5–6. Data Formats.
5-25
Processor Description (V40)
The lower 16 of the 20 address lines are also used to address I/O
devices. With 16 bits of address, the V40 can directly access up to
64 Kbytes of I/O. The address range is from 0 to FFFFh, as shown in
Figure 5-7. Address locations FF00 through FFEFh are reserved for
future use. The address range from FFF0 through FFFFh is currently
used for the V40 configuration registers. These registers define programmable options in the V40, such as wait-state insertion, location
of internal peripheral device registers, enabling DRAM refresh, and
selecting the period of refresh.
FFFFh
DEDICATED
FFF0h
FFEFh
RESERVED
FF00h
FEFFh
GENERAL PURPOSE
0000h
Figure 5–7. I/O Map.
5-26
Processor Description (V40)
INTERRUPTS
The V40 includes a versatile interrupt structure that supports both
hardware and software initiated interrupts. Hardware interrupts are
external inputs to the V40 and can be classified as maskable or nonmaskable. Maskable interrupts are routed to the CPU through the
ICU. The ICU provides the maskable interrupt inputs with the ability
to be level- or edge-triggered, have fixed or rotating priorities, and be
individually masked. Non-maskable interrupts are routed directly to
the CPU and are not maskable through programming.
Software interrupts are internally generated during program
execution. They include instructions that can be executed to generate
interrupts, and error handling instructions for such things as a divide
overflow. Table 5-4 on page 5-28 lists the sources of hardware and
software interrupts. The remainder of this section explains these
interrupts and how the V40 handles them.
5-27
Processor Description (V40)
Table 5-4
Interrupt Sources.
Software
Interrupt Source
Clocks
Priority
DIVU divide error
45
1
DIV divide error
45-55
1
CHKIND breakout error
53-56
1
BRKV
40
1
BRK3
38
1
BRK imm8
38
1
BRKEM imm8
38
1
CALLN imm8
38
1
BRK single step
38
4
38
2
49
3
Hardware NMI
ICU inputs
5-28
Processor Description (V40)
The purpose of an interrupt is to redirect the CPU from its current
activity to an interrupt service routine designed to handle the needs of
the interrupting source. Every interrupting source is associated with a
number that points the CPU to a location in memory that contains the
address of the interrupt service routine. This number is called an
interrupt vector. The area in memory where the addresses of the
interrupt service routines are stored is called the interrupt vector table.
During an interrupt cycle, the CPU multiplies the vector by four to
obtain the location of the service routine address in the vector table.
The CPU then transfers control to the service routine at the address
read from the vector table. (See Figure 5-8.) It is the programmer’s
responsibility to load the address of the service routine into the vector
table. The address includes a segment and offset value in the format
shown.
0
7
•
•
•
NMI (N=2)
ICU
CPU
Programmed To
Provide Unique
Vector (N) For
Each Input
Multiplies Vector
(N) By Four
N
x4
4N
MEMORY
4N
4N+1
Offset
PFP (IP)
4N+2
4N+3
Segment
PS (CS)
Interrupt
Service
Routine
Figure 5–8. Interrupt Processing.
5-29
Processor Description (V40)
The vector of an interrupt source must be known before the location
of the service routine address can be determined. The interrupt vector
table, shown in Table 5-5, lists the vectors for the sources of
interrupts. As an example, assume you need to write a service routine
to handle a non-maskable interrupt (NMI) request. The vector for
NMI is two, as seen in the Table 5-5. The address of the NMI service
routine is determined by the application, but that address must be
programmed in the vector table at 8h.
Table 5-5
Interrupt Vector Table.
Software
Interrupt Source
Vector Number
DIVU divide error
0
DIV divide error
0
CHKIND breakout error
5
BRKV
4
BRK3
3
BRK imm8
32-255
BRKEM imm8
32-255
CALLN imm8
32-255
BRK single step
Hardware NMI
ICU inputs
5-30
1
2
32-255
Processor Description (V40)
Before describing each source of interrupt shown in the vector table, it
is useful to summarize the operation of the CPU in response to an
interrupt. Interrupts come to the CPU from three sources: the NMI
signal external to the V40, the output of the ICU, and from inside to
the CPU itself. A vector is supplied in all cases to distinguish between
the interrupting sources. The CPU determines the address of the
service routine by multiplying the vector times four. Before
transferring execution to the service routine, the CPU saves the
machine status by pushing the current contents of the PSW [FL] and
the return address onto the stack. The CPU then clears the BRK [TF]
and IE [IF] flags to prevent subsequent single-step and maskable
interrupts, and transfers program execution to the service routine. The
service routine is terminated with a "return from interrupt" instruction.
This instruction causes the CPU to restore the PSW [FL] from the
stack and return execution to the interrupted program. Restoring the
PSW [FL] automatically enables single-step and maskable interrupts.
Divide Error
The divide error interrupt is generated by the CPU following
execution of a DIV [DIV] or DIVU [IDIV] instruction if the
calculated quotient is larger than the specified destination. The
interrupt is not maskable and the vector is fixed at zero.
Single-Step
The single-step interrupt is a powerful software debugging tool. The
purpose of the single-step interrupt is for software single stepping
through a sequence of code. This interrupt is controlled by the BRK
[TF] flag in the PSW [FL]. There is no instruction to set the BRK
[TF] flag. To set the BRK [TF] flag, the PSW [FL] register must be
pushed on the stack, the flag set, and the PSW [FL] popped back off
the stack. With the BRK [TF] flag set, a single-step interrupt is
generated after each instruction. The CPU responds to the interrupt by
pushing the PSW [FL], PS [CS], and PFP [IP] on the stack. The BRK
[TF] and IE [IF] are reset to a logical 0 to prevent another single-step
or maskable interrupt. Upon completion of the single-step routine, the
5-31
Processor Description (V40)
CPU restores the PSW [FL], PS [CS], and PSP [IP]. The single-step
interrupt is not masked by the IE [IF] bit in the PSW [FL].
Non-Maskable
The V40 has a non-maskable interrupt input called NMI. NMI is
rising edge triggered but must remain active for two CPU clocks to
guarantee recognition. This interrupt is not maskable and the vector is
fixed at 2.
Fixed Vector Instruction
The fixed vector instruction (BRK3 [INT3]) is a special form of the
more general variable vector instruction. The difference is that the
fixed vector is a single byte while the variable vector requires 2 bytes.
The primary use of this instruction is for breakpoint execution during
program development. Because it is a single byte, the instruction can
be mapped over the smallest possible instruction. This interrupt is not
maskable and has a fixed vector of 3.
Overflow
The overflow interrupt is generated if the V [OF] flag is set to a
logical 1 and the BRKV [INTO] instruction is executed. This
interrupt is useful for trapping overflow errors for mathematical
operations. The overflow interrupt is not maskable and the vector is
fixed at 4.
5-32
Processor Description (V40)
Check Index
The purpose of the check index instruction is to test the index of an
array against an upper and lower limit. The CHKIND [BOUND]
instruction generates a check index interrupt if the index value is less
than the lower limit or greater than the upper limit. The vector for the
check index instruction is fixed at 5 and is not maskable.
Variable Vector Instruction
Interrupts can be generated using a variable vector interrupt
instruction with the format BRK [INT] xx, where xx is the vector
number. Accessing subroutines in this manner means only the
subroutine vector is fixed. The location and length of the subroutine
can vary without affecting the main program. These interrupts cannot
be masked.
Emulation Mode
Two interrupt instructions deal with 8080 emulation mode. The
BRKEM instruction is used to transfer V40 operating modes from
native to emulation for execution of 8080 based programs. The
CALLN instruction is used in emulation mode to call an 8088
procedure. Both instructions have the format and operation of the
variable vector instruction. The following pages discuss 8080
emulation in detail.
5-33
Processor Description (V40)
8080 EMULATION
Designs based on 8080 and 8085 microprocessors have two major
limitations: inadequate performance and lack of development tools.
Upgrading an 8-bit design to a higher performance microprocessor
requires time to convert the software. The V40 solves these problems
by supporting two modes of operation: emulation mode and native
mode. When the CPU is in emulation mode, it executes the 8080
instruction set. Emulation mode is used for the existing software base.
In native mode, the CPU executes the 8088 instruction set. All future
software development is done in native mode to take advantage of the
8088 instruction set and the large number of development tools
designed around it.
The CPU powers up in native mode, the normal mode of operation.
Two instructions are provided to switch the CPU from native mode to
emulation mode and back. Break for Emulation (BRKEM) is the
instruction used to switch from native to emulation mode; Return
from Emulation (RETEM) is used to switch back. The effect of these
instructions and emulation mode operation is discussed below.
The BRKEM instruction is similar to the BRK [INT] software
interrupt. BRKEM includes an 8-bit vector that, when multiplied by
four, points to the location in the interrupt vector table that contains
the address of the 8080-based routine. During execution of this
instruction, the CPU saves the machine status by pushing the current
contents of the PSW [FL] and the return address onto the stack. The
CPU then clears the mode (MD) flag to a logical 0 and loads the
address of the emulation mode routine into the PS [CS] and PFP [IP].
The RETEM instruction is one of the four methods of terminating
emulation mode. The execution of RETEM is identical in operation to
the RETI [IRET] instruction. Upon executing this instruction, the
CPU restores the contents of the PSW [FL], PS [CS], and PFP [IP]
from the stack, returning program execution to the instruction
following BRKEM. The other three methods of exiting emulation
mode are a system reset, a hardware interrupt, or the CALLN
instruction.
5-34
Processor Description (V40)
A hardware interrupt suspends the 8080 emulation mode. The CPU
pushes the PSW [FL] and return address onto the native mode stack,
sets the MD flag to a logical 1, and transfers program execution to the
native mode interrupt service routine. When the CPU executes the
RETI [IRET] instruction, the PSW [FL] is restored with the MD flag
set to a logical 0, and program execution continues in the emulation
mode. The CALLN instruction permits the execution of native mode
subroutines from emulation mode. The CPU responds to CALLN in
the same manner as a hardware interrupt.
The emulation mode cannot be nested. For example, assume that the
CPU is operating in native mode and executes the BRKEM
instruction. The CPU switches to native mode and begins executing
emulation code. Next, assume that a hardware interrupt (such as the
16450 serial controller) suspends emulation mode and the CPU begins
executing the interrupt service routine in native mode. That interrupt
service routine cannot include a BRKEM instruction.
Table 5-6 on page 5-36 shows the relationship between the native and
emulation mode registers and flags. The native mode registers not
shown are inaccessible to 8080 programs; they are AH [AH], PS
[CS], SS [SS], DS0 [DS], DS1 [ES], IX [SI], IY [DS], and the upper
eight bits of the PSW [FL].
Memory addressing and stack referencing must also be considered.
The 8080 addresses a maximum of 64 Kbytes. This block of memory
can be located anywhere in the 1 Mbyte address space by programming the PS [CS] word in the interrupt vector table before the
BRKEM instruction is executed. All data and stack operations are
referenced from the DS0 [DS] register. This register must be
initialized before the BRKEM instruction is executed. The values in
the PS [CS] and DS0 [DS] registers must be equal for complete
compatibility with the 8080 structure.
5-35
Processor Description (V40)
Emulation mode uses the BP [BP] register for the stack pointer, rather
than the native mode SP [SP] register, to reduce the possibility of
programming errors in one mode corrupting the stack of the other.
This feature is helpful during program development.
Table 5-6
Emulation Mode Registers and Flags.
Registers
Flags
5-36
8080
8088
A
B
C
D
E
H
L
SP
PC
AL
CH
CL
DH
DL
BH
BL
BP
PC
C
Z
S
P
AC
CY
Z
S
P
AC
Chapter 6
PROCESSOR CONFIGURATION (V40)
Contents
Page
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
VCR - V40 CONFIGURATION REGISTERS . . . . . . . . . . . . . . . . . . . . . . . 6-2
OPCN - On Chip Peripheral Connection Register . . . . . . . . . . . . . . . . 6-3
OPSEL - On Chip Peripheral Selection Register . . . . . . . . . . . . . . . . . 6-4
OPHA, DULA, IULA, TULA, and SULA . . . . . . . . . . . . . . . . . . . . . . . 6-5
WCY2 - Wait Cycle 2 Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
WCY1 - Wait Cycle 1 Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
WMB - Wait Memory Boundary Register . . . . . . . . . . . . . . . . . . . . . . . 6-9
RFC - Refresh Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10
TCKS - Counter/Timer Clock Selection Register . . . . . . . . . . . . . . . . 6-10
RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12
OVERVIEW
The V40 is a high integration microprocessor containing a CPU and
several peripherals most commonly found in STD bus systems. The
V40 also includes a software-programmable register set that
configures these peripherals to specific applications. This chapter
explains the architecture and use of these configuration registers.
6-1
Processor Configuration (V40)
VCR - V40 CONFIGURATION REGISTERS
The 12 V40 configuration registers are mapped from I/O address
FFF0h through FFFFh. The registers are listed in Table 6-1 and are
discussed in detail on the following pages. All of the registers can be
written to with the output instruction and read from with the input
instruction. The value input may be different from the value output,
but only in the bits not defined.
Table 6-1
V40 Configuration Registers.
I/O
Address
Register
Function
FFFFh
FFFEh
FFFDh
FFFCh
FFFBh
FFFAh
FFF9h
FFF8h
FFF7h
FFF6h
FFF5h
FFF4h
FFF3h
FFF2h
FFF1h
FFF0h
Reserved
OPCN
OPSEL
OPHA
DULA
IULA
TULA
SULA
Reserved
WCY2
WCY1
WMB
Reserved
RFC
Reserved
TCKS
-V40 multiplexed pin assignment
V40 peripheral enable
V40 peripheral I/O address (MSB)
DCU I/O address (LSB)
ICU I/O address (LSB)
TCU I/O address (LSB)
SCU I/O address (LSB)
-DCU wait states
CPU memory and I/O wait states
Memory wait state boundaries
-Refresh enable, frequency select
-Timer/counter clock selection
6-2
Processor Configuration (V40)
OPCN - On Chip Peripheral Connection Register
Figure 6-1 shows the OPCN register. Bit 0 must be programmed with
a logical 0 and bit 1 must be programmed with a logical 1.
The two bits of the IRSW field select the interrupt source to be
assigned to IRQ1 and IRQ2 of the interrupt controller. The values
programmed into bits 2 and 3 depend on the use of the interrupt
controller in the application. The pins external to the V40 used for
IRQ1 and IRQ2 are connected to Stage 1 of the watchdog timer and
Interrupt 0 of the SBX expansion module, respectively. The
STD ROM software initializes OPCN to a 06h to use the V40 serial
port.
7
6
5
4
3
2
1
0
—
—
—
—
IRSW
1
0
Register: OPCN
Address: FFFEh
Interrupt Request Switch
INT1
INT2
00 IRQ1 pin
IRQ2 pin
01 SCU
IRQ2 pin
10 IRQ1 pin
TOUT1
11 SCU
TOUT1
Figure 6–1. On Chip Peripheral Connection Register.
6-3
Processor Configuration (V40)
OPSEL - On Chip Peripheral Selection Register
The V40 integrates several of the most common peripheral devices
with a CPU in one package. The peripheral devices include a serial
port, an interrupt controller, a DMA controller, and three
counter/timers. The OPSEL register enables or disables these
peripheral devices. The format of the OPSEL register is shown in
Figure 6-2. No restrictions are placed on the use of the OPSEL
register. The STD ROM software initializes OPSEL to a 0Eh to
enable the V40 serial port and the counter/timers for baud rate
generation.
7
6
5
4
3
2
1
0
—
—
—
—
SS
TS
IS
DS
Register: OPSEL
Address: FFFDh
DMAU Select
0 Disabled
1 Enabled
ICU Select
0 Disabled
1 Enabled
TCU Select
0 Disabled
1 Enabled
SCU Select
0 Disabled
1 Enabled
Figure 6–2. On Chip Peripheral Selection Register.
6-4
Processor Configuration (V40)
OPHA, DULA, IULA, TULA, and SULA
Five registers determine the I/O base address of the programmable
registers used to communicate with the DMA controller, interrupt
controller, timer/counters, and serial controller.
OPHA DULA IULA TULA SULA -
On Chip Peripheral High Address register (FFFCh)
DMA Unit Low Address register (FFFBh)
Interrupt Unit Low Address register (FFFAh)
Counter/timer Unit Low Address register (FFF9h)
Serial Unit Low Address register (FFF8h)
The I/O base address is a 16-bit value made up of two 8-bit values.
The upper 8 bits of the address for the DMA controller, interrupt
controller, counter/timers, and serial controller are defined by the
OPHA register. The lower 8 bits for the DMA channel are
programmed in the DULA register. The same holds true for the
interrupt controller and IULA register, for the counter/timers and
TULA register, and for the serial controller and SULA register.
In operation, OPHA permits the four internal peripheral devices to be
mapped to any 256 byte block in the 64K I/O address space. The
individual registers DULA, IULA, TULA, and SULA are
programmed to define the base address of each of these devices
anywhere within this block. For example, if the interrupt controller is
to be mapped starting at I/O address FF20h, OPHA must be
programmed with a FFh and IULA with a 20h.
6-5
Processor Configuration (V40)
The only restriction placed on programming these registers is to be
sure the peripherals internal to the V40 are not mapped in the same
address range as other I/O devices local to the ZT 8832. The STD
ROM software programs these registers with the values shown in
Table 6-2.
Table 6-2
STD ROM Programmable Address Selection.
6-6
Register
Value
OPHA
DULA
IULA
TULA
SULA
00
D0
20
40
B0
I/O Port
Address
---00D0h
0020h
0040h
00B0h
Processor Configuration (V40)
WCY2 - Wait Cycle 2 Register
The V40 includes a programmable wait-state generator that interfaces
to memory and I/O devices that are not fast enough to operate without
wait states. The wait-state generator is programmed through the
WCY2, WCY1, and WMB configuration registers. The format of the
WCY2 register is shown in Figure 6-3. Bit 2 must be programmed
with a logical 0 and bit 3 must be programmed with a logical 1 to
select two wait states into DMA cycles. Two wait states are required
to meet the SBX expansion module timing requirements. The STD
ROM software initializes the WCY2 register with a 08h.
7
6
5
4
3
2
1
0
—
—
—
—
1
0
—
—
Register:WCY2
Address:FFF6h
Figure 6–3. Wait-Cycle 2 Register.
WCY1 - Wait Cycle 1 Register
The WCY1 register is divided into four fields as shown in Figure 6-4
on page 6-8. The first three fields define the number of wait states
inserted into three different regions of memory defined by the WMB
register. The Lower Memory Wait (LMW) field defines the number
of wait states inserted for memory accesses into the low memory
region. The Middle Memory Wait (MMW) field defines the number
of wait states inserted for memory accesses into the middle memory
region. The Upper Memory Wait (UMW) field defines the number of
wait states inserted for memory accesses into the upper memory
region.
6-7
Processor Configuration (V40)
The ZT 8832 does not require any memory wait states if memory
devices with access times less than 250 ns are used. To select zero
memory wait states, program bits 0 through 5 with logical 0s.
Programming bit 6 with a logical 0 and bit 7 with a logical 1 selects
the two I/O wait states required by peripherals on the ZT 8832. The
STD ROM software programs the WCY1 register with an 80h.
7
6
5
4
1
0
UMW
3
2
MMW
1
0
LMW
Register:WCY1
Address:FFF5h
Lower Memory Region
00 0 wait states
01 1 wait state
10 2 wait states
11 3 wait states
Middle Memory Region (STD Bus)
00 0 wait states
01 1 wait state
10 2 wait states
11 3 wait states
Upper Memory Region
00 0 wait states
01 1 wait state
10 2 wait states
11 3 wait states
Figure 6–4. Wait-Cycle 1 Register.
6-8
Processor Configuration (V40)
WMB - Wait Memory Boundary Register
The ZT 8832 does not require any wait memory wait states if memory
devices with access times less than 250 ns are used. If slower memory
devices are used, the WMB register divides the ZT 8832 memory into
three regions and the WCY1 register defines the number of wait states
inserted into each. As shown in Figure 6-5, the WMB register is
divided into Upper Memory Boundary (UMB) and Lower Memory
Boundary (LMB) fields.
7
—
6
5
LMB
4
3
—
2
1
UMB
0
Register:WMB
Address:FFF4h
Upper Memory Block Size
000 32 Kbytes
001 64 Kbytes
010 96 Kbytes
011 128 Kbytes
100 192 Kbytes
101 256 Kbytes
110 384 Kbytes
111 512 Kbytes
Lower Memory Block Size
000 32 Kbytes
001 64 Kbytes
010 96 Kbytes
011 128 Kbytes
100 192 Kbytes
101 256 Kbytes
110 384 Kbytes
111 512 Kbytes
FFFFFh
00000h
Higher Memory Block (UMB)
Middle Memory Block (MMB)†
Lower Memory Block (LMB)
† MMB is defined as the address range between
LMB and UMB.
Figure 6–5. Wait-Cycle Memory Boundary Register.
6-9
Processor Configuration (V40)
The Middle Memory Block is defined between the top of the LMB
and the bottom of the UMB. Offboard memory (STD bus) requires
one wait state in all cases and is defined by the MMB.
The LMB field defines the lower memory address range starting from
zero. This field can be programmed to include the memory devices
inserted into the RAM LOW and RAM HIGH sockets. The UMB
field defines the upper memory address range ending at FFFFFh. This
field can be programmed to include the memory device inserted into
the ROM socket. The STD ROM software initializes all bits of the
WMB register to logical 0s.
RFC - Refresh Control Register
The refresh controller is not used by the ZT 8832. To prevent the
refresh controller from affecting system performance, program bit 7
with a logical 0 (see Figure 6-6).
7
6
5
4
3
2
1
0
0
—
—
—
—
—
—
—
Register:RFC
Address:FFF2h
Figure 6–6. Refresh Control Register.
TCKS - Counter/Timer Clock Selection Register
The V40 includes three programmable counter/timers. The TCKS
register, shown in Figure 6-7, selects the clock source for each
counter/timer, and also selects a frequency divisor that is used by all
three counter/timers.
6-10
Processor Configuration (V40)
The CS0, CS1, and CS2 (Clock Select 0, 1, and 2) bits select the
counter/timer clock source to be either the reference clock internal to
the V40 or the TCLK pin available on an external V40 pin. The V40
clock operates at 8 MHz with a 50% duty cycle. The TCLK signal is
available through connector J3. The Prescale (PS) field selects a
prescale value that divides the clock frequency of all counter/timers
using the V40 internal clock, then applies that value to the
counter/timers. The STD ROM software programs all bits of TCKS
with logical 0s to configure counter/timer 1 for baud rate generation.
7
6
5
—
—
—
4
3
2
CS2 CS1 CS0
1
0
PS
Register:TCKS
Address:FFF0h
Prescale Select for Internal Clock
00 Clock prescaled by 2
01 Clock prescaled by 4
10 Clock prescaled by 8
11 Clock prescaled by 16
Counter/Timer 0 Clock Source
0 Internal clock
1 TCLK pin
Counter/Timer 1 Clock Source
0 Internal clock
1 TCLK pin
Counter/Timer 2 Clock Source
0 Internal clock
1 TCLK pin
Figure 6–7. Timer/Counter Clock Selection Register.
6-11
Processor Configuration (V40)
RESET
The V40 configuration registers are automatically initialized to a
default state when power is applied to the V40 and also during reset
from an external source. Table 6-3 shows the default state of the
configuration registers.
Table 6-3
V40 Configuration Register Defaults.
Registers
7
Default Bit Values[1]
6
5
4
3
2
OPCN
OPSEL
OPHA
DULA
IULA
TULA
SULA
WCY2
WCY1
WMB
RFC [2]
TCKS
1
-
1
-
1
-
1
0
0
0
0
1
1
1
0
0
0
1
1
0
0
1
0
0
0
1
1
0
0
0
0
1
1
0
0
[1] Bit Positions marked with a dash (-) can default to 1 or 0.
[2] The refresh enable bit of the RFC register is not affected by resets other than
power on.
6-12
Chapter 7
COUNTER/TIMERS (V40)
Contents
Page
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
ZT 8832 SPECIFICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
Read/Write Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
Mode Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5
Clock Select and Divisor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5
Counter/Timers 0, 1, and 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5
PROGRAMMABLE REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7
Timer Mode Register (TMD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8
Count Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12
Status Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14
Count Latch Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14
Multiple Latch Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-15
Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-16
Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-28
7-1
Counter/Timers
OVERVIEW
This chapter describes the Counter/Timer Control Unit (TCU) and
provides register descriptions.
The TCU includes three 16-bit programmable counter/timers.
Applications for the counter/timers include baud rate generation for
the serial controller, timing loops, timed and periodic interrupts, and
asynchronous event counters.
The main features of the TCU are:
•
Three 16-bit counter/timers
•
Six programmable operating modes
•
Binary and BCD counting
•
Interrupt and polled operation
•
Functionally equivalent to 8254
7-2
Counter/Timers
ZT 8832 SPECIFICS
The clock source for each counter/timer is defined in the TCKS V40
configuration register. Choices for the clock source are either the V40
internal clock or the TCLK signal. The clock internal to the V40 has a
frequency of 8 MHz and a duty cycle of 50%. The TCLK signal is
available through connector J3. The TCLK signal must meet the
following requirements:
•
Operating frequency between DC and 8 MHz
•
Rise and fall times less than 25 ns
•
Clock low and clock high times greater than 50 ns
Counter/timers 0 and 1 have implied uses because of their dedicated
output connections to other devices internal to the V40. The output of
counter/timer 0 is connected to IRQ0 of the interrupt controller. This
dedicates counter/timer 0 to generating timed or periodic interrupts.
The output of counter/timer 1 is connected to the V40 serial port for
baud rate generation. The output of counter/timer 1 can also be
connected to IRQ2 of the interrupt controller if the V40 serial port is
not needed. This connection is made with the OPCN V40
configuration register.
Counter/timer 2 does not have an implied use. The output (TOUT2)
and control (TCTL2) signals for counter/timer 2 are available through
connector J3, to be used as required by the application.
7-3
Counter/Timers
FUNCTIONAL DESCRIPTION
The TCU is similar to the 8254 Programmable Interval Timer in that
the programmable registers are the same. Some restrictions apply to
the operating modes of individual counter/timers because they are
connected to the V40 internally and external control inputs are not
available. These restrictions are discussed below in an explanation of
individual operating modes. Figure 7-1 illustrates the major functional
blocks of the TCU. These functional blocks are discussed in the
following paragraphs.
TCLK
(Connector J3)
TCTL2
(Connector J3)
V40 CLOCK
(Internal)
Clock Select and Divisor
IORD IOWR A1 A2 EN
CLK
CLK
CLK
Counter/ Timer 2
Control Logic
ReadWrite Control
Status
Register
Status
Latch
Mode Register
Counter/
Timer 1
16-Bit Down Counter
High
Byte
Low
Byte
Count
Register
High
Byte
Counter/
Timer 0
Low
Byte
Count
Latch
TOUT2
(Connector J3) TOUT1
(ICU, SCU )
TOUT0
(ICU)
Internal Data Bus
Figure 7–1. Counter/Timer Block Diagram.
Read/Write Control
This functional block monitors I/O control and address signals to
select programmable registers and control data flow.
7-4
Counter/Timers
Mode Register
The 8-bit Mode register is programmed to control the operation of the
counter/timers.
Clock Select and Divisor
The difference between a timer and a counter is the clock source. The
clock source for a timer is periodic, while the clock source for a
counter is usually not periodic. A timer is used to reduce the
frequency of a periodic signal; a counter is used to monitor the
occurrence of asynchronous events. The Clock Select module defines
the clock source for each counter/timer based on the value
programmed into the TCKS V40 configuration register.
Clock source choices are either the V40 internal clock or the TCLK
signal available on an external V40 pin. The internal clock is useful
for counter/timers used in applications needing baud rate generation
for the V40 serial port, accurate timing loops, timed interrupts, or
periodic interrupts. The TCLK selection is useful for applications
needing to count external events.
The Divisor, which operates on the counter/timers using the V40
internal clock as the clock source, is programmed through the TCKS
V40 configuration register to divide the V40 clock by two, four, eight,
or 16 before input to the counter/timer occurs.
Counter/Timers 0, 1, and 2
The functional block diagram shown in Figure 7-1 illustrates the
internal blocks of counter/timer 2. These internal blocks are the same
as for counter/timer 0 and counter/timer 1. Each counter/timer is
based on a 16-bit synchronous Down Counter, which can be preset to
an initial number of counts and programmed for either binary or BCD
(Binary-Coded-Decimal) operation.
7-5
Counter/Timers
The Count register and Count Latch are the interface through which
the count data is transferred between the TCU and the CPU. The
Count register receives the count value programmed to the TCU. The
count value can be either 8 bits or 16 bits. Eight-bit values can be
specified as either upper or lower bytes.
A useful feature of counter/timers is that they can be read at any time.
It may be necessary to read a counter while an application is operating
to determine how much time remains in a timing loop, or how many
external events have occurred. The contents of the Down Counter,
however, can change during the read operation, producing undefined
results.
While one solution is to stop the Down Counter, this causes
inaccuracies in the overall timing loop, or may cause an external event
to be missed. The TCU solves this problem with the Count Latch and
with commands that freeze the contents of the Count Latch without
affecting the Down Counter. The Count Latch normally holds the
current value of the Down Counter. When the TCU receives a count
latch command, the Count Latch stops changing long enough for the
read operation to occur, then returns to tracking the contents of the
Down Counter.
The Status register contains information about the counter/timer’s
operation, such as the programmed operating mode. This eliminates
the need for application software to store this information. The Status
Latch allows the status to be read during times when status bits may
be changing.
The Control Logic manipulates other functional blocks of the
counter/timer, depending on which of the six programmable operating
modes is selected, the state of the clock (TCLK), and, for
counter/timer 2 only, the control input (TCTL2).
7-6
Counter/Timers
PROGRAMMABLE REGISTERS
Four separately addressable registers are used for communication with
the TCU. The TMD (Timer Mode) register specifies the operation of
the three counter/timers. The TMD is a write-only register. The other
three bidirectional registers, called the Count and Status registers, are
used to write the count to the counter/timers and read the count and
status back.
The base I/O address of the TCU registers is defined by the OPHA
and TULA registers. OPHA is programmed with the high byte and
TULA with the low byte of the 16-bit address. Refer to Chapter 6 for
a complete discussion on the V40 configuration registers, including
OPHA and TULA. The address of the TCU registers, relative to the
base address, is shown in Table 7-1.
Table 7-1
TCU Register Addressing.
Address
Register
Operation
Page Number
Base + 0
Base + 0
Base + 1
Base + 1
Base + 2
Base + 2
Base + 3
TCT0 Count
TCT0 Status
TCT1 Count
TCT1 Status
TCT2 Count
TCT2 Status
TMD
Read/Write
Read
Read/Write
Read
Read/Write
Read
Write
7-12
7-12
7-12
7-12
7-12
7-12
7-8
7-7
Counter/Timers
Timer Mode Register (TMD)
The counter/timers must be initialized with the 8-bit TMD register.
The three formats for the TMD register are shown in Figures 7-2, 7-3,
and 7-4 (pages 7-9 to 7-11). The General Mode format is programmed initially to define the operation of the counter/timers. The
Count Latch Mode and Multiple Latch Mode are programmed at any
time to read the count and status data while the counter/timers are
operating.
General Mode
The General Mode format, shown in Figure 7-2, specifies the
operating mode of the individual counter/timers. The Select
Counter bits specify the Multiple Latch command, or which
counter/timer will receive the mode. Selecting the Multiple Latch
command changes the definition of the TMD register bits to that
of the Multiple Latch Mode format. The following bit definitions
apply only if the Multiple Latch and Count Latch options are not
programmed.
The Read/Write Mode bits specify the Count Latch command, or
the format of the count transferred between the CPU and the
TCU. Selecting the Count Latch command redefines the bits of
the TMD register to that of the Count Latch Mode format.
The count transferred to or from the 16-bit counter/timers is one
or two 8-bit values, depending on the Read/Write Mode bits. If
the low byte option is chosen, the 8-bit count transferred to the
counter/timer is placed into the low byte of the Down Counter
and the high byte is automatically set to zero. The high byte
option means that the 8-bit count is transferred to the upper byte
of the Down Counter with the low byte set to zero. Selecting the
two-byte option prepares the counter/timer to receive two bytes,
placing the first into the lower byte of the Down Counter and the
second into the upper.
7-8
Counter/Timers
A new count can be written into the counter/timers at any time
without reprogramming the TMD register. Care must be taken to
be consistent with the Read/Write Mode each time the new count
is programmed. As an example, assume that counter/timer 0 is
programmed with a Read/Write Mode of two bytes. Two bytes
must be written to counter/timer 0 each time a new count is
specified. The same applies for reading counter/timer 0; that is,
two count bytes must be read at a time.
7
6
SC
5
4
RWM
3
2
CMODE
1
0
BD
Register: Timer Mode (TMD)
Address: Base + 3
Binary or BCD
0 Binary
1 BCD
Count Mode
000 Mode 0
001 Mode 1
x10 Mode 2
x11 Mode 3
100 Mode 4
101 Mode 5
Read/Write Mode
00 Count Latch command
01 Lower byte only
10 Higher byte only
11 Lower byte followed by
higher byte
Select Counter
00 TCT0
01 TCT1
10 TCT2
11 Multiple Latch command
Note: x = Don’t Care
Figure 7–2. Counter/Timer General Mode Register.
7-9
Counter/Timers
Each counter/timer must be programmed to operate in one of six
possible count modes. Selection of the count mode is based on the
needs of the application. The counting operation of each
counter/timer is programmed as either binary or Binary-CodedDecimal (BCD). The range of a counter/timer programmed for
binary operation is 0 to FFFFh, while the BCD operation range is
0 to decimal 9999.
Count Latch Mode
The Count Latch Mode, shown in Figure 7-3, requires that the
first six bits be set to a logical 0. The Select Counter bits specify
which counter/timer’s data is to be latched.
7
6
SC
5
4
3
2
1
0
0
0
0
0
0
0
Register: Timer Mode (TMD)
Address:Base + 3
Select Counter
00 Latch CNT0
01 Latch CNT1
10 Latch CNT2
11 Multiple Latch
Figure 7–3. Counter/Timer Count Mode Register.
7-10
Counter/Timers
Multiple Latch Mode
Programming the Select Counter bits of the TMD to logical 1s
defines the Multiple Latch command (see Figure 7-4). The
CNT0, CNT1, and CNT2 bits select which of the counter/timers
will be latched. The Status Latch and Count Latch bits determine
whether the status, the count, or both are to be latched. The status
must be latched to be read. The count can be read without being
latched, but will be invalid if it is changing at the time of the read.
7
6
5
1
1
CL
4
3
2
1
SL CNT2 CNT1 CNT0
0
0
Register: Timer Mode (TMD)
Address:Base + 3
Counter/Timer 0 Select
0 CNT0 not selected
1 CNT0 selected
Counter/Timer 1 Select
0 CNT1 not selected
1 CNT1 selected
Counter/Timer 2 Select
0 CNT2 not selected
1 CNT2 selected
Status Latch
0 Latched
1 Not latched
Count Latch
0 Latched
1 Not latched
Figure 7–4. Counter/Timer Multiple Mode Register.
7-11
Counter/Timers
Count Registers
The Count register is illustrated in Figure 7-5. Unlike the Mode
register, there is one Count register for each of the three
counter/timers. The Count register transfers count values to and from
the Down Counter. The 16-bit register is programmed with a high
byte, low byte, or both high and low byte, as specified with the
Read/Write Mode bits in the Mode register. If the high byte or low
byte mode is selected, only one read or write operation is needed for
data transfers. Two read or write operations are required for the twobyte mode, with the low byte transferred first, followed by the high
byte.
15
14 13
12
11
10
9
8
7
6
5
4
3
2
1
0
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
Count
Base +
Channel
Number
Figure 7–5. Counter/Timer Count Register.
Status Registers
Each counter/timer includes a Status register. The status can be read
from the Status register at any time. The format for the status is
shown in Figure 7-6.
The first six bits of the Status register provide information about the
programmed state of the selected counter/timer. This information is in
the Status register to prevent the application software from having to
save it. The Null Count bit flags when the last count written to the
Count register is transferred to the Down Counter. This is designed to
prevent the application software from reading the Down Counter
before it is updated to the last count written. The Output Level bit
contains the current state of the counter/timer output (TOUT).
7-12
Counter/Timers
The Multiple Latch command must be used to read the status. The
number of required read operations depends on the Read/Write Mode
and the Multiple Latch command. If the Read/Write Mode is high
byte or low byte and only the status is latched with the Multiple Latch
command, one read operation is all that is needed. Two reads are
required if both the status and the count are latched by the Multiple
Latch command. The first read is for the status and the second is for
the data. If the Read/Write Mode is programmed for two-byte
transfers and the Multiple Latch command is programmed to latch
only the status, one read is all that is required. If both the status and
data are latched, three reads are required. The first read is for the
status, and the next two are for the low byte and high byte of the
count, respectively.
7
6
OL
NC
5
4
RWM
3
2
CMODE
1
0
BD
Register: Status
Address:Base + Channel No.
See TMD Register
See TMD Register
See TMD Register
Null Count
0 Count data valid
1 Count data invalid
Output Level
0 Output level low
1 Output level high
Figure 7–6. Counter/Timer Status Register.
7-13
Counter/Timers
OPERATION
Reset
The TCU registers are not initialized to a default state after power on
or reset.
Count Latch Command
The count of any counter/timer can be read at any time. The Count
Latch command must be used to guarantee accurate results. Without
the Count Latch command, the count may change during the read
operation and the data will be undefined. After the latch command is
specified in the Mode register, the present value of the Down Counter
is latched into the Count Latch. This value remains in the latch until it
is read by the CPU or the counter/timer is reinitialized. More than one
latch command can be used to latch more than one counter/timer at a
time.
The count latched at the time of a latch command will not be changed
if a second latch command is specified for the same counter/timer
before the count is read by the CPU.
The count must be read according to the programmed Read/Write
Mode. If the Read/Write Mode specifies two-byte operation, two read
operations from the Count register are required, the first for the low
byte and the second for the high byte. If the Read/Write Mode is not
programmed for two-byte operation, only one read operation is
needed.
7-14
Counter/Timers
Multiple Latch Command
The Multiple Latch command extends the capabilities of the Count
Latch command. The Multiple Latch command is used to selectively
latch the count and status of any or all counter/timers simultaneously.
This command is the only method of reading the status of a
counter/timer.
Once the status or count is latched with this command, it is unaffected
by further latch commands. The latched data must be read or the
counter/timer reinitialized before the Count Latch and Status Latch
will resume tracking the operation of the Down Counter.
The count and status must be read according to the Read/Write Mode
programmed for the selected counter/timer. Two read operations are
required if the Read/Write Mode specifies two-byte operation and the
status is not latched. The first read is for the low byte of the count and
the second for the high byte. If the status is latched, three read
operations are required with the status being the first byte read,
followed by the low and then the high bytes of the count. One read
operation is all that is needed for single-byte mode, if the status is not
latched. For single-byte operations with latched status, two read
operations are needed, the first for the status and the second for the
data.
7-15
Counter/Timers
Modes of Operation
There are six possible count modes for the counter/timers. There are
restrictions for counter/timers 0 and 1 because the control inputs are
not available externally.
Mode 0 - Interrupt on Count Termination
In Mode 0 operation, the counter/timers count down the programmed
number of counts and transition the output signal. This mode is
commonly used to count external events. Counter/timer 2 fully
supports this mode with the TCTL input available through connector
J3 of the ZT 8832. Timer/counters 0 and 1 support Mode 0 with the
exception of the TCTL input signal.
Examples of Mode 0 operation are shown in Figure 7-7. TOUT
remains low until the Down Counter reaches zero, at which point
TOUT returns high. TOUT stays high until the Count or Mode
registers are reprogrammed.
CLK
COUNT = 0003H
IOWR
(Internal)
TOUT2
Count value
IOWR
?
?
0003H
COUNT = 0003H
0002H
0001H
0000H
FFFFH FFFEH FFFDH FFFCH FFFBH
COUNT = 0004H
(Internal)
TOUT2
Count value
?
?
0003H
0002H
0004H
0003H
0002H
0001H
0000H
FFFFH FFFEH
0003H
0002H
0002H
0001H
0000H
FFFFH FFFEH FFFDH FFFCH
COUNT = 0003H
IOWR
(Internal)
TCTL2
TOUT2
Count value
?
?
Figure 7–7. Mode 0 Operation.
7-16
Counter/Timers
The TCTL signal is used to enable and disable the counting operation.
The counting operation is enabled if TCTL is high and disabled if
TCTL is low. TCTL has no effect on the TOUT signal.
The Down Counter does not begin decrementing until the clock pulse
after the count is programmed. This is because it takes one clock
pulse to transfer the count from the Count register to the Down
Counter. This means that for an initial count of N, TOUT does not
transition high until N + 1 clock pulses later.
If a new count is written to the counter/timer before the previous
count is decremented to zero, the Down Counter begins counting from
the new count after the next clock pulse. If the count is two bytes
long, the first byte disables counting and lowers TOUT. Not until one
clock pulse after the second byte is programmed will the entire count
be transferred to the Down Counter.
It is possible to start the Down Counter with the TCTL signal by
programming the initial count with TCTL low. The programmed
count will be transferred to from the Count register to the Down
Counter on the next clock pulse. TOUT will not go low until N clock
pulses after TCTL goes high.
7-17
Counter/Timers
Mode 1 - Retriggerable One-Shot
In Mode 1, counter/timer 2 is triggered to generate a pulse of
programmed length. Applications can use this mode to signal the
occurrence of a single external event without having to monitor for a
change in count. This mode is supported only by counter/timer 2.
Examples of Mode 1 operation are shown in Figure 7-8. TOUT is
high until one clock pulse after TCTL triggers the count operation to
start. This is the start of the one-shot pulse. The pulse terminates by
lowering TOUT after the count reaches zero. TOUT remains low
until one clock pulse following the next TCTL trigger.
The Down Counter is armed after the Mode and Count are
programmed. A TCTL trigger transfers the count from the Count
register to the Down Counter and lowers TOUT on the next clock
pulse. This means an initial count of N results in a low level pulse
duration of N clock pulses. Since the one-shot is retriggerable, TOUT
remains low for N clock pulses after any trigger.
Programming the counter/timer with a new count does not affect the
current pulse width unless a TCTL trigger occurs. If this happens, the
new count is transferred to the Down Counter and the TOUT signal
remains low for the new number of programmed clock pulses.
7-18
Counter/Timers
CLK
COUNT = 0002H
IOWR
(Internal)
TCTL2
TOUT2
Count value
?
?
?
IOWR COUNT = 0005H
0002H
0001H
0000H
FFFFH
0002H
0001H
0002H
0003H
0002H
0000H
FFFFH
COUNT = 0003H
(Internal)
TCTL2
TOUT2
Count value
?
?
?
0005H
0004H
0003H
0001H 0000H
Figure 7–8. Mode 1 Operation.
7-19
Counter/Timers
Mode 2 - Rate Generator
The output of a counter/timer in Mode 2 is high until the programmed
count reaches one, then pulses low for a single count before returning
to a high value and repeating the operation.
Counter/timer 2 fully supports Mode 2 operation with TCTL available
through connector J3 of the ZT 8832. Counter/timers 0 and 1 support
Mode 2 with the exception of the TCTL input. The output of
counter/timer 0 is connected to INT1 of the interrupt controller, which
makes it the first choice for generating periodic interrupts. The output
of counter/timer 1 can be connected to INT2 of the interrupt controller
by programming the OPCN V40 configuration register. Counter/timer
1 should be used to generate periodic interrupts only when the V40
serial controller is not needed.
Figure 7-9 includes examples of Mode 2 operation. TOUT remains
high until the programmed number of counts is decremented to one.
At this point, TOUT transitions low for only one clock pulse. As
TOUT becomes high, the Down Counter is reloaded automatically
and the process is repeated. The entire cycle is periodic, with a period
of N clock cycles, for an initial count of N.
The TCTL signal provides a means of stopping the Down Counter for
counter/timer 2 only. If TCTL is high, the operation continues as
defined above. If TCTL is lowered during the count operation, the
Down Counter stops and the TOUT signal is immediately set high. A
TCTL trigger causes the count to be transferred from the Count Latch
to the Down Counter, and operation to be resumed.
Programming the Count register with a new count while the Down
Counter is counting does not affect the current counting sequence.
The new count will be loaded automatically after the current cycle is
completed, or on the occurrence of a TCTL trigger.
7-20
Counter/Timers
CLK
COUNT = 0003H
IOWR
(Internal)
TCTL2
TOUT2
Count value
?
?
0003H
0002H
IOWR COUNT = 0006H
0001H
0003H
0002H
0002H
0003H 0002H
0001H
0004H
0001H
COUNT = 0004H
(Internal)
TOUT2
Count value
?
?
0006H
0005H
0004H
0003H
0002H
0003H 0002H
Figure 7–9. Mode 2 Operation.
7-21
Counter/Timers
Mode 3 - Square Wave Generator
The most common use for Mode 3 is baud rate generation. The V40
Serial Control Unit requires that counter/timer 1 be configured in
Mode 3 to provide the serial transmit and receive clock. The only
difference between Mode 2 and Mode 3 is the duty cycle of the
counter/timer output. In Mode 2, the output pulses low for the last
count, while in Mode 3 the output is low for half of the programmed
count. All counter/timers support Mode 3 with the exception that
counter/timers 0 and 1 do not have a TCTL input. The TCTL input
for counter/timer 2 is available through connector J3 of the ZT 8832.
Refer to Figure 7-10 for examples of Mode 3 operation. The TOUT
signal remains high until the programmed number of counts is
decremented by half. TOUT then goes low for the remainder of the
count. The entire operation is periodic because it repeats
automatically. An initial count of N produces a square wave with a
period of N clock cycles.
The TCTL signal provides a means of suspending the Down Counter
for counter/timer 2 only. If TCTL is high, the operation continues as
defined above. If TCTL is lowered during the count operation, the
Down Counter stops and the TOUT signal is immediately set high. A
TCTL trigger causes the count to be transferred from the Count Latch
to the Down Counter, and counting to resume.
The operation of the Down Counter is not affected if a new count is
written while it is counting. The new count will be loaded into the
Down Counter at the end of the current half-cycle or after a TCTL
trigger.
7-22
Counter/Timers
Actual counter operation is different for even and odd counts. For
even counts, the initial count is loaded in one clock pulse and
decremented by two on succeeding clock pulses. TOUT changes state
when the count expires and the operation is repeated. For odd counts,
the initial count minus one is loaded in one clock pulse and
decremented by two on succeeding clock pulses. TOUT goes low one
clock pulse after the count expires and the operation is repeated. For
an odd count of N, TOUT is high for (N + 1)/2 and low for (N -1)/2.
CLK
COUNT = 0004H
IOWR
(Internal)
TCTL2
TOUT2
Count value
?
?
0004H
0002H
0004H
0002H
0004H
0002H
0004H 0004H
0004H
0002H
0000H
0004H
0002H
0004H
0002H
0004H
IOWR COUNT = 0005H
(Internal)
TOUT2
Count value
?
?
0000H 0004H
Figure 7–10. Mode 3 Operation.
7-23
Counter/Timers
Mode 4 - Software Triggered Strobe
Mode 4 operation provides a means of generating a hardware delay
triggered by software. Counter/timer 2 fully supports Mode 4
operation with the TCTL input available through connector J3 of the
ZT 8832. Counter/timers 0 and 1 support Mode 4 with the exception
of the TCTL input signal.
Examples of Mode 4 operation are included in Figure 7-11. Counting
begins automatically one clock pulse after the count is programmed.
TOUT remains high until the count reaches zero. At a count of zero,
TOUT goes low for one clock pulse and returns high. The count is not
decremented until after it is transferred to the Down Counter by the
first clock pulse. This means TOUT does not go low until N + 1 clock
pulses later, for an initial count of N.
The TCTL signal can be used to stop the Down Counter for
counter/timer 2. A high TCTL signal enables counting and a low on
TCTL stops it. TOUT is not affected by TCTL.
A new count can be written to the counter/timer while it is counting.
The new count will be transferred to the Down Counter on the next
clock pulse and counting will continue from the new value. A twobyte count will not be transferred to the Down Counter until the
second byte is written.
7-24
Counter/Timers
CLK
COUNT = 4
IOWR
(Internal)
TOUT2
Count value
?
?
0004H
0003H
0002H
0001H
0000H
FFFFH FFFEH FFFDH FFFCH
?
?
0004H
0004H
0004H
0003H
0002H
0001H
0000H
FFFFH FFFEH
0003H
0002H
0001H
0000H FFFFH
IOWR
(Internal)
TCTL2
TOUT2
Count value
IOWR
COUNT = 5
COUNT = 3
(Internal)
TOUT2
Count value
?
?
0005H
0004H
0003H
0002H
Figure 7–11. Mode 4 Operation.
7-25
Counter/Timers
Mode 5 - Hardware Triggered Strobe
Mode 5 operation provides a means of generating a hardware delay
triggered by a hardware signal. This mode is similar to Mode 4 except
for the counting process, which is started by a signal external to the
ZT 8832. Counter/timer 2 is the only one that supports Mode 5.
Examples of Mode 5 operation are illustrated in Figure 7-12. A TCTL
trigger transfers the programmed count from the Count Latch to the
Down Counter and starts the counting process. The TOUT signal
remains until the count reaches zero. At a count of zero, TOUT goes
low for one clock pulse before returning high. It takes one clock pulse
to transfer the initial count from the Count Latch to the Down
Counter. This means for an initial count of N, TOUT will not go low
until N + 1 clock pulses after the TCTL trigger.
The counting sequence can be retriggered at any time with TCTL. If a
TCTL trigger occurs while the Down Counter is operating, the
programmed count is transferred to the Down Counter on the next
clock pulse and counting starts over. Writing a new count will not
affect counter/timer operation. If a TCTL trigger occurs after a new
count is programmed but before the current count expires, the new
count will be loaded and counting will begin at this new value.
7-26
Counter/Timers
CLK
COUNT = 0002h
IOWR
(Internal)
TCTL2
TOUT2
Count value
IOWR
?
?
?
COUNT = 0004h
0002h
0001h
0000h
FFFFh
0002h
0001h
0002h
FFFFh
FFFEh
0001h
COUNT = 0003h
(Internal)
TCTL2
TOUT2
Count value
?
?
?
0004h
0003h
0002h
0001h
0000h
0003h
Figure 7–12. Mode 5 Operation.
7-27
Counter/Timers
Programming
The TCU is enabled and mapped into an I/O address range using the
V40 configuration register. The TCU includes three counter/timers
and four programmable registers. The first register to be programmed
is the Mode register. This register selects one of the three
counter/timers and information needed for initialization. The next
register to be programmed is the Count register for the counter/timer
being used. When programming the Count register, it is important to
always write the number of bytes specified in the Read/Write Mode
bits of the Mode register.
The Count Latch and Multiple Count Latch commands are
recommended for reading count data from the Status register. When
reading the count, the number of bytes read must be consistent with
the Read/Write Mode bits programmed to the counter/timer. The low
byte is transferred on the first read operation of a two-byte read. The
Multiple Latch command must be used to read the status. If the count
and status are latched with the Multiple Latch command, add one to
the number of reads defined by the Read/Write Mode for the status.
As an example, if the Read/Write Mode specifies two bytes, three
read operations are required: one for the status, one for the low byte
of the count, and one for the high byte of the count, respectively.
7-28
Chapter 8
INTERRUPT CONTROLLER (V40)
Contents
Page
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2
ZT 8832 SPECIFICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3
FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
Interrupt Request Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
Interrupt Mask Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
Priority Resolver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
Interrupt In-Service Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
Control Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6
Read/Write Control Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6
Initialization and Operation Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6
PROGRAMMABLE REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-7
Initialization Words (IIW1, IIW2, IIW3, and IIW4) . . . . . . . . . . . . . . . 8-8
Operation Words (IMKW, IPFW, and IMDW) . . . . . . . . . . . . . . . . . . 8-12
Status Words (IRQ, IIS, and IPOL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-16
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-19
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-19
Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-19
Interrupt Vectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-21
Interrupt Nesting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-22
Level- or Edge-Triggered . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-25
Finish Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-26
Automatic Priority Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-28
Specific Priority Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-29
Interrupt Masking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-30
Interrupt Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-31
Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-31
8-1
Interrupt Controller (V40)
OVERVIEW
This chapter describes the Interrupt Control Unit (ICU) and provides
register descriptions.
The ICU is a programmable interface between interrupt-generating
peripherals and the CPU. The ICU monitors eight interrupt inputs
with programmable priority. When peripherals request service, the
ICU interrupts the CPU with a pointer to a service routine for the
highest priority device. This type of interrupt management is needed
for an efficient interface between the CPU and supporting peripheral
devices, such as serial controllers and counter/timers. The major
features of the ICU are as follows:
•
Eight individually maskable interrupts
•
Level- or edge-triggered interrupts
•
Fixed and rotating prioritization
•
Status available for polled operation
•
Functionally equivalent to the 8259
8-2
Interrupt Controller (V40)
ZT 8832 SPECIFICS
The inputs to the interrupt controller are connected as shown in
Table 8-1.
Table 8-1
Interrupt Controller Inputs.
Input
Connection
IRQ0
IRQ1
IRQ2
Counter/timer 0 output
V40 serial port or watchdog timer stage 1
Counter/timer 1 output
or SBX expansion module interrupt 0
SBX expansion module interrupt 1
82050 serial port
STD bus control port
Connector J3 pin 8
Connector J3 pin 10
IRQ3
IRQ4
IRQ5
IRQ6
IRQ7
The interrupt controller includes a cascade mode not supported by the
ZT 8832. Cascade mode is a scheme to expand the number of
interrupt request inputs by connecting seven slave interrupt controllers
to the inputs of a master interrupt controller. In this scheme, the
master interrupt controller must provide a cascade address to the slave
controllers during interrupt acknowledge. The cascade address is not
provided by the ZT 8832.
8-3
Interrupt Controller (V40)
FUNCTIONAL DESCRIPTION
The format of the ICU programmable registers is the same as the
industry standard 8259 Programmable Interrupt Controller, with one
exception: 8085 operation is not supported. The ICU can be divided
into seven functional blocks as shown in Figure 8-1.
IORD
IOWR
A2
A1
EN
Read/
Write
Control
Initialization and
Operation Registers
INTAK
INTRQ
Control Logic
Priority
Determination
Logic
Interrupt
Request
Register
(IRQ)
Interrupt
In-Service
Register
(IIS)
Interrupt
Mask
Register
(IMK)
0
IRQ0
1
IRQ1
2
IRQ2
3
IRQ3
4
IRQ4
5
IRQ5
6
IRQ6
7
IRQ7
Internal Data Bus Lower 8 Bits
[1] See Jumper Configuration tables for signal selection information.
Figure 8–1. ICU Block Diagram.
Interrupt Request Register
The eight interrupt requests, IRQ0 through IRQ7, are input to the
Interrupt Request register. The 8-bit IRQ register maintains a bit
position for each interrupt input. A requesting interrupt sets the bit
position to a logical 1. The bit is automatically reset during the
interrupt acknowledge cycle. The IRQ register can be read by the
application program to determine the status of the requesting
interrupts.
8-4
Interrupt Controller (V40)
Interrupt Mask Register
All interrupt requests are latched by the Interrupt Request register.
The Interrupt Mask register acts as a programmable filter to
selectively disable requesting interrupts from being serviced. The
IMK is an 8-bit register with one bit position for each interrupt input.
Setting a bit to a logical 1 prevents the respective interrupt request
from being transferred from the Interrupt Request register to the
Interrupt In-Service register.
Priority Resolver
All interrupt requests are latched into the Interrupt Request register.
Those not masked by the Interrupt Mask register are input to the
Priority Resolver to determine which is to be serviced. The interrupt
request with the highest priority is transferred from the Interrupt
Request register to the Interrupt In-Service register during the
interrupt acknowledge cycle. The ICU includes several programmable
operating modes that define the rules by which the Priority Resolver
determines the highest priority interrupt request. These modes range
from all inputs having equal priority to rotating the priorities each
time an interrupt is serviced.
Interrupt In-Service Register
The 8-bit Interrupt In-Service register maintains a bit position for each
interrupt request that is currently being serviced. More than one bit
can be set if an interrupt is currently under service and a second
interrupt request is acknowledged. The IIS register is read to
determine the status of the interrupts currently being serviced. A
logical 1 in a bit position means that the interrupt is currently being
serviced.
8-5
Interrupt Controller (V40)
Control Logic
This functional block directs the operation of the other ICU blocks
based on the programmed mode of operation. The Control Logic also
interfaces to the CPU for interrupt request and acknowledge signals.
An interrupt request is generated to the CPU if an ICU input has the
correct priority and is not masked. If the CPU interrupts have been
enabled with the "set interrupt" command, it will respond with an
interrupt acknowledge.
Read/Write Control Logic
The Read/Write Control Logic controls command and data transfer
between the ICU and the CPU. This functional block selects an ICU
register and determines the direction of data travel based on the
address and I/O control inputs.
Initialization and Operation Registers
The ICU is programmable to provide flexibility in the way interrupts
are handled. The ICU is initialized by writing up to four 8-bit values
called Interrupt Initialization Word 1 through Interrupt Initialization
Word 4. Once initialized, the operation of the ICU is controlled with
three 8-bit values called Interrupt Mask Word, Interrupt Priority and
Finish Word, and Interrupt Mode Word.
8-6
Interrupt Controller (V40)
PROGRAMMABLE REGISTERS
The ICU is initialized with Interrupt Initialization Word 1 (IIW1)
through Interrupt Initialization Word 4 (IIW4). Once initialized, the
operation of the ICU is controlled with the Interrupt Mask Word
(IMKW), Interrupt Priority and Finish Word (IPFW), and Interrupt
Mode Word (IMDW). Three status words can also be read to
interrogate the operation of the ICU: the Interrupt Request (IRQ),
Interrupt In-Service (IISI), and Interrupt Poll (IPOL). Note that the
"word" reference does not mean the values are 16 bits; all
communication to the ICU is done through 8-bit data.
All initialization, operation, and status words are accessed through
two I/O addresses, as shown in Table 8-2. As might be expected, a
specific sequence of read and write operations is needed to pass
multiple bytes through a single I/O address. A complete description of
all the programmable words and how they are accessed is given on the
following pages.
Table 8-2
ICU Register Addressing.
Address
Value
Operation
Page Number
Base + 0
Base + 0
Base + 0
Base + 1
Base + 1
IRQ, IIS, IPOL
IIW1
IMDW, IPFW
IMKW
IIW2, IIW3, IIW4
Read
Write
Write
Read/Write
Write
8-16
8-8
8-13,8-15
8-12
8-8
8-7
Interrupt Controller (V40)
Initialization Words (IIW1, IIW2, IIW3, and IIW4)
The ICU must be initialized before it can be used. Initialization
consists of writing from two to four bytes called interrupt
initialization words.
The sequence in which these words are programmed is outlined in the
flow chart shown in Figure 8-2. IIW1 and IIW2 must be programmed
during any initialization sequence. IIW3 is not supported by the
ZT 8832 and should be initialized to zero. IIW4 may or may not be
programmed as required by the application. The ICU decodes the first
two bits of IIW1 to know whether or not to expect IIW4 and IIW3,
respectively.
IIW1
Base Address +0
IIW2
Base Address +1
IIW1 Bit0=1
IIW1 Bit1=0
IIW1 Bit0=0
IIW1 Bit1=0
IIW1 Bit0=1
IIW1 Bit1=1
IIW3
Base Address +1
IIW3=0
IIW4
Base Address +1
Base Address +1
IIW4
Base Address +1
Initialization
Complete
Figure 8–2. Interrupt Initialization Programming.
8-8
IIW1 Bit0=0
IIW1 Bit1=1
Interrupt Controller (V40)
IIW1 and IIW2
Interrupt Initialization Words 1 (IIW1) and 2 (IIW2) are required
for ICU initialization. The IIW1 register, shown in Figure 8-3, is
divided into two fields labeled II4 (Interrupt Initialization 4) and
LEV (Level). The II4 bit selects whether or not the IIW4 register
is to be programmed. If II4 is set to a logical 1, the ICU expects
IIW4 to be written as part of the initialization. The LEV bit of
IIW1 selects between level- or edge-triggered interrupt request
inputs. Setting LEV to a logical 1 selects level-triggered inputs,
while a logical 0 selects edge-triggered.
7
6
5
4
3
2
1
0
—
—
—
1
LEV
—
1
II4
IIW1
Address: Base + 0
Access: Write
Writes IIW4
0 IIW4 not required
1 IIW4 required
Level-Triggered Mode
0 Edge-triggered
1 Level-triggered
Figure 8–3. Interrupt Initialization Word 1.
8-9
Interrupt Controller (V40)
The ICU responds to an interrupt acknowledge by supplying the
CPU with an interrupt vector based on which interrupt generated
the request and the value programmed into IIW2. The format for
IIW2 is shown in Figure 8-4. Bits V3 through V7 define the upper
5 bits of the vector address.
7
6
5
4
3
2
1
0
V7
V6
V5
V4
V3
—
—
—
IIW2
Address: Base + 1
Access: Write
Higher 5 bits of
interrupt vector number
Figure 8–4. Interrupt Initialization Word 2.
IIW3
The ZT 8832 does not support cascading the interrupt controller
inputs to other interrupt controllers. Bits 0 through 7 must be programmed with logical 0s, as shown in Figure 8-5.
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
IIW3
Address: Base + 1
Access: Write
Figure 8–5. Interrupt Initialization Word 3.
8-10
Interrupt Controller (V40)
IIW4
Figure 8-6 shows the architecture for IIW4. IIW1 must be programmed with a logical 1 in the II4 bit if IIW4 is used. A logical
1 in the SFI bit enables the Self Finish Interrupt and a logical 0
disables it. The interrupt service routine must include an EOI
command when the Self Finish Interrupt is disabled.
7
6
5
4
3
2
1
0
0
0
0
0
—
—
SFI
1
IIW4
Address: Base + 1
Access: Write
Self Finish Interrupt
0 Finish interrupt
1 Self finish interrupt
Figure 8–6. Interrupt Initialization Word 4.
8-11
Interrupt Controller (V40)
Operation Words (IMKW, IPFW, and IMDW)
Once initialized, the operation of the ICU is controlled with three
8-bit values called the Interrupt Mask Word (IMKW), Interrupt
Priority and Finish Word (IPFW), and the Interrupt Mode Word
(IMDW). The Operation Words can be transferred in any sequence to
perform such functions as enabling and disabling individual interrupt
requests and changing interrupt priorities.
IMKW
The IMKW masks interrupt request inputs. Interrupts are masked
by writing IMKW to the IMK register. IMKW can be read
directly from the IMK register to determine the current status of
the mask. This eliminates the need for application software to
maintain a copy of the mask in program memory.
As shown in Figure 8-7, each of the eight bits in IMKW represents an interrupt input. Bit M0 is used to mask IRQ0, M1 is used
to mask IRQ1, and so on. Setting a bit in IMKW to a logical 1
prevents the interrupt request for the respective input from being
acknowledged by the ICU. The interrupt request is latched in the
IRQ register but it never reaches the IIS register.
7
6
5
4
3
2
1
M7
M6
M5
M4
M3
M2
M1
0
IMKW
Address: Base + 1
M0
Access: Read/Write
Interrupt Request Mask
Each bit:
0 IRQn not masked
1 IRQn masked
Figure 8–7. Interrupt Mask Word.
8-12
Interrupt Controller (V40)
IPFW
IPFW selects fixed or rotating priorities and the method of
informing the ICU that an interrupt has been serviced. Operation
of the ICU can be changed at any time by writing a new IPFW.
Refer to Figure 8-8 when programming the IPFW.
7
6
5
4
3
2
1
0
RP SIL FI
0
0
IL2 IL1 IL0
IPFW
Address: Base + 0
Access: Write
Requesting Input
000 INT0
001 INT1
010 INT2
011 INT3
100 INT4
101 INT5
110 INT6
111 INT7
End of Interrupt
001 Non-specific FI
011 Specific FI
Automatic Rotation
101 Rotate on non-specific FI
100 Rotate in auto FI (SET)
000 Rotate in auto FI (CLR)
Specific Rotation
111 Rotate on specific FI
110 Set priority command
010 No operation (do not use)
Figure 8–8. Interrupt Priority and Finish Word.
8-13
Interrupt Controller (V40)
The IL0 through IL2 bits designate an interrupt level. This level
is used by certain combinations of the FI, SIL, and RP bits either
to reset an interrupt request that has been recognized or to set a
specific priority.
The ICU uses the IIS register to keep track of which interrupts are
being serviced and their relative priorities. The ICU updates the
IIS register based on a Finish Interrupt command. There are three
methods of generating the finish interrupt command: specific FI,
nonspecific FI, and automatic FI. The automatic FI is
programmed with IIW4. The specific and nonspecific FI are
selected with the FI bit. A logical 1 in FI enables the specific or
nonspecific FI, based on the SIL and RP bits.
The SIL bit enables bits IL0 through IL2 for selected operations.
IL0 through IL2 indicate an interrupt level to be reset during the
finish interrupt commands or a new priority for priority rotation
commands.
The ICU provides several methods of establishing priorities for
the interrupt request inputs. The RP bit selects the priority
rotation options. A logical 1 in the RP bit indicates that rotation in
priorities is to take place based on the values of the FI and SIL
bits. A logical 0 in the RP bit means that no priority rotation will
take place.
8-14
Interrupt Controller (V40)
IMDW
IMDW controls the method of reading status from the ICU and
enables a special type of interrupt masking.
The format of the IMDW is shown in Figure 8-9. The first two
bits are used to select the IRQ and IIS registers so they can be
read by the application software. A logical 1 in bit 0 selects the
IIS register and a logical 0 selects the IRQ register. A logical 1 in
the SR bit (bit 1) enables the reading of the IRQ and IIS registers.
7
6
5
— SNM EXCN
4
3
0
1
2
1
0
POL SR IS/SR
IMDW
Address: Base + 0
Access: Write
Register Select
00 No operation
01 No operation
10 Int. Request (IRQ) selected
11 Int. In Service (IIS) selected
Polled Status
0 No operation
1 Polling command
Nesting Mode 2
01 No operation
10 Exceptional nesting mode
release
11 Exceptional nesting mode
set
Figure 8–9. Interrupt Mode Word.
8-15
Interrupt Controller (V40)
The POL bit selects the poll command. The two most commonly
used methods of servicing peripherals in a microprocessor system
are polling and interrupts. Although interrupts are the fastest
method of servicing peripherals, using the ICU in a polled
operation is still faster than polling each peripheral one at a time.
Setting the POL bit to a logical 1 enables the reading of the poll
status. The POL bit overrides the SR bit if both are set.
The EXCN and SNM bits can be programmed to enable or
disable the exceptional nesting mode of operation. The exceptional nesting mode is armed by setting SNM (bit 6) to a logical 1. The EXCN bit (bit 5) can then be used to set or release the
exceptional nesting mode. This operating mode is used to permit
interrupts of lower priority than the one currently under service to
be recognized.
Status Words (IRQ, IIS, and IPOL)
Three 8-bit status words can be read from the ICU. These are the
Interrupt Request (IRQ), Interrupt In-Service (IIS), and Interrupt Poll
(IPOL). These words can be read at any time by programming the
first three bits of the IMDW. Once the IMDW is programmed to
select one of the status words, that word can be read as many times as
needed. The IMDW must be programmed with a new value to read
another of the status words. The formats of the IRQ, IIS, and IPOL
are illustrated on the following pages.
8-16
Interrupt Controller (V40)
IRQ and IIS
The IRQ and IIS status words, shown in Figure 8-10 below, are
taken directly from the Interrupt Request register and Interrupt InService register, respectively. The IRQ status word contains all
the interrupt levels requesting service. The IIS status word
contains all the interrupt levels currently being serviced. Bit 0 of
both status words corresponds to IRQ0, bit 1 corresponds to
IRQ1, and so on.
7
6
5
4
3
2
IR7
IR6
IR5
IR4
IR3
IR2
1
0
IR1 IR0
Register:IRQ
Address:Base + 0
Access:Read
Request Level/Status
0 No request
1 Request
7
6
5
4
3
2
IR7
IR6
IR5
IR4
IR3
IR2
1
0
IR1 IR0
Register:IIS
Address:Base + 0
Access:Read
In-Service Level/Status
0 Not in service
1 In service
Figure 8–10. Interrupt Status Registers IRQ and IIS.
IPOL
The two most common methods of servicing peripherals in most
applications are polling and interrupts. Although the ICU is
designed primarily for interrupt control, it can be used in a polled
system to increase the efficiency of servicing peripherals. The
efficiency is increased because the CPU can poll the ICU to
determine the status of several peripheral devices at one time.
8-17
Interrupt Controller (V40)
Figure 8-11 shows the IPOL status word. Bits PL0 through PL2
define the highest priority interrupt input requesting service. For
example, if all three bits are set to a logical 1, then IRQ7 is the
highest priority request.
The INT bit (bit 7) indicates whether there are any interrupt
requests. A logical 1 signals an interrupt request and a logical 0
signals no interrupt request. If INT is a logical 0, PL0 through
PL2 are all set to a logical 1. The typical polling sequence is to
set the POL bit in IMDW, read the IPOL register, and test the
INT bit. If INT is a logical 1, decode PL0 through PL2 to
determine which peripheral to service.
7
6
5
4
3
INT
0
0
0
0
2
1
0
PL2 PL1 PL0
Register:IPOL
Address:Base + 0
Access:Read
Highest Active Request
000 IRQ0
001 IRQ1
010 IRQ2
011 IRQ3
100 IRQ4
101 IRQ5
110 IRQ6
111 IRQ7
Interrupt
0 No interrupt present
1 Interrupt present
Figure 8–11. Interrupt Status Register IPOL.
8-18
Interrupt Controller (V40)
OPERATION
Reset
The ICU registers are not initialized to a default state when power is
applied to the ZT 8832 or after a reset. The OPCN V40 configuration
register is initialized to disable the ICU, which disables interrupts.
Interrupts
Most microprocessor systems include peripheral devices designed to
perform specific tasks. Examples include counter/timers, serial
controllers, and real-time clocks. The CPU has the job of managing
the peripherals to meet the needs of specific applications. One method
of peripheral management is for the CPU to start them on a job and
periodically poll for completion. The problem with this method is that
the overhead associated with polling reduces system throughput. As
the number of peripheral devices increases, so does the amount of
time spent polling. Interrupts provide the peripheral device with a
method of informing the CPU when it is ready to be serviced. The
following discussion explains how interrupting peripherals are
serviced in a V40-based system.
A peripheral device needing service generates an interrupt request on
one of the inputs to the ICU. The ICU responds by interrupting the
CPU if the incoming interrupt is not masked and has the highest
priority. Interrupt masking and priorities are explained later in this
section. Interrupts must be enabled in the CPU before the CPU can
recognize the interrupt request from the ICU. The CPU interrupts are
disabled after reset and must be enabled using the "set interrupt"
instruction. The CPU recognizes interrupts by storing the current
program location (Instruction Pointer and Program Segment) and
status (Processor Status Word) on the stack and entering an interrupt
acknowledge cycle. The current program location and status are
preserved on the stack as a return pointer that allows program
execution to continue after the interrupt is serviced.
8-19
Interrupt Controller (V40)
The V40 interrupt acknowledge cycle is two machine cycles long and
looks much the same as two I/O read cycles. The difference is that the
CPU interrupt acknowledge signal is pulsed low for two clock periods
each machine cycle instead of the read signal. The first interrupt
acknowledge pulse prepares the ICU to provide an interrupt vector on
the second. Preparation includes freezing the state of the interrupts
internal to the ICU so the highest priority request can be determined.
The ICU supplies an interrupt vector onto the CPU data bus in
response to the second interrupt acknowledge pulse.
The interrupt vector is an 8-bit value used to point the CPU to an
interrupt service routine for the peripheral device being
acknowledged. A unique vector is generated by the ICU for each
interrupt request input. The CPU reads the vector from the data bus
and multiplies it by four to point to the address of the service routine.
The CPU then begins executing the interrupt service routine at this
address. See the following section, entitled "Interrupt Vectors," for
more information on the interrupt vector and how it relates to the
address of the service routine. The CPU automatically disables
interrupts at the start of the interrupt service routine and does not
enable them again until the interrupt service routine is completed.
This means the CPU will not acknowledge interrupt requests of a
higher priority from the ICU until it is finished servicing the current
request. The "clear interrupt" instruction can be used to enable
interrupts before completion of the current service routine.
The "return from interrupt" is the last instruction of the interrupt
service routine. This instruction enables interrupts and transfers
program execution back to the interrupted program by restoring the
Instruction Pointer, Program Segment, and Processor Status Word
from the stack.
8-20
Interrupt Controller (V40)
Interrupt Vectors
The CPU responds to all external interrupt requests by reading an
8-bit value from the interrupt device that indirectly points to the
subroutine used to service the device. The 8-bit value is called the
interrupt vector and the subroutine used to service the device is the
interrupt service routine.
The relationship between the interrupt vector provided by the ICU and
the address of the interrupt service routine is illustrated in Figure
8-12. The ICU provides a unique 8-bit vector for each interrupt input,
based on the IMKW value programmed. The CPU multiplies the
vector by four to point to the memory location that contains the
address of the service routine. The address of the interrupt service
routine includes the Instruction Pointer and Program Segment. The
application software must program the Instruction Pointer and
Program Segment into the appropriate memory locations before the
interrupt request is generated.
0
7
ICU
CPU
Programmed To
Provide Unique
Vector (N) For
Each Input
Multiplies Vector
(N) By Four
N
x4
4N
MEMORY
4N
4N+1
4N+2
4N+3
Offset
PFP (IP)
Segment
PS (CS)
Interrupt
Service
Routine
NMI (N=2)
Figure 8–12. CPU Interrupt Vector Processing.
8-21
Interrupt Controller (V40)
Interrupt Nesting
Interrupt nesting is a powerful structure that allows an interrupt
currently under service to be suspended while a second interrupt is
serviced. The ICU supports nested interrupts. In most cases, the
second interrupt must be a higher priority than the one currently being
serviced. The exceptions to the rule are listed below.
•
Any ICU using the Self Finish mode
•
Any ICU using the Exceptional Nesting mode
The best way to understand nested interrupts is to examine the
operation of the Interrupt Request (IRQ) and Interrupt In-Service (IIS)
registers when multiple interrupt requests are generated. A bit in the
IRQ register is set when an interrupt request is generated. More than
one bit of the IRQ register will be set if more than one request occurs
between interrupt acknowledge cycles. During the interrupt
acknowledge cycle, the highest priority request is selected from the
IRQ register and the vector for that request sent to the CPU. The
corresponding bit of the IIS register is also set to flag that the request
is currently being serviced. This bit remains set until a finish interrupt
command is sent to the ICU.
In nested operation, further requests of the same or lower priority are
inhibited while the IIS bit is set. A higher priority request can still
interrupt the CPU and vector program operation to its own service
routine if the "set interrupt" command is executed in the service
routine of the device currently being serviced.
An example of nested interrupt execution is illustrated in Figure 8-13.
This example assumes that the interrupt request inputs are prioritized
with IRQ0 having the highest priority and IRQ7 having the lowest.
The example begins in the main program. The "set interrupt"
command must be executed before an interrupt is recognized after
power on or reset. The CPU vectors program execution to the IRQ3
service routine in response to the IRQ3 request.
8-22
Interrupt Controller (V40)
Main Program
SI
IRQ3
Interrupt
...
IRQ3 Service
Routine
IRQ1
Interrupt
SI
IRQ1
Service
Routine
...
FI
FI
RET
RET
Figure 8–13. Nested Interrupt Structure.
8-23
Interrupt Controller (V40)
Next, an IRQ1 request occurs. Since interrupts are automatically
disabled upon entering a service routine, the IRQ1 request is not
acknowledged until the "set interrupt" command is executed. Note
that if a lower priority input such as IRQ4 generates a request, it will
not be serviced until all higher priority requests are serviced. The
CPU vectors program execution to the IRQ1 service routine.
At this point in the sequence, the IIS register has bits IRQ3 and IRQ1
set. This means that IRQ0 is the only input with a high enough
priority to generate a request to the CPU. The IRQ1 service routine is
terminated with the "finish interrupt" command. This command clears
the IRQ1 bit in the IIS register. The "interrupt return" instruction
vectors program execution back to the IRQ3 service routine. At this
point IRQ0 through IRQ2 have high enough priority to generate an
interrupt to the CPU. This routine is again completed with a "finish
interrupt" command and "interrupt return" instruction.
8-24
Interrupt Controller (V40)
Level- or Edge-Triggered
The two primary methods of sensing interrupt requests are to sense
the logical state (level) or the transition between logical states (edge)
of the interrupt request inputs. The ICU is programmed for level- or
edge-triggered interrupt sensing with the IIW1 register.
Level-Triggered Sensing
If programmed for level-triggered mode, the ICU recognizes a logical
1 as an interrupt request. There is a level of inversion between the
ICU and the interrupt request block. This means that all STD bus and
frontplane (J3) interrupt requests are active low.
There is a minimum and maximum pulse width for the interrupt
request input to guarantee proper operation. The minimum pulse
width requirement states that the request must remain active until the
falling edge of the second interrupt acknowledge pulse. The
maximum amount of time the request remains active is determined by
when the "finish interrupt" command is written. If the request remains
active after the "finish interrupt" command is issued, a second
interrupt is generated on the same request.
Edge-Triggered Sensing
Edge-triggering is the second mode of interrupt sensing. The ICU
recognizes a transition from a logical 0 to a logical 1 as an interrupt
request. There is a minimum pulse width for the interrupt request
input to guarantee proper operation. As in the level-triggered mode,
the request must remain active until the falling edge of the second
interrupt acknowledge pulse. Unlike the level-triggered mode, there is
no maximum pulse width. This means that once the request
transitions to the active state and is serviced, there are no further
interrupts generated until the request returns inactive and then
transitions back into the active state.
8-25
Interrupt Controller (V40)
Finish Interrupts
The ICU must be told when a service routine is completed so that the
in-service bit of the IIS register can be cleared. The three finish
interrupt formats that the ICU recognizes are the nonspecific finish
interrupt, specific finish interrupt, and automatic finish interrupt.
Nonspecific FI
The ICU accepts a nonspecific FI as an indication of interrupt service
completion of the highest priority request. The advantage of the finish
interrupt format is that you need not specify the level to be cleared.
The catch is that the nonspecific FI command must be used only in
operating modes in which the service routine of the highest priority
request is the first one completed. Two instances in which the
nonspecific FI command should not be used are if priorities are
changed during an interrupt service routine and if the exceptional
nesting mode is used.
Specific FI
The second finish interrupt format is the specific FI command. This
command includes the level of the request to be cleared. The specific
FI command must be used if the highest priority interrupt is not
always the first one completely serviced. Such is the case if the
interrupt priorities are changed during a service routine (called
specific rotation). If the nonspecific FI were used in this case, it is
possible that the wrong in-service bit might be reset by the ICU. The
specific FI can be used in all modes of ICU operation.
8-26
Interrupt Controller (V40)
Automatic Finish Interrupt
When programmed for automatic FI, the ICU automatically executes
a nonspecific FI during the interrupt acknowledge cycle. The
advantage of the finish interrupt format is that you need no longer
issue a command to the ICU that a service routine is completed. Like
the nonspecific FI, the automatic FI must be used only in operating
modes in which the service routine of the highest priority request is
the first one completed. Two instances in which the automatic FI
command should not be used are if priorities are changed during an
interrupt service routine and if the exceptional nesting mode is used.
When using the automatic FI format, you must disable interrupt
requests during the execution of an interrupt service routine. This is
because the IIS bit is cleared immediately after the interrupt
acknowledge cycle or, in other words, before the service routine is
started. If interrupts are enabled during the service routine, there is no
indication that an interrupt is currently being serviced, and a second
request can be generated by the same interrupt if level-triggered
interrupts are used. This can continue until the level is removed,
resulting in an undefined operation.
8-27
Interrupt Controller (V40)
Automatic Priority Rotation
Automatic priority rotation is used in applications with interrupt
devices that are of equal priority. In this mode of operation, after an
interrupt request is serviced the ICU rotates it into the lowest priority
slot. This guarantees that all interrupt requests will be serviced. The
nonspecific FI or specific FI commands can be used for automatic
priority rotation.
Rotate on Nonspecific FI
The ICU response to a rotate on nonspecific FI is the same as
previously discussed, except that the interrupt request is rotated into
the lowest priority position after the IIS bit of the Interrupt In-Service
is cleared. The other ICU inputs are also rotated into the next higher
priority position.
Rotate on Self Finish FI
The ICU handles a rotate on self finish FI in much the same manner
as the self finish FI previously discussed. The difference is that
priority rotation is done automatically after the IIS bit is reset. The
same precautions discussed under the self finish FI explanation still
apply.
8-28
Interrupt Controller (V40)
Specific Priority Rotation
Specific rotation, like automatic rotation, can be used to change the
priorities of the ICU inputs. With automatic rotation, the last request
serviced is rotated into the lowest priority, and other ICU inputs are
rotated up one level. With specific rotation, you specify which
interrupt receives the lowest or highest priority. Either the set priority
command or the rotate on specific FI command can be used to select
this operating mode.
Set Priority
The set priority command is used to define the priority of the ICU
inputs. You specify the lowest priority interrupt as part of the
command. If, for example, you define IRQ4 as part of the set priority
command, then IRQ3 is automatically the second lowest, IRQ2 the
third lowest, and so on up to IRQ5, which is the highest. The
nonspecific FI command must not be used with the set priority
command. This is because the nonspecific FI clears the highest
priority IIS bit, which is not the one most recently serviced if the set
priority command changed priorities. The self finish FI can be used
because it clears the IIS bit during the interrupt acknowledge cycle or,
in other words, before the set priority command can change the
priorities. The specific FI command is the simplest to use because the
level is not selected by the ICU, but specified by you.
Rotate on Specific FI
The rotate on specific FI command is a combination of the set priority
and the specific FI command. The command clears the ISR bit and
changes the priority of interrupt inputs, based on the specified level.
The primary advantage of this command is that it performs the
functions of two commands in one operation.
8-29
Interrupt Controller (V40)
Interrupt Masking
The ICU inputs are all maskable. The "clear interrupt" instruction can
be executed to disable all ICU inputs from generating interrupts. In
certain applications it may be necessary to disable, or mask, selected
ICU inputs. The ICU Interrupt Mask register (IMKW) includes one
bit for each ICU input to permit selective masking. An interrupt,
masked or not, flags a request by setting a bit in the IRQ register. If
the request is masked it is not passed to the IIS register until the mask
bit is cleared. If the interrupt input to the ICU is removed before the
mask bit is cleared, the IRQ bit is reset and the request is missed.
In certain instances it may be necessary to enable interrupts of a lower
priority than the one currently being serviced. The special mask mode
can be used to enable all levels of interrupts except the one being
serviced. The special mask mode is set and cleared using the IMDW
register. A non-specific FI must not be used if the ICU is programmed
for the special mask mode. This is because the nonspecific FI will not
clear an IIS bit if it is masked. It is best to use the specific FI
command when operating in the special mask mode.
8-30
Interrupt Controller (V40)
Interrupt Status
The Interrupt Request (IRQ), Interrupt In-Service (IIS), and Interrupt
Mask (IMKW) registers are available to the programmer. The IRQ
and IIS registers are read by first writing the appropriate read register
command to the ICU IMDW register. After the read register
command is written, the selected register can be read any number of
times. It is possible for an interrupt to occur after the read register
command is written to the IMDW register and before the selected
register is read. The interrupt service routine could alter the IMDW
register, causing the wrong register to be read. This is prevented by
disabling interrupts with the "disable interrupt" instruction before
programming the IMDW register, and not enabling them until after
reading the register. The IMKW register can be read directly from the
ICU without first writing to the IMDW register.
The ICU supports a polled operation for systems not wishing to use
interrupts. Although not as efficient as an interrupt-driven system, it is
more efficient than having to poll eight different I/O ports to see if a
peripheral is in need of servicing. To use the ICU in a polled mode,
the application program must not enable CPU interrupts. The ICU is
polled by first writing the poll command and then reading the IPOL
register.
Programming
The ICU is enabled and mapped into an I/O address range using the
V40 configuration registers. The ICU must be initialized with 2, 3, or
4 initialization control words before operation can begin. Once the
initialization control words have been programmed, ICU operation is
controlled by command words. The command words define the
operating mode and can be programmed at any time after
initialization.
8-31
Chapter 9
DMA CONTROLLER (V40)
Contents
Page
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-2
ZT 8832 SPECIFICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3
FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-4
Internal Bus Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5
Address Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5
Address Adjuster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5
Count Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-6
Count Adjuster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-6
Control Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-6
PROGRAMMABLE REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-7
DMA Initialize Command (DICM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-8
DMA Channel (DCH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-8
DMA Base Count/Current Count (DBC/DCC) . . . . . . . . . . . . . . . . . . 9-10
DMA Base Address/Current Address (DBA/DCA) . . . . . . . . . . . . . . 9-11
DMA Device Control (DDC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-12
DMA Mode (DMD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-13
DMA Status (DST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-15
DMA Mask (DMK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-16
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-17
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-17
Autoinitialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-18
Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-18
9-1
DMA Controller (V40)
OVERVIEW
This chapter describes the Direct Memory Access Control Unit
(DCU) and provides register descriptions.
The DCU is a programmable peripheral device used to direct high
speed data transfers between the ZT 8832 and SBX expansion module
I/O. The approximate data rate between the expansion module and
local RAM using standard input and output instructions is 235 Kbytes
per second. Using DMA, the data transfer rate is increased to approximately 1.3 Mbytes per second, for a performance increase of over 80
percent. DMA transfers to dual port RAM are slightly slower because
of arbitration time. If no dual port RAM accesses are made by the
STD bus CPU during the DMA operation, the data transfer rate is
approximately 1.1 Kbytes per second.
There are two primary reasons for this performance increase. The first
is that the DCU requires no instruction fetches to perform the data
transfer. All address manipulations are done with hardware internal to
the DCU, as opposed to the CPU having to fetch and execute the
address adjustment instructions. The second reason is that the DCU
transfers the data in one CPU machine cycle, rather than two. The
DCU allows data to travel from the source device through to the
destination device without temporarily storing it in a register, as is
done with the CPU.
The DCU has the following features:
•
1 Mbyte of direct memory addressability
•
Single, demand, and block data transfers
•
Autoinitialization
9-2
DMA Controller (V40)
ZT 8832 SPECIFICS
The ZT 8832 uses one of the four DMA controllers contained in the
V40. DMA channel 0 is used to coordinate high speed data transfers
between the SBX expansion module I/O and local or dual port
memory. The SBX expansion module must support DMA by driving
Expansion Module DMA Request (MDRQT) on J4 pin 34 and
receiving Expansion Module DMA Acknowledge (MDAK) on J4
pin 32. The DMA interface does not support Terminate DMA
(TDMA) on J4 pin 26.
To meet SBX expansion module timings, the WCY2 V40 configuration register must be must be programmed to insert two wait
states into DMA cycles. See page 6-7 for details.
9-3
DMA Controller (V40)
FUNCTIONAL DESCRIPTION
Figure 9-1 illustrates a block diagram of the DCU. The DCU is
divided into six major blocks for explanation purposes. Each of these
functional blocks is discussed below.
Address Adjuster
A0-A19
D0-D15
CONTROL
Internal Bus
Interface
Current Address
Control Registers
Base Address
Initialization
Address Register
BRQ
BAK
DRQ
DAK
Channel
Status
Mask
Device Control
Mode Control
Count Register
Current Count
Base Count
Count Adjuster
Figure 9–1. DCU Block Diagram.
9-4
DMA Controller (V40)
Internal Bus Interface
The Internal Bus Interface monitors address and data buses for
programming information. The Internal Bus Interface also generates
Bus Request (BRQ) to request access to the address, data, and control
buses in response to a DMA Request (DRQ) from the SBX expansion
module. The CPU acknowledges BRQ with Bus Acknowledge
(BAK), signaling the Internal Bus Interface to generate DMA
Acknowledge (DAK) to the SBX expansion module and perform the
data transfer.
Address Register
The Address register consists of a 20-bit base address and a 20-bit
current address. The base and current addresses are programmed with
the starting address of the memory block to be used in the transfer.
The memory is considered the source if the transfer is from ZT 8832
memory to the SBX expansion module. The memory is considered
the destination if the transfer is from the SBX expansion module to
the ZT 8832 memory. The current address is automatically adjusted
with hardware internal to the DCU as the transfers are made.
Address Adjuster
The Address Adjuster automatically updates the current address
register each time a data transfer is completed. The address register is
incremented or decremented by one for each byte transfer.
9-5
DMA Controller (V40)
Count Register
The Count register includes a 16-bit base count and a 16-bit current
count. The base count and current count are programmed with the
number of bytes to be transferred by the DMA operation. The base
count remains the same until a new count is specified. If the autoinitialize feature is used, the base count is transferred to the current
count when the count register is decremented to zero and the last
DMA operation is complete. The current count register is
decremented by one after each transfer to indicate the number of bytes
not yet transferred.
Count Adjuster
The Count Adjuster automatically updates the current count register
each time a data transfer is completed. The Count register is
incremented or decremented by one for each byte transfer.
Control Registers
The Control register functional block consists of six registers that are
used to control the DCU operation and provide DCU status. The
registers are explained in the following section.
9-6
DMA Controller (V40)
PROGRAMMABLE REGISTERS
The DCU occupies 16 consecutive I/O port addresses. Of those 16
addresses, 12 are used by the programmer to access DCU functions
and 4 are reserved. Table 9-1 lists the address of each of the registers
relative to a programmable base address. The base address is selected
with the OPHA and DULA V40 configuration registers; see page 6-5
for details.
Table 9-1
DCU Register Addressing.
Address
Register
Operation
Page Number
Base + 0
Base + 1
Base + 2
Base + 3
Base + 4
Base + 5
Base + 6
Base + 7
Base + 8
Base + 9
Base + A
Base + B
Base + C
Base + D
Base + E
Base + F
DICM
DCH
DBC/DCC-low
DBC/DCC-high
DBA/DCA-low
DBA/DCA-middle
DBA/DCA-high
Reserved
DDC-low
DDC-high
DMD
DST
Reserved
Reserved
Reserved
DMK
Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
-Read/Write
Read/Write
Read/Write
Read
---Read/Write
9-8
9-8
9-10
9-10
9-11
9-11
9-11
-9-12
9-12
9-13
9-15
---9-16
9-7
DMA Controller (V40)
DMA Initialize Command (DICM)
The initialization command, shown in Figure 9-2, includes one bit
that can be set to a logical 1 to reset the DCU. This register must be
written to with the byte output instruction.
7
6
5
4
3
2
1
0
—
—
—
—
—
—
0
RES
Register:DICM
Address:Base + 0
Access:Write Only
Reset
0 No reset
1 Reset
Figure 9–2. DMA Initialization Command Register.
DMA Channel (DCH)
The DMA Channel register, shown in Figure 9-3, must be accessed
with byte output and input instructions. The DCH register has a
different format for read and write operations. For the write operation,
the BASE bit is used to select between the base and current register
groups for both the address and count. Both base and current registers
are written or only the current register is read if BASE is first
programmed with a logical 0. Programming BASE with a logical 1
selects the base to be read or written to.
9-8
DMA Controller (V40)
For read operations, the BASE bit set to a logical 0 defines whether
the current register is made available for a read operation or whether
the base and current registers are written to during a write operation.
A logical 1 in the BASE bit means the base register is selected.
7
6
5
4
3
2
1
0
—
—
—
—
—
BASE
0
0
Register:DCH
Address:Base + 1
Access:Write Only
Base Only
0 Select current (read),
select both base
and current (write)
1 Select base (read/write)
7
6
5
4
—
—
— BASE
3
2
1
0
0
0
0
1
Register:DCH
Address:Base + 1
Access:Read Only
Base Only
0 Current (read), base
and current (write)
1 Base (read/write)
Figure 9–3. DMA Channel Register.
9-9
DMA Controller (V40)
DMA Base Count/Current Count (DBC/DCC)
Two DBC/DCC registers make up the 16-bit DMA count, as shown in
Figure 9-4. The two DBC/DCC registers can be accessed with byte or
word instructions. The function of these registers depends on the
BASE bit of the DCH register. If the BASE bit is set to a logical 0,
the values written to the Count registers are programmed into both
base and current count values. The current count is read from the
Count registers if the BASE bit is set to a logical 0. If the BASE bit is
set to a logical 1, the values written to the Count registers are
programmed into the base value only. The base value is read from the
Count registers if the BASE bit is set to a logical 1.
7
6
5
4
3
2
1
0
C7
C6
C5
C4
C3
C2
C1
C0
7
6
5
4
3
2
1
0
C9
C8
C15 C14 C13 C12 C11 C10
Register:DBC/DCC - Low
Address:Base + 2
Access:Read or Write
Register:DBC/DCC - High
Address:Base + 3
Access:Read or Write
Figure 9–4. DMA Base and Current Count Registers.
9-10
DMA Controller (V40)
DMA Base Address/Current Address (DBA/DCA)
Three DBA/DCA registers specify the 20-bit address. The format of
these registers is shown in Figure 9-5. The lower 16 bits of the
address can be accessed with byte or word instructions. The upper
four bits must be accessed with byte instructions. As is the case with
the DBC/DCC registers, the BASE bit of the DCH register defines the
operation of the DBA/DCA registers. A logical 0 in the BASE bit
specifies that values written to the Address registers are programmed
to both base and current values and data read will be current values. If
the BASE bit is a logical 1, the values written to the Address registers
are programmed into the base value only. The base value is read from
the Count registers if the BASE bit is set to a logical 1.
7
6
5
4
3
2
1
0
A7
A6
A5
A4
A3
A2
A1
A0
7
6
5
4
3
2
1
0
A9
A8
1
0
A15 A14 A13 A12 A11 A10
7
6
5
4
—
—
—
—
3
2
A19 A18 A17 A16
Register:DBA/DCA - Low
Address:Base + 4
Access:Read or Write
Register:DBA/DCA - Middle
Address:Base + 5
Access:Read or Write
Register:DBA/DCA - High
Address:Base + 6
Access:Read or Write
Figure 9–5. DMA Base and Current Address Registers.
9-11
DMA Controller (V40)
DMA Device Control (DDC)
Two DDC registers select various DCU operating modes. The format
for these registers is shown in Figure 9-6. These registers can be
accessed with byte or word operations. The DDMA bit can be set to a
logical 1 to prevent the DCU from requesting bus access. This should
be done when programming any of the DCU registers to prevent
incorrect DMA operation,
The WEV bit enables or disables wait states to be inserted by the V40
WCU during the verify operation. Programming WEV with a logical 0 disables wait state insertion and programming a logical 1
enables it.
7
6
5
4
3
2
1
0
—
—
0
—
— DDMA —
—
Register:DDC Low
Address:Base + 8
Access:Read or Write
Disable DMA Operation
0 Enable
1 Disable
7
6
5
4
3
2
1
0
—
—
—
—
—
— WEV —
Register:DDC High
Address:Base + 9
Access:Read or Write
Wait Enable During Verify
0 Disable
1 Enable
Figure 9–6. DMA Device Control Registers.
9-12
DMA Controller (V40)
DMA Mode (DMD)
Figure 9-7 shows the format of the DMD register. The DMD register
can be accessed with byte or word instructions. The TDIR field
defines the mode of data transfer. A logical 0 in both bits selects the
verify operation. A logical 1 in bit 2 and a logical 0 in bit 3 selects
I/O-to-memory transfers. For memory-to-I/O transfers, bit 2 must be
programmed with a logical 0 and bit 3 with a logical 1.
7
6
TMODE
5
4
ADIR AUTI
3
2
TDIR
1
0
—
—
Register:DMD
Address:Base + A
Access:Read or Write
Transfer Direction
00 Verify
01 I/O-to-memory
10 Memory-to-I/O
11 Not allowed
Autoinitialize
0 Disable
1 Enable
Address Direction
0 Increment
1 Decrement
Transfer Mode
00 Demand
01 Single
10 Block
11 Not allowed
Figure 9–7. DMA Mode Register.
9-13
DMA Controller (V40)
Autoinitialize is a feature that automatically reloads the DCU Current
Address and Current Count registers from the Base Address and Base
Count registers, respectively. The reload is done when the Count
register reaches zero. The autoinitialize feature is disabled by
programming AUTI with a logical 0 and enabled with a logical 1.
The ADIR bit defines the operation of the DCU address adjuster. If
ADIR is programmed with a logical 0, the address adjuster increments
the memory address after each data transfer. If ADIR is programmed
with a logical 1, the address is decremented. TMODE defines the
transfer mode to be demand, single, or block. These operating modes
are explained later in this chapter.
9-14
DMA Controller (V40)
DMA Status (DST)
The Status register includes information about the currently
programmed state of the DMA channel. The format for DST is shown
in Figure 9-8. DST is accessed with the byte read instruction. The
TC0 bit indicates when the count register has reached zero and the
DMA transfer is completed. A logical 0 in TC0 means that the
operation has not been terminated and a logical 1 means that it has.
The RQ0 bit defines the state of the DMA request input. A logical 0
indicates no request active and a logical 1 indicates a request is
pending.
7
6
5
4
3
2
1
0
—
—
—
RQ0
—
—
—
TC0
Register:DST
Address:Base +B
Access:Read Only
Terminal Count
0 Not ended (for each read)
1 END or terminal count
DMA Request
0 No DMA request active
1 DMA request active
Figure 9–8. DMA Status Register.
9-15
DMA Controller (V40)
DMA Mask (DMK)
The DMK register, shown in Figure 9-9, is used to mask DMA
requests made by the DMA channel. The register is accessed with
either byte write or read instructions. To mask a DMA channel, the
respective bit must be programmed with a logical 1. A logical 0
enables the DMA channel to make requests.
7
6
5
4
3
2
1
0
—
—
—
—
1
1
1
M0
Register:DMK
Address:Base + F
Access:Read or Write
DMARQ Mask
0 Not masked
1 Masked
Figure 9–9. DMA Mask Register.
9-16
DMA Controller (V40)
OPERATION
Reset
The DCU registers are initialized after power-on or after a pushbutton
reset. Table 9-2 shows the initialized state.
Table 9-2
DCU Register Default State.
Default Bit Value [1]
Register
7
6
5
4
3
2
1
0
DCH
DMD
DDC (low)
DDC (high)
DST
DMK
0
-
0
-
0
0
-
0
0
0
-
0
0
0
1
0
0
0
0
1
0
0
0
1
1
0
0
0
1
[1]Bit positions marked with a dash (-) can default to 1 or 0.
Single Mode Transfers
In single mode transfers, the DCU releases control of the bus after
each data transfer. The DCU then enters a slave mode, permitting
lower priority bus masters to gain access to the bus resources.
Demand Mode Transfers
With the DCU programmed for demand mode, the DMA channel is
serviced until the DMA request for that channel is removed. The
DCU then releases control of the bus and enters a slave mode,
permitting lower priority bus masters to gain access to the bus
resources.
9-17
DMA Controller (V40)
Block Mode Transfers
In block transfer mode, the DCU continues servicing the DMA
channel until the count register is decremented to zero. At this time
the DCU releases control of the buses and enters a slave mode of
operation, permitting lower priority bus masters to gain access to the
bus resources.
Autoinitialization
Autoinitialization is useful when doing repetitive DMA transfers
using the same amount of data and the same memory locations. The
DMA channel can be programmed for autoinitialization with the
DMD register. If autoinitialize is selected, the DCU automatically
transfers the previously programmed base address and base count to
the current address and current count, respectively.
Programming
The DCU is enabled and mapped into an I/O address range using the
V40 configuration register. DMA operation must be disabled with the
DDMA bit of the DDC register during DCU programming. Erroneous
operation may otherwise result. For example, if the two-byte address
register is being programmed by the CPU and a DMA request occurs,
it is possible that only one of the bytes may be updated before the
DMA channeled is serviced. The address would then be incorrect, and
the DMA operation invalid.
9-18
Chapter 10
SERIAL COMMUNICATIONS (V40)
Contents
Page
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-2
ZT 8832 SPECIFICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-2
FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3
Read/Write Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4
Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4
Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4
Interrupt Generation Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4
PROGRAMMABLE REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5
Serial Status Register (SST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-6
Serial Command Register (SCM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-8
Serial Mode Register (SMD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-9
Serial Interrupt Mask Register (SIMK) . . . . . . . . . . . . . . . . . . . . . . . 10-10
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-11
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-11
Serial Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-12
Baud Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-13
Interrupt and Polled Communication . . . . . . . . . . . . . . . . . . . . . . . . . 10-15
Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-16
10-1
Serial Communications (V40)
OVERVIEW
This chapter describes the Serial Control Unit (SCU) and provides
register descriptions and baud rate information.
The SCU is a single serial channel that performs asynchronous serial
communication between the V40 and a serial device external to the
ZT 8832.
The major features of the SCU are listed below.
•
Full-duplex asynchronous operation
•
Clock divisor of 16 or 64
•
Baud rates to 38.4 Kbaud
•
Programmable character format
•
Automatic break detect and handling
•
Parity, overrun, and framing detection
•
Interrupt and polled operation
ZT 8832 SPECIFICS
The SCU is implemented as a 3-wire RS-232-C serial port, including
Transmit Data (TxD), Receive Data (RxD), and Ground (GND).
These signals are available at connector J5; pin assignments are
shown on page B-16.
10-2
Serial Communications (V40)
FUNCTIONAL DESCRIPTION
The SCU is similar to the 8251 Serial Control Unit for asynchronous
operation. The SCU does not support synchronous communication
protocols. Figure 10-1 shows a functional block diagram of the SCU.
A description of each functional block follows.
RESET
CLOCK
IORD
SST
(Status Register)
IOWR
EN
RTCLK
SRB
(Receive
Data Buffer)
(8)
STB
(Transmit
Data Buffer)
(8)
SMD
(Mode Register)
SIMK
(Interrupt
Mask Register)
A2
A1
SCM
(Command
Register)
Receiver
RxD
TxD
SCU Status and Control Bus
Internal Data Bus (Higher or Lower 8 Bits)
Read/Write
Control
Transmitter
Interrupt
Generation Logic
SINT (to ICU)
Figure 10–1. SCU Block Diagram.
10-3
Serial Communications (V40)
Read/Write Control
The Read/Write Control block acts as an interface between the
internal registers of the SCU and the CPU. The control signals input
to the Read/Write Control logic, select internal registers, and control
the transfer of information between the CPU and the SCU.
Receiver
The Receiver block converts serial data input on the RxD signal to a
parallel format with the start, stop, and parity bits removed. The
parallel data is placed in the Serial Receive Buffer, and the Receive
Buffer Ready bit in the Serial Status register is set to a logical 1.
Activating the Receive Buffer Ready bit generates an interrupt if the
interrupts are not masked. The Receiver is also responsible for testing
data parity and monitoring for a Receive Break.
Transmitter
The Transmitter block converts the contents of the Serial Transmit
Buffer from a parallel format into a serial string. Start, stop, and
parity bits are added, as specified by the programmer in the Serial
Mode register. Next, the modified serial string is transmitted out of
the TxD signal at a rate equal to 1/16 or 1/64 that of the
Receiver/Transmitter Clock, also defined in the Serial Mode register.
The Transmit Buffer Ready bit in the Serial Status register is set to
alert the application program that it is clear to send the next character.
Activating the Transmit Buffer Ready bit generates an interrupt if the
interrupts are not masked by the Serial Interrupt Mask register.
Interrupt Generation Logic
The Interrupt Generation Logic block can interrupt the CPU when
data is received into the Serial Receive Buffer or transmitted from the
Serial Transmit Buffer. These interrupts are used to vector the
application program to service routines that read a character from the
Serial Receive Buffer and write a character to the Serial Transmit
Buffer, respectively.
10-4
Serial Communications (V40)
PROGRAMMABLE REGISTERS
Six registers are used for communication with the SCU. The Serial
Transmit Buffer (STB) and Serial Receive Buffer (SRB) store data to
be transferred to the serial link and from the serial link, respectively.
The Serial Command (SCM) and Serial Mode (SMD) registers define
the operating mode. The Serial Interrupt Mask (SIMK) register
controls the receive and transmit interrupts. The Serial Status (SST)
register provides information on the current state of the transmitter
and receiver.
The base I/O address of the SCU registers is defined by the OPHA
and SULA registers. OPHA is programmed with the high byte and
SULA with the low byte of the 16-bit address; see page 6-5 for
details. The address of each register, relative to the base address, is
shown in Table 10-1.
Table 10-1
SCU Register Addressing.
Address
Register
Operation
Page
Number
Base + 0
Base + 0
Base + 1
Base + 1
Base + 2
Base + 3
Receive Buffer
Transmit Buffer
Status Register
Command Register
Mode Register
Interrupt Mask Register
Read
Write
Read
Write
Write
Read/Write
10-5
10-5
10-6
10-8
10-9
10-10
10-5
Serial Communications (V40)
Serial Status Register (SST)
Figure 10-2 shows the architecture of the SST register, which can be
read at any time.
7
1
6
5
4
3
BKD FE OVE PE
2
1
1
0
RBR TBR
Register:Serial Status (SST)
Address:Base + 1
Access:Read
Transmit Buffer Ready
0 STB full
1 STB empty
Receive Buffer Ready
0 SRB empty
1 SRB full
Parity Error
0 No error
1 Error occurred
Overrun Error
0 No error
1 Error occurred
Framing Error
0 No error
1 Error occurred
Break
0 Normal reception
1 Break detected
Figure 10–2. Serial Status Register.
The first two bits define the state of the STB (Serial Transmit Buffer)
and SRB (Serial Receive Buffer). TBRDY (Transmit Buffer Ready)
is set to a logical 1 when a character is transferred out of the STB.
Application software uses TBRDY to determine when it is clear to
send a new character to the STB. TBRDY is automatically reset when
a new character is transferred into the STB. The RBRDY (Receive
10-6
Serial Communications (V40)
Buffer Ready) bit is set to a logical 1 when a character is transferred
into the SRB. Application software uses RBRDY to determine if a
character is available. RBRDY is automatically reset when the
character is read from the SRB.
The PE (Parity Error), OVE (Overrun Error) and FE (Framing Error)
bits flag data communication errors. The PE bit is set to a logical 1 if
a character is received into the SRB with a mismatch between the
parity bit and the character itself. The test for parity can be enabled
and disabled using the Serial Mode register.
An overrun error occurs when a character is written to the STB before
the character currently in the buffer is transmitted. The overrun error
is flagged with a logical 1 in the OVE bit. Avoid overrun errors by
having the application software test the TBRDY bit before writing the
character. A second type of overrun occurs if a character is received
into the SRB before the character currently in the buffer is read by the
application program. This type of overrun is avoided if the application
software reads the character before another is received. This can be
done on a polled basis by testing the RBRDY flag at a frequency
greater than the rate in which the characters are transferred or by
using the SCU interrupt capabilities to signal the presence of a
character to be read.
The FE bit is set to a logical 1 to flag a third type of error called a
framing error. A framing error signals a missing stop bit. This
happens when a break sequence is detected or when the programmed
baud rate is not the same as device on the other end of the serial link.
Once set to flag an error, the PE, OVE and FE bits remain set until a
logical 1 is written to the Error Clear bit of the Serial Command
register.
The BKD bit is set to a logical 1 when a break sequence is detected.
A break sequence is detected when a complete character, from the
start bit through the stop bit, is received with RxD in a low state. The
BRK bit is reset when RxD returns to a high state or the SCU is reset.
10-7
Serial Communications (V40)
Serial Command Register (SCM)
Figure 10-3 illustrates the SCM register bit map. The SCU is configured with the SCM and the SMD registers. The SCM register
includes the functions that are most likely to be modified during
operation. The SMD register will more than likely be programmed
just once for initialization.
7
6
5
—
—
—
4
3
2
ECL SBRK RE
1
0
—
TE
Register:Serial Command (SCM)
Address:Base + 1
Access:Write
Transmitter Enabled
0 Transmitter disabled
1 Transmitter enabled
Receiver Enabled
0 Receiver disabled
1 Receiver enabled
Send Break
0 Normal operation
1 TxD = 0 (break)
Error Clear
0 No operation
1 Error flag clear
Figure 10–3. Serial Command Register.
Bits 0 and 2 are the Transmitter and Receiver control bits. Setting TE
to a logical 1 enables the transmitter and a logical 0 disables it. If TE
is reset during transmission, the data in the Serial Transmit Buffer will
be sent before transmission stops and TxD goes to a high level.
Setting the RE bit to a logical 1 enables the receiver and resetting the
RE bit disables it.
A break sequence is transmitted if the SBRK bit is set to a logical 1.
This mode of operation is independent of the Receiver Enable bit.
The break sequence is transmitted until SBRK is reset.
The ECL bit is used to reset the parity, overflow, and framing error
bits of the Serial Status register. These bits are set to a logical 1 if
10-8
Serial Communications (V40)
error conditions occur and remain set until a logical 1 is written to the
ECL bit.
Serial Mode Register (SMD)
Figure 10-4 shows the format for the SMD register. This register
includes all the functions that are not likely to change after they have
been initialized. Bits 1 and 2 combine to define the clock divisor for
the baud rate. Programming the baud rate is defined in more detail on
page 10-13.
The character length is programmed with the CL field. If a character
length of seven is selected, the SCU transmits the lower seven bits of
the 8-bit character written by the CPU. Characters read by the CPU
will have a logical 0 in the most significant bit position.
7
6
STL
5
4
PS
3
2
CL
1
0
BF
Register:Serial Mode (SMD)
Address:Base + 2
Access:Write
Baud Rate Factor
00,01 Illegal
10 RTCLK frequency ÷ 16
11 RTCLK frequency ÷ 64
Character Length
00,01 Illegal
10 7-bit characters
11 8-bit characters
Parity Select
00,10 No Parity
01 Odd parity
11 Even parity
Stop Bit Length
00,10 Illegal
01 1 stop bit
11 2 stop bits
Figure 10–4. Serial Mode Register.
10-9
Serial Communications (V40)
Enabling even or odd parity is the function of the PS field. Parity is
disabled if a logical 0 is written to bit 4. If parity is disabled, the
parity bit will not be appended to the characters transmitted and the
characters received will not be tested. If bit 4 is a logical 1, parity is
enabled. Bit 5 selects between even or odd format. A character has
even parity if it includes an even number of bits set to a logical 1. A
character has odd parity if it includes an odd number of bits set to a
logical 1.
The number of stop bits appended to the character during transmission
or stripped off during reception is defined by the STL bit field. The
choice is between one or two stop bits.
Serial Interrupt Mask Register (SIMK)
The SCU is capable of interrupting the CPU when a character is
received into the Serial Receive Buffer or transmitted out of the Serial
Transmit Buffer. The SIMK register includes two programmable bits,
as illustrated in Figure 10-5, to enable the interrupts. Setting the RM
bit to a logical 1 prevents the SCU from generating an interrupt when
a character is received. A logical 0 in the RM bit enables the interrupt.
The TM bit provides the same control for transmitted characters.
7
6
5
4
3
2
—
—
—
—
—
—
1
0
TM RM
Register:Serial Interrupt Mask (SIMK)
Address:Base + 3
Access:Read/Write
Receiver Mask
0 Unmask
1 Mask
Transmitter Mask
0 Unmask
1 Mask
Figure 10–5. Serial Interrupt Mask Register.
10-10
Serial Communications (V40)
OPERATION
Reset
The SCU registers are automatically initialized to a default state when
power is applied to the ZT 8832, or during a reset. Table 10-2 shows
the default state for these registers.
Table 10-2
SCU Register Defaults.
Register
7
Default Bit Value [1]
6
5
4
3
2
SST
SCM
SMD
SIMK
1
0
-
0
1
-
0
0
0
-
0
0
0
-
0
0
1
-
1
0
0
-
1
0
0
1
1
0
0
1
1
[1] Bit positions marked with a dash (-) can default to 1 or 0.
10-11
Serial Communications (V40)
Serial Data Format
The SCU supports asynchronous communication. The asynchronous
data format is shown in Figure 10-6 to include start, stop, and optional
parity bits, as well as seven or eight data bits.
The state of the TxD line, when data is not being transmitted, is the
"mark" state. The start bit indicates the beginning of the serial data or
character bits. The parity bit is inserted for transmission and tested for
reception if parity is enabled in the SMD register. The stop bit flags
the end of the serial data. The number of stop bits is programmed into
the SMD register.
Also shown in Figure 10-6 is the format for a break sequence. The
detection of a break sequence is flagged in the Serial Status register.
The Serial Command register can be programmed to transmit the
break sequence.
Marking
Start
Bit
7or 8 Data Bits
Optional
Parity Bit
Asynchronous Data Format
Marking
Start
Bit
7 or 8 Data Bits
Optional 1 or 2
Stop
Parity
Bits
Bit
Break Sequence Format
Figure 10–6. SCU Serial Data Format.
10-12
1 or 2
Stop
Bits
Serial Communications (V40)
Baud Rate
The SCU baud rate is determined by the output of counter/timer 1.
Counter/timer 1 must be initialized for a specific mode of operation
and programmed with a count that defines the required baud rate. The
discussion below explains initialization and how to calculate the
count.
To use counter/timer 1 as a baud rate generator, the TCKS register ust
specify that counter/timer 1 has an internal clock with a divisor
determined by the formula shown below. The TCU Counter/Timer
Mode register must also be programmed to configure counter/timer 1
for binary operation as a square wave generator (Mode 3). Different
baud rates are obtained by programming counter/timer 1 with
different counts. The relationship between the baud rate and the count
is given below:
Count = V40 Clock / (Prescale x Baud Rate x Baud Factor)
This formula includes all the factors that determine the baud rate as a
function of the V40 clock. The best way to understand the formula is
to trace the clock signal from the V40 clock to the SCU. The V40
clock starts with a value of 8.0 x 106 Hz. This frequency is Prescaled
as defined by the PS bits in the TCKS V40 configuration register. At
this point the clock is input to the counter/timers. Counter/timer 1
further divides the signal by the programmed count before it is input
to the SCU. The last division is done internal to the SCU by the baud
factor programmed in the BF bits of the Serial Mode register.
As an example, assume the following parameters are specified:
V40 Clock = 8.0 x 106 Hz
Prescale = divide by two (TCKS PS bits = 00)
Baud Rate = 9600
Baud Factor = divide by 16 (SMD BF bits = 10)
10-13
Serial Communications (V40)
The calculation to determine the count value to be programmed into
counter/timer 1 is shown below to be 26. Note that the calculated
count and the programmed count differ by 0.16 percent. To guarantee
proper operation, the percent difference must never be greater than
four. Table 10-3 lists the count values to be programmed into
counter/timer 1 to generate the more common baud rates.
Count = 8 x 106 / (2 x 9600 x 16) = 26.04
Table 10-3
ZT 8832 Baud Rate Counts.
Count Dec/Hex [1]
Baud Rate
Baud Factor
Divided By:
16
110
150
300
600
1200
2400
4800
9600
19200
38400
2273/08E1
1667/0683
833/0341
417/01A1
208/00D0
104/0068
52/0034
26/001A
13/000D
[2]
64
568/0238
417/01A1
208/00D0
104/0068
52/0034
26/001A
13/000D
[2]
[2]
[2]
[1] The count values listed assume the PS bits of the TCKS V40 configuration
register are programmed with logical 0s.
[2] This combination exceeds the recommended 4% error allowance.
10-14
Serial Communications (V40)
If the counter/timers are driven with the external TCLK pin through
connector J3, instead of with the V40 clock, use the formula below
for calculating the value to be loaded into counter/timer 1. Note that
the frequency of the external clock signal is not dependent on the PS
bit of the TCKS register.
Count = External Clock / (Baud Rate x Baud Factor)
Interrupt and Polled Communication
Serial data can be transferred and received either by polling status bits
or with interrupts. In a polled mode, the application program monitors
the SST register Transmit Buffer Ready and Receive Buffer Ready
signals to determine when to transfer a character to the SCU or when
a character is available.
The SCU is capable of generating interrupts for applications that
cannot afford time spent polling for status. A transmit interrupt is
generated when the transmitter is enabled, the transmit interrupt is not
masked, and the Serial Transmit Buffer is empty. A receive interrupt
occurs when the receiver is enabled, the receive interrupt is not
masked, and a character is received by the Serial Receive Buffer.
10-15
Serial Communications (V40)
Programming
The SCU is enabled and mapped into an I/O address range using the
V40 Configuration register. The SCU includes four programmable
registers. The steps listed below outline the procedure for
programming the SCU for serial operation. The steps include
initializing counter/timer 1 to generate the baud rate.
1.
Program the TCKS V40 configuration register for counter/timer
1 to use the internal clock divided by two. Note that an external
clock or another divisor can be used, but the baud rate counts
shown in Table 10-3 must be adjusted.
2.
Program the TMD register of the TCU for binary count, square
wave generation (mode 3), low byte followed by high byte, and
selection of TCT1.
3.
Program the TCT1 Count register of the TCU with the selected
baud rate. Use a two-byte output operation — low byte followed
by high byte.
4.
Program the SMD register of the SCU with the selected baud
factor, character and stop bit length, and parity selection.
5.
Program the SCM and SIMK registers for the desired operation.
10-16
Chapter 11
SERIAL COMMUNICATIONS (82050)
Contents
Page
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-2
ZT 8832 SPECIFICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-3
FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4
Read/Write Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-5
Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-5
Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-5
Modem Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-6
Interrupt Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-6
PROGRAMMABLE REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-7
Transmit and Receive Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-8
Line Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-8
Line Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-11
Modem Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-13
Modem Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-15
Divisor Latch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-17
Interrupt Identify . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-18
Interrupt Enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-19
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-20
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-20
Serial Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-21
Baud Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-22
Interrupt and Polled Communication . . . . . . . . . . . . . . . . . . . . . . . . . . 11-23
RS-485 Serial Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-23
Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-24
11-1
Serial Communications (82050)
OVERVIEW
This chapter describes the Asynchronous Communication Controller
(ACC) and provides register descriptions and baud rate information.
The ACC is the Intel 82050 or equivalent. It is a single asynchronous
serial channel that performs serial communication between the
ZT 8832 and an external serial device. The major features of the ACC
are listed below.
•
Full-duplex asynchronous operation
•
Programmable baud rates up to 56 Kbaud
•
Programmable character format
•
Automatic break detect and handling
•
Parity, overrun, and framing detection
•
Interrupt and polled operation
•
Loopback diagnostics
•
Double buffering
11-2
Serial Communications (82050)
ZT 8832 SPECIFICS
The ACC serial port, available at connector J2, includes Transmit
Data (TxD), Receive Data (RxD), and support for a complete
selection of the following modem control functions:
•
Clear To Send (CTS)
•
Request To Send (RTS)
•
Data Terminal Ready (DTR)
•
Data Set Ready (DSR)
•
Ring Indicator (RI)
•
Data Carrier Detect (DCD)
The serial port is jumper configured to operate as either Data Communication Equipment (DCE) or Data Terminal Equipment (DTE)
with either RS-232 or RS-485 protocols. Pin assignments for
connector J2 are shown in Appendix B for both RS-232 and RS-485
operation.
The ACC supports interrupt driven communications. The interrupt
output of the ACC is connected to the IR4 interrupt input of the V40
interrupt controller.
When the ACC serial port is jumper configured to operate in RS-485
mode, the DTR bit of the ACC Modem Control register enables and
disables the transmit and request to send buffers. (See page 11-13.)
Regardless of whether the ACC is configured to operate in RS-232 or
RS-485 mode, the OUT2 bit of the Modem Control register enables
and disables the 24 bits of parallel I/O local to the ZT 8832.
11-3
Serial Communications (82050)
FUNCTIONAL DESCRIPTION
The ACC is functionally compatible with the industry standard
16450/8250A found in most Personal Computers. Figure 11-1
illustrates the major functional blocks of the ACC. A description of
each functional block follows.
Internal
Data Bus
D-D0
Data
Bus
Buffer
Receive
Buffer
Register
Receiver
RxD
Line
Control
Register
A0
A1
A2
EN
IORD
IOWR
RESET
Divisor
Latch (LSB)
Read/
Write
Control
Baud
Generator
Divisor
Latch (MSB)
Line
Status
Register
Transmitter
TxD
Transmit
Buffer
Register
Modem
Control
Register
Modem
Control
Modem
Status
Register
Interrupt
Enable
Register
OUT2/Parallel
Port Enable
Interrupt
Control
Interrupt
Identify
Register
Figure 11–1. ACC Block Diagram.
11-4
RTS
CTS
DTR /RS-485 CTRL
DSR
DCD
RI
IRQ
Serial Communications (82050)
Read/Write Control
The main function of the Read/Write Control block is to supervise the
interface between the ACC internal registers and the CPU. This
includes enabling one of the ACC programmable registers onto the
system data bus based on control signal inputs.
Receiver
The Receiver block converts serial data input on the RxD signal to a
parallel format with the start, stop, and parity bits removed. The
parallel data is placed in the Receive Buffer and the receiver Data
Ready bit in the Line Status register is set to a logical 1. Activating
the Data Ready bit generates an interrupt if the receive data interrupt
is not masked by the Interrupt Enable register. The Receiver also
monitors the incoming data for parity, overrun, and framing errors,
and reports any such errors to the Line Status register.
Transmitter
The Transmitter block converts the contents of the Transmit Buffer
from a parallel format into a serial string. Start, stop, and parity bits
are added, as specified by the programmer in the Line Control
register. The serial string is then transmitted out of the TxD signal and
the Transmitter Holding Register Empty bit is set to indicate that the
ACC is ready to accept a new character for transmission. Activating
the Transmitter Holding Register Empty bit will also generate an
interrupt if the transmit data interrupt is not masked by the Interrupt
Enable register.
11-5
Serial Communications (82050)
Modem Control
The Modem Control block includes the serial communication
handshake, RS-485 buffer control, and parallel port enable signals.
The serial handshake signals output by this control block are Request
to Send (RTS) and Data Terminal Ready (DTR). The DTR signal also
serves as an enable for the Transmit Data and Request To Send
drivers when the ACC is configured for RS-485 operation. Both the
RTS and DTR signals are programmable through the Modem Control
register. The serial handshake signals monitored by this control block
are Clear to Send (CTS), Data Set Ready (DSR), Data Carrier Detect
(DCD), and Ring Indicator (RI). These signals are monitored through
the Modem Status register. The remaining OUT2 signal is programmable through the Modem Control register to enable and disable
the 24 bits of parallel I/O on the ZT 8832.
Interrupt Control
The ACC includes a fully prioritized interrupt system to monitor and
report operating conditions such as receiver data available and
transmitter empty, and error conditions such as overrun, parity,
framing, and break. The Interrupt Control block monitors the interrupt
sources defined by the Interrupt Enable register and reports any active
interrupts through the Interrupt Identify register.
11-6
Serial Communications (82050)
PROGRAMMABLE REGISTERS
The remainder of the functional blocks illustrated in Figure 11-1 are
programmable registers. Table 11-1 shows the address of each of the
registers.
Table 11-5 on pages 11-25 and 11-26 summarizes the ACC register
set for programming reference.
Table 11-1
ACC Register Addressing.
Address
Register
Operation
Page #
03F8h (DL = 0)
Receive Buffer
Transmit Buffer
Divisor Latch LSB
Interrupt Enable
Divisor Latch MSB
Interrupt Identify
Line Control
Modem Control
Line Status
Modem Status
Reserved
Read
Write
Read/Write
Read/Write
Read/Write
Read
Read/Write
Read/Write
Read
Read/Write
--
11-8
11-8
11-17
11-19
11-17
11-18
11-8
11-13
11-11
11-15
--
(DL = 1)
03F9h (DL = 0)
(DL = 1)
03FAh (DL = X)
03FBh (DL = X)
03FCh (DL = X)
03FDh (DL = X)
03FEh (DL = X)
03FFh (DL = X)
11-7
Serial Communications (82050)
Transmit and Receive Buffer
The Transmit Buffer, Receive Buffer, and Interrupt Enable registers
share the same addresses as the Divisor Latch. Since the Divisor
Latch is programmed only once during system initialization, this
should cause no problems. During system initialization, the Divisor
Latch is selected by programming the Divisor Latch Access Bit of the
Line Control register. The Divisor Latch is then initialized to select
the appropriate baud rate, and the Divisor Latch Access Bit is
reprogrammed to enable the Transmit Buffer, Receive Buffer, and
Interrupt Enable register for serial communications.
Line Control
The main function of the Line Control register, shown in Figure 11-2,
is to define the format of the serial data.
The Word Length Select (WLS) field defines the character length, as
shown in Table 11-2.
Table 11-2
Serial Character Length.
11-8
Bit 1
Bit 0
Character Length
0
0
1
1
0
1
0
1
5 bits
6 bits
7 bits
8 bits
Serial Communications (82050)
7
6
DLAB SB
5
SP
4
3
2
EPS PEN STB
1
0
WLS
Register:Line Control
Address:03FBh
Access:Read/Write
Word Length Select
00 5 bits
01 6 bits
10 7 bits
11 8 bits
Stop Bits
0 1 stop bit
1 2 stop bits
(1-1/2 if WLS = 00)
Parity Enable
0 No parity
1 Parity
Even Parity Select
0 Odd Parity
1 Even Parity
Stick Parity
0 Disabled
1 Enabled
Set Break
0 Disabled
1 Enabled
Divisor Latch Access
0 Disabled
1 Enabled
Figure 11–2. Line Control Register.
11-9
Serial Communications (82050)
The STB bit selects the number of stop bits added to each character
transmitted and removed from each character received. Programming
STB with a logical 0 selects one stop bit; a logical 1 selects two stop
bits. The exception to this is when the character length is defined as
five. In this case, a logical 1 selects one and a half stop bits.
The parity options are programmed through the PEN, EPS, and SP
bits. PEN (bit 3) enables and disables parity. A logical 0 in PEN
disables parity and a logical 1 enables parity. With parity enabled, the
ACC adjusts the parity bit of transmitted data to produce an even or
an odd number of 1s when added to the character bits. With parity
enabled, the ACC also tests the parity of the received data.
The EPS bit selects even or odd parity. Even parity means that there is
an even number of 1s in the character data, including the parity bit.
Odd parity means that there is an odd number of 1s in the character
data, including the parity bit. Odd parity is selected by programming
bit 4 with a logical 0, and even parity is selected by programming
bit 4 with a logical 1.
Bit 5 (SP) is the stick parity bit. With bits 3 and 5 a logical 1, the
parity bit is transmitted and received in the state opposite that of bit 4.
The SB bit position enables and disables break control. A logical 0
disables break and a logical 1 enables it. Enabling break forces the
TxD output to the marking (negative) state.
The DLAB bit controls access to the ACC divisor latch. Programming bit 7 with a logical 1 selects the Divisor Latch; a logical 0
selects the Transmit Buffer, Receive Buffer, and Interrupt Enable
register.
11-10
Serial Communications (82050)
Line Status
The Line Status register, shown in Figure 11-3, provides information
to the CPU concerning the data transfer. Reading the Line Status
register clears bits 1 through 4 (OE, PE, FE, and BI).
7
0
6
5
4
TEMT THRE BI
3
2
1
0
FE
PE
OE
DR
Register:Line Status
Address:03FDh
Access:Read
Data Ready
0 No character available
1 Character available
Overrun Error
0 No error
1 Error
Parity Error
0 No error
1 Error
Framing Error
0 No error
1 Error
Break Interrupt
0 No break
1 Break
Transmitter Holding Register
0 Full
1 Empty
Transmitter Empty
0 Full
1 Empty
Figure 11–3. Line Status Register.
11-11
Serial Communications (82050)
The DR bit indicates the state of the ACC Receive Buffer. A logical 1
in the DR bit signals the availability of a character in the Receive
Buffer. The DR bit is automatically reset to a logical 0 when the
Receive Buffer is read.
The OE, PE, and FE bits are transmission error indicators. An
overrun error is indicated by a logical 1 in the OE bit, a parity error is
indicated by a logical 1 in the PE bit, and a framing error is indicated
by a logical 1 in the FE bit. In all cases, the error indicator is reset
when the Line Status register is read. An overrun error is generated
when a character is written into the Receive Buffer before the
previous character is read by the CPU. A parity error is generated
when the received character does not have the correct even or odd
parity. A framing error indicates that the received character does not
have a valid stop bit. Any of these error bits are capable of generating
an interrupt if enabled through the Interrupt Enable register.
The BI bit is set to a logical 1 when the RxD signal is held in the
marking (negative) state for longer than a single character transmission (including start, data, parity, and stop bits). Bit four is reset to
a logical 0 when the Line Status register is read. This bit is capable of
generating an interrupt if enabled through the Interrupt Enable
register.
The THRE and TEMT bits provide Transmitter status. A logical 1 in
the THRE bit signals that the Transmit Buffer is empty and ready to
receive a new character for transmission. This bit is capable of
generating an interrupt if enabled through the Interrupt Enable
register. TEMT is similar to bit 5 except that bit 6 is not set to a
logical 1 until both the Transmit Buffer and Transmit Shift register are
empty. Both THRE and TEMT bits are automatically reset to a
logical 0 with the loading of the next character to be transmitted.
Bit 7 is permanently set to logical 0.
11-12
Serial Communications (82050)
Modem Control
The Modem Control register, shown in Figure 11-4, includes the
serial handshake, RS-485 driver enable, and parallel port enable
signals.
7
6
5
0
0
0
4
3
LOOP OUT2
2
0
1
0
RTS DTR
Register:Modem Control
Address:03FCh
Access:Read/Write
Data Terminal Ready
0 DTR = mark
1 DTR = space
Request To Send
0 RTS = space
1 RTS = mark
Output 2
0 Parallel ports disabled
1 Parallel ports enabled
Loopback Diagnostics
0 Disabled
1 Enabled
Figure 11–4. Modem Control Register.
The DTR bit (bit 0) defines the state of the Data Terminal Ready
(DTR) signal. Programming the DTR bit with a logical 0 forces DTR
to a marking (negative) state, and programming the DTR bit with a
logical 1 forces DTR to a spacing (positive) state.
The DTR signal can be jumpered to enable and disable the RS-485
transmit data and request to send drivers if the ACC serial port is
configured for RS-485 operation. In this configuration, programming
the DTR bit with a logical 0 disables the drivers, and programming
the DTR bit with a logical 1 enables the drivers. The power-on state
of DTR disables the drivers.
11-13
Serial Communications (82050)
The RTS bit (bit 1) defines the state of the Request To Send (RTS)
signal. Programming the RTS bit with a logical 0 forces RTS to a
marking (negative) state, and programming the RTS bit with a
logical 1 forces RTS to a spacing (positive) state.
Bit 2 is permanently set to logical 0.
The OUT2 bit (bit 3) defines the state of the Output 2 (OUT2) signal.
The OUT2 signal is connected to the output control of the three
parallel ports available at connector J1. Programming OUT2 with a
logical 0 disables the parallel ports, and programming OUT2 with a
logical 1 enables the parallel ports. The power-on state of OUT2
disables the parallel ports.
The LOOP bit (bit 4) selects the internal loopback operation of the
ACC. Programming LOOP with a logical 0 disables loopback, and
programming LOOP with a logical 1 enables loopback. With loopback enabled, the following takes place:
–
The RxD input is ignored.
–
The TxD output is externally set to the marking (logical 1) state
and internally connected to RxD.
–
The modem control inputs (CTS, DSR, DCD, and RI) are
ignored.
–
The modem control outputs (DTR, RTS, and OUT2) are
externally forced to a logical 1 and internally connected to the
modem control inputs.
–
The receiver and transmitter interrupts are fully functional.
During loopback, the data transmitted is immediately received.
Bits 5-7 are permanently set to logical 0.
11-14
Serial Communications (82050)
Modem Status
Figure 11-5 shows the format of the Modem Status register. All eight
bits of this register are used to indicate the status of the serial data
transfer.
7
6
DCD RI
5
4
3
2
1
0
DSR CTS DDCD TERI DDSR DCTS
Register:ModemStatus
Address:03FEh
Access:Read/Write
Delta Clear To Send
0 CTS has not changed
1 CTS has changed
Delta Data Set Ready
0 DSR has not changed
1 DSR has changed
Trailing Edge Ring Indicator
0 No trailing edge received
1 Trailing edge received
Delta Data Carrier Detect
0 DCD has not changed
1 DCD has changed
Clear To Send
0 Space
1 Mark
Data Set Ready
0 Space
1 Mark
Ring Indicator
0 Space
1 Mark
Data Carriage Detect
0 Space
1 Mark
Figure 11–5. Modem Status Register.
11-15
Serial Communications (82050)
The DCTS, DDSR, and DDCD bits (bits 0, 1, and 3) are set to a
logical 1 to indicate that the CTS, DSR, and DCD bits have changed
state since the last time the Modem Status register was read.
The TERI bit (bit 2) signals the trailing edge detection of the Ring
Indicator (RI). The TERI bit is a logical 1 if the RI input changed
from a spacing (positive) state to a marking (negative) state since the
last time the Modem Status register was read.
The CTS bit (bit 4) reflects the state of the Clear To Send (CTS)
signal. If CTS is in the marking state, the CTS bit is a logical 0. If
CTS is in the spacing state, the CTS bit is a logical 1. During
loopback mode, the CTS bit is internally connected to RTS.
The DSR bit (bit 5) reflects the state of the Data Set Ready (DSR)
signal. If DSR is in the marking state, the DSR bit is a logical 0. If
DSR is in the spacing state, the DSR bit is a logical 1. During
loopback mode, the DSR bit is internally connected to DTR.
The RI bit (bit 6) reflects the state of the Ring Indicator (RI) signal. If
RI is in the marking state, the RI bit is a logical 0. If RI is in the
spacing state, the RI bit is a logical 1.
The DCD bit (bit 7) reflects the state of the Data Carrier Detect
(DCD) signal. If DCD is in the marking state, the DCD bit is a logical
0. If DCD is in the spacing state, the DCD bit is a logical 1.
11-16
Serial Communications (82050)
Divisor Latch
The ACC baud rate is selected by programming the least significant
byte (LSB) and most significant byte (MSB) of the Divisor Latch
shown in Figure 11-6. The Divisor Latch is programmed with an
integer value that divides the ACC oscillator reference frequency of
18.432 MHz into a value of 16 times the baud rate for both transmission and reception of serial data. The most common baud rate
divisors are shown in Table 11-4 on page 11-22.
15
14
13
12
11
10
D15 D14 D13 D12 D11 D10
MSB
9
8
7
6
5
4
3
2
1
0
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Divisor
Latch
(03F8/F9h,DL=1)
LSB
Figure 11–6. Divisor Latch.
11-17
Serial Communications (82050)
Interrupt Identify
The ACC includes 10 sources of interrupts prioritized into four
categories. The Interrupt Identify register flags whether or not the
ACC has an interrupt pending and, if so, from which of the four
categories it originated. Figure 11-7 below shows the format for the
Interrupt Identify register.
The IP bit indicates whether an interrupt is pending. A logical 0 in IP
signals an active interrupt, and a logical 1 in IP signals no active
interrupt. The interrupt sources are prioritized into the following four
categories: receiver status, receiver data, transmitter data, and modem
status, in that order. The interrupt ID field, bits 1 and 2, identifies the
interrupt category if there is an active interrupt.
7
6
5
4
3
RSV RSV RSV RSV RSV
2
1
IID
0
IPN
Register:Interrupt Identify
Address:03FAh
Access:Read
Interrupt Pending
0 Active interrupt
1 No active interrupt
Interrupt ID
00 ?
01 ?
10 ?
11 ?
Reserved
Reserved
Reserved
Reserved
Reserved
Figure 11–7. Interrupt Identify Register.
11-18
Serial Communications (82050)
Interrupt Enable
The Interrupt Enable register, shown in Figure 11-8, defines which of
the four categories of interrupts are enabled and which are not. The
Interrupt Enable register includes one bit for each of the four
categories of interrupts. Setting bits 0 through 3 all to a logical 0
prevents the ACC from generating an interrupt of any kind and
inhibits the Interrupt Identify register.
7
6
5
4
0
0
0
0
3
2
1
0
MSI RSI TBI RBI
Register:Interrupt Enable
Address:03F9h, DL=0
Access:Read/Write
Receive Buffer Interrupt
0 Disable
1 Enable
Transmit Buffer Interrupt
0 Disable
1 Enable
Receive Status Interrupt
0 Disable
1 Enable
Modem Status Interrupt
0 Disable
1 Enable
Figure 11–8. Interrupt Enable Register.
11-19
Serial Communications (82050)
OPERATION
Reset
The ACC registers are automatically initialized to a default state after
reset. Table 11-3 shows the default state for these registers.
Table 11-3
ACC Register Defaults.
Default Bit Value [1]
Register
7
6
5
4
3
2
1
0
Transmit Buffer
Receive Buffer
Line Control
Line Status
Modem Control
Modem Status
Divisor Latch (LSB)
Divisor Latch (MSB)
Interrupt Identify
Interrupt Enable
0
0
0
0
0
0
1
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
[1] Bit positions marked with a dash (-) can default to 1 or 0.
11-20
Serial Communications (82050)
Serial Data Format
The ACC supports asynchronous data transfers. The format for the
asynchronous data includes start, stop, and optional parity bits as well
as five, six, seven, or eight data bits. This is illustrated in Figure 11-9.
Marking
Start
Bit
7 or 8 Data Bits
Optional
Parity Bit
Asynchronous Data Format
Marking
Start
Bit
7 or 8 Data Bits
1 or 2
Stop
Bits
Optional 1 or 2
Stop
Parity
Bits
Bit
Break Sequence Format
Figure 11–9. ACC Serial Data Format.
The TxD signal is in the "mark" state when data is not being
transmitted. The start bit indicates the beginning of the serial data or
character bits. The parity bit is optionally inserted during transmission
and monitored during reception to test data integrity. The stop bit
flags the end of the serial data.
The format for the break sequence is also shown in Figure 11-9. The
transmission of the break sequence is programmed in the Line Control
register, and the reception of the break sequence is flagged in the Line
Status register.
11-21
Serial Communications (82050)
Baud Rate
The ACC includes an internal baud rate generator to divide the
18.432 MHz reference frequency down to a value equal to 16 times
the baud rate. The divisor for the reference frequency is a 16-bit
integer programmed into the LSB and MSB of the Divisor Latch. The
relationship between the baud rate and the count is as follows:
6
Divisor = 18.432 x 10 /(160 x Baud Rate)
Table 11-4 lists the divisor to be used for the more popular baud rates.
It also shows the percent error, which is based on the difference
between the exact divisor for a specified baud rate and the divisor
obtainable with a 16-bit integer format. To guarantee proper
operation, the percent error should never be greater than four.
Table 11-4
ACC Baud Rate Divisors.
11-22
Baud Rate
Divisor
(dec/hex)
Percent Error
50
75
150
300
600
1200
1800
2000
2400
3600
4800
7200
9600
19200
38400
56000
2304/1440
1536/0960
768/0480
384/0240
192/0120
96/0060
64/0040
58/003A
48/0030
32/0020
24/0018
16/0010
12/000C
6/0006
3/0003
2/0002
0
0
0
0
0
0
0
0.69
0
0
0
0
0
0
0
2.86
Serial Communications (82050)
Interrupt and Polled Communication
Serial data can be transferred and received either by polling status bits
or with interrupts. In a polled mode, the application program monitors
the Line Status register Data Ready and Transmitter Holding Register
Empty bits to determine when to transfer a character to the ACC or
when a character is available.
The ACC is capable of generating interrupts for applications that
cannot afford time wasted in polling for a status change. If enabled in
the Interrupt Enable register, a Transmitter Holding Register Empty
interrupt is generated when the transmitter is free to receive a
character. Also, if enabled in the Interrupt Enable register, a Received
Data Available interrupt is generated when a character is received by
the ACC.
RS-485 Serial Communications
The ZT 8832 includes jumper selectable drivers and receivers for both
RS-232-C and RS-485 serial communication protocols. The two main
advantages of RS-485 over RS-232-C are an increased number of
drivers and receivers (32 of each, versus one of each for RS-232-C)
and increased transmission distance (4000 feet, as compared to 50 feet
for RS-232-C).
A terminated twisted pair should be used to protect the integrity of the
RS-485 signals. A typical twisted pair has a characteristic impedance
in the range of 100 to 130 Ω, adequate for data transfer rates up to 10
MHz. The RS-485 balanced inputs can be terminated by installing
resistors at locations R13 and R14. The surface mount resistors must
have a 1206 case size, a power rating of at least 0.125 W, and a
resistance value equal to the characteristic impedance of the twisted
pair.
11-23
Serial Communications (82050)
Appendix B includes the pin numbers and signal descriptions of the
RS-232-C and RS-485 signals available through connector J2. (See
page B-13.) When configured for RS-485, Data Terminal Equipment
(DTE) is selected by plugging in the serial cable with pin 1 of the
cable lined up with pin 1 of the connector. To select Data
Communication Equipment (DCE), the serial cable should be plugged
in with pin 1 of the cable lined up with pin 14 of the connector.
Programming
Table 11-5 on the following pages summarizes the ACC register set
for programming reference.
11-24
Serial Communications (82050)
Table 11-5
ACC Register Summary.
Register Address
0 DLAB = 0
0 DLAB = 0
1 DLAB = 0
2
3
Bit
Interrupt IdenNo. Receive Buffer Transmit Buffer Interrupt Enable tify Register Line Control
Register
(Read Only)
(Write Only)
Register
(Read Only)
RBR
THR
IER
IIR
LCR
0
Data Bit 0*
Data Bit 0
Enable Receive
Buffer Full
Interrupt (MSI)
"0" if
Interrupt
Pending
Word Length
Select Bit 0
(WLS0)
1
Data Bit 1
Data Bit 1
Enable Transmit
Buffer Empty
Interrupt (RSI)
Interupt ID
Bit (0)
Word Length
Select Bit 1
(WLS1)
2
Data Bit 2
Data Bit 2
Enable Receive
Status Interrupt
(TBI)
Interrupt ID Number of Stop
Bit (1)
Bits (STB)
3
Data Bit 3
Data Bit 3
Enable Modem
Status Interrupt
(RBI)
0
Parity Enable
(PEN)
4
Data Bit 4
Data Bit 4
0
0
Even Parity
Select (EPS)
5
Data Bit 5
Data Bit 5
0
0
Stick Parity
6
Data Bit 6
Data Bit 6
0
0
Set Break
7
Data Bit 7
Data Bit 7
0
0
Divisor Latch
Access Bit
(DLAB)
*Bit 0 is the least significant bit. It is the first bit serially transmitted or received.
11-25
Serial Communications (82050)
Table 11-5
ACC Register Summary (continued).
Register Address
4
5
6
0 DLAB = 1 1 DLAB = 1
Modem
Control
Register
Line Status
Register
Modem
Status
Register
Divisor
Divisor
Latch (LSB) Latch (MSB)
MCR
LSR
MSR
DLL
DLM
0
Data
Terminal
Ready
(DTR)
Data Ready
(DR)
Delta Clear
to Send
(DCTS)
D0
D8
1
Request to
Send
(RTS)
Overrun
Error (OE)
Delta Data
Set Ready
(DDSR)
D1
D9
2
0
Parity
Error (PE)
Trailing Edge
Ring
Indicator
(TERI)
D2
D10
3
Out 2
Framing
Error (FE)
Delta Data
Carrier
Detect
(DDCD)
D3
D11
4
Loop
Break
Interrupt
(BI)
Clear to
Send (CTS)
D4
D12
5
0
Transmit
Holding
Register
(THRE)
Data Set
Ready (DSR)
D5
D13
6
0
Transmit
Empty
(TEMT)
Ring
Indicator
(RI)
D6
D14
7
0
0
Data Carrier
Detect
(DCD)
D7
D15
Bit
No.
11-26
Chapter 12
PARALLEL I/O
Contents
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ZT 8832 SPECIFICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output Latch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PROGRAMMABLE REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Programming the Parallel Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Programming the Light Emitting Diode . . . . . . . . . . . . . . . . . . . . . . . .
Mixing I/O in a Single Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page
12-1
12-2
12-3
12-3
12-4
12-4
12-5
12-6
12-6
12-6
12-7
12-7
OVERVIEW
The three 8-bit parallel ports provide a total of 24 I/O signals. Each
I/O signal can be configured either as an input or as an output with
readback. The major features of the parallel I/O are listed below.
•
Stable outputs during power-up and reset
•
Data transfer rates up to 1 Mbyte/second
•
Each I/O signal programmable for input or output with readback
•
Direct connection to industry standard I/O module mounting
racks
12-1
Parallel I/O
ZT 8832 SPECIFICS
The three parallel ports are available at connector J1; see page B-11
for pin assignments. In addition to the 24 I/O signals, connector J1
also supports ground and fused +5 V for direct interface to industry
standard I/O module mounting racks, such as Ziatech’s ZT 2226 or
those manufactured by Opto 22. The 1 A fuse is available from
Littelfuse (part number 275-001).
The two most significant parallel port signals are connected to other
devices in addition to the J1 connector. The most significant parallel
port signal (I/O address 220h, bit 7) is connected to J1 and the
watchdog timer. It functions as a strobe signal used to prevent the
watchdog timer from timing out. This connection is jumper
selectable. The second most significant parallel port bit (I/O address
220h, bit 6) is connected to J1 and the Light Emitting Diode (LED)
located next to connector J3.
The use of the parallel port with the watchdog timer is discussed in
Chapter 13. The use of the parallel port to control the LED is
discussed at the end of this chapter.
12-2
Parallel I/O
FUNCTIONAL DESCRIPTION
A functional diagram of each of the 24 I/O signals is illustrated in
Figure 12-1. The diagram includes an Output Latch, an Output Buffer,
and an Input Buffer. These functional blocks are described below.
Output Latch
The Output Latch stores the data present on the internal data bus
during a write operation to the parallel port. The data is latched until
altered by another parallel port write or until power is turned off.
While the Output Latch is not initialized after power-up, the state of
the parallel I/O signal at connector J1 is a TTL high because the
Output Buffer is disabled and the passive termination is in effect.
82050 Serial Port OUT2 Bit
Passive Termination
Internal Data Bus
Output
Data Latch
Connector J1
Output
Buffer
Input
Buffer
Figure 12–1. Parallel Port Functional Diagram.
12-3
Parallel I/O
Output Buffer
The Output Buffer isolates the Output Latch from connector J1. The
Output Buffer is disabled and enabled with the 82050 Serial Port
OUT2 bit. The OUT2 connection ensures that the Output Buffer is
disabled during and after power-up to prevent the I/O signals at
connector J1 from glitching. The OUT2 signal also disables the
Output Buffer during and after a reset.
The Output Buffer is an inverting open collector device. The
inversion means that a logical 0 written to the parallel port appears as
a TTL high at the J1 connector and a logical 1 written to the parallel
port appears as a TTL low at the J1 connector. It is the open collector
feature that permits each parallel I/O signal to be configured as an
input. To use the parallel I/O signal as input, a logical 0 must first be
written to the Output Latch to open collect the Output Buffer and
prevent contention with the input signal.
Input Buffer
The Input Buffer is enabled during read operations to transfer the data
from connector J1 to the internal data bus. If the parallel port bit is
configured as output, the data read is the last data written to the
parallel port bit. If the parallel port is configured as input, the data
read is the data driven by an external device.
The Input Buffer is an inverting device. This means that data read
from the parallel port as a logical 0 is actually a TTL high at
connector J1, and data read from the parallel port as a logical 1 is a
TTL low at connector J1.
12-4
Parallel I/O
PROGRAMMABLE REGISTERS
The 24 parallel I/O signals are accessible through three programmable
registers. The address of each of the registers is shown in Table 12-1.
Table 12-1
Parallel I/O Register Addressing.
Address
(hex)
Register
Operation
0200h
0210h
0220h
Parallel Port 0
Parallel Port 1
Parallel Port 2
Read/Write
Read/Write
Read/Write
12-5
Parallel I/O
OPERATION
Reset
The parallel port outputs are disabled and passively pulled to a TTL
high after power up or reset.
Programming the Parallel Ports
The parallel ports are enabled by writing a logical 1 to the 82050
serial port OUT2 bit (I/O port address 3FCh, bit 3). This operation
immediately transfers the contents of the parallel ports to the J1
connector. The contents of the parallel ports are not defined after
power-up. Therefore, it is recommended that all 24 bits be initialized
with logical 0s before the parallel port outputs are enabled. This
initialization does the following:
•
Maintains the power-up and reset state of a TTL high at
connector J1.
•
Prevents contention with external devices driving the parallel
I/O signals.
•
Ensures that a jumper selected watchdog timer is not armed.
Once enabled, the parallel port bits are programmed with standard
input and output instructions. The parallel ports are inverting so that
data written to the parallel port appears in the opposite state at
connector J1 and data read from the parallel port reflects the inverted
state of the data at connector J1.
The V40 supports string I/O instructions for transferring data between
the parallel I/O and memory at rates of up to 1 Mbyte/second. The
high throughput of these instructions occurs because the memory
address is automatically incremented or decremented after each
transfer.
12-6
Parallel I/O
Programming the Light Emitting Diode
•
To control the LED, first enable the parallel port by
programming the OUT2 bit of the 82050 serial port (I/O port
address 3FCh, bit 3) with a logical 1.
•
To turn on the LED, write a logical 1 to the second most
significant parallel I/O bit (I/O port address 220h, bit 6).
•
To turn off the LED, write a logical 0 to the second most
significant parallel I/O bit (I/O port address 220h, bit 6).
Mixing I/O in a Single Port
Each I/O signal is programmable for input or output operation. If
inputs and outputs are mixed in a single port, you must take special
care to always write logical 0s to the bit locations configured as
outputs.
For example, assume that the lower four bits of a port are inputs and
the upper four bits of the same port are outputs. For a read-modifywrite cycle, you must read the port, modify the output bits as
necessary, set the lower four bits to 0, and write the port.
12-7
Chapter 13
WATCHDOG TIMER
Contents
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ZT 8832 SPECIFICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 1 Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 1 Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Multiple Stages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing Time Delays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page
13-2
13-2
13-3
13-3
13-4
13-4
13-4
13-5
13-5
13-6
13-7
13-8
13-1
Watchdog Timer
OVERVIEW
The primary function of the watchdog timer is to monitor ZT 8832
operation and to take corrective action if the ZT 8832 fails to function
as programmed. The watchdog timer includes two stages. The firststage timeout generates a non-maskable interrupt. The second-stage
timeout generates a local reset. The major features of the watchdog
timer are listed below.
•
Enabled and disabled through jumper selection
•
Armed and strobed through software control
•
Increased programming flexibility with two stages
ZT 8832 SPECIFICS
The watchdog timer must be jumper selected before it is operational.
If the watchdog timer is selected, the most significant bit of the
parallel ports becomes dedicated to the watchdog timer and cannot be
used for general purpose I/O.
13-2
Watchdog Timer
FUNCTIONAL DESCRIPTION
Figure 13-1 illustrates a functional diagram of the watchdog timer.
The diagram includes a timer and a delay for each stage. The
functional blocks are described below.
Stage 1 Timer
The first stage of the watchdog timer generates a non-maskable
interrupt to the local CPU if the watchdog timer is jumper selected
and armed and a strobe does not occur within the time period defined
by the Stage 1 Delay functional block.
Non-maskable Interrupt
Stage 1
Delay
Stage 2
Delay
Stage 1
Timer
Stage 2
Timer
Local Reset
Arm/Strobe
Figure 13–1. Watchdog Timer Functional Diagram.
13-3
Watchdog Timer
Stage 1 Delay
The stage 1 delay has a default range of 60 ms minimum and 100 ms
maximum. The minimum delay time means that the watchdog timer
must be strobed with a period of less than 60 ms to prevent stage 1
from generating a non-maskable interrupt. The maximum delay time
means that it could take up to 100 ms after the watchdog timer is
strobed before the non-maskable interrupt occurs.
Stage 2 Timer
The second stage of the watchdog timer generates a reset to the local
CPU if the watchdog timer is jumper selected and armed and a strobe
does not occur within the time period defined by the Stage 2 Delay
functional block.
Stage 2 Delay
The stage 2 delay has a default range of 250 ms minimum and
1000 ms maximum. The stage 1 delay time must be subtracted from
the stage 2 delay time to determine how long the non-maskable interrupt service routine must strobe the stage 2 timer to prevent a local
reset. For the default configuration, this time is 150 (250 - 100) ms
minimum and 940 (1000 - 60) ms maximum. The minimum delay
time means that the watchdog timer must be strobed sooner than
150 ms after the stage 1 timeout to prevent a local reset. The maximum delay time means that it could take up to 940 ms after the nonmaskable interrupt before the local reset occurs if the watchdog is not
strobed.
13-4
Watchdog Timer
OPERATION
In operation, the local CPU is programmed to strobe the watchdog
timer at a periodic rate less than the stage 1 time delay. If the local
CPU fails to operate as programmed, stage 1 of the watchdog timer
generates a non-maskable interrupt. The non-maskable interrupt service routine takes the necessary corrective action that includes
strobing the watchdog timer before the stage 2 time delay to prevent a
local reset. If the local reset is desired, the non-maskable interrupt
service routine simply does not strobe the watchdog timer.
Reset
The watchdog timer is disarmed during and after both a power-up and
reset condition.
Stage 2 of the watchdog timer generates a local reset if allowed to
time out. This reset period lasts for up to 1 second. Since the STD bus
CPU is unaffected by this reset, it might attempt an I/O or dual port
access to the ZT 8832. If this occurs, the operation of the STD bus
CPU is suspended until the reset period is over. This suspension will
cause problems in a system having critical interrupt latencies, DMA
latencies, asynchronous data transfers, or dynamic RAM that must be
refreshed by the STD bus CPU.
13-5
Watchdog Timer
Multiple Stages
Many watchdog timers are implemented with a single stage that
generates a reset if allowed to time out. The problem with this
implementation is that the CPU does not have advance warning of the
reset. Without advance warning, the CPU cannot take corrective
action that includes, as a minimum, setting a flag indicating that a
system failure has occurred.
Other watchdog timers are implemented with a single stage that
generates a non-maskable interrupt if allowed to time out. The
problem with this implementation is that the pointer to the nonmaskable interrupt service routine is generally stored in RAM that can
be overwritten by a CPU not operating as programmed.
The solution to these problems is to implement a two-stage watchdog
timer such as the one found on the ZT 8832. If the first stage times
out, a non-maskable interrupt is generated to invoke a service routine
that takes the necessary corrective action. If the second stage times
out, a local reset is generated to put the ZT 8832 in a known operating
state.
13-6
Watchdog Timer
Changing Time Delays
Table 13-1 shows the two possibilities for the stage delays. The
stage 1 delay is measured from the watchdog strobe to the nonmaskable interrupt. The stage 2 delay is measured from the watchdog
strobe to the local reset. The stage 2 - stage 1 delay is calculated as
the non-maskable interrupt to local reset delay.
The first entry in Table 13-1 shows the default stage delays. The
second entry shows an option. The stage 1 delay is implemented with
a discrete surface mount resistor and capacitor. This delay cannot be
changed. The stage 2 delay can be changed by using cuttable traces,
as described on page A-18.
Table 13-1
Watchdog Timer Stage Delays.
Stage 1
(ms)
Stage 2
(ms)
Stage 2-Stage 1
(ms)
Default
60 min
100 max
250 min
1000 max
150 min
940 max
Optional
60 min
100 max
500 min
2000 max
400 min
1940 max
13-7
Watchdog Timer
Programming
The watchdog timer is armed and strobed with the most significant
parallel I/O signal. The watchdog timer is armed with the following
programming sequence.
1.
Initialize the most significant bit of the parallel ports (I/O port
address 220h, bit 7) with a logical 0.
2.
Enable the parallel ports by writing a logical 1 to the 82050
OUT2 bit (I/O port address 3FCh, bit 3).
3.
Arm the watchdog timer by programming the most significant
bit of the parallel ports with a logical 1.
The watchdog timer is strobed with the following programming
sequence.
1.
Disarm the watchdog timer by writing a logical 0 to the most
significant bit of the parallel ports.
2.
Rearm the watchdog timer by writing a logical 1 to the most
significant bit of the parallel ports.
In addition to the watchdog timer non-maskable interrupt, the
ZT 8832 also supports 8087 Numeric Data Processor and STD bus
control port non-maskable interrupts. If more than one source of nonmaskable interrupt is used in an application, the non-maskable
interrupt service routine must be able to identify the source of the
interrupt.
The watchdog timer non-maskable interrupt request is also routed into
IRQ1 of the interrupt controller. This enables the non-maskable
interrupt service routine to read the interrupt controller to determine if
the watchdog timer has generated a non-maskable interrupt request.
13-8
Chapter 14
SBX EXPANSION MODULE
Contents
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ZT 8832 SPECIFICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page
14-2
14-3
14-4
14-5
14-1
SBX Expansion Module
OVERVIEW
The SBX expansion module provides a method for expanding the I/O
capabilities of the ZT 8832. The expansion module interface is
electrically, mechanically, and functionally compatible with the Intel
iSBX MULTIMODULE standard. This level of compatibility ensures
that expansion modules produced by other manufacturers will operate
with the ZT 8832. Some of the functions available on expansion
modules are:
•
Serial and parallel I/O
•
Stepper and servo motor controllers
•
Analog-to-digital and digital-to-analog converters
•
Disk and SCSI controllers
•
Modems
•
Video controllers
•
IEEE 488 controllers
•
Bar code readers
•
Prototyping boards for customized I/O designs
14-2
SBX Expansion Module
Features
The major features of the expansion module interface are listed below.
•
Standard interface for expanding I/O capabilities
•
Compatible to Intel iSBX MULTIMODULE specification
•
DMA support for high speed data transfers
•
Added address lines for custom designs
•
Optional V40 CPU clock for custom synchronous designs
•
Supports both single-wide and double-wide expansion modules
14-3
SBX Expansion Module
ZT 8832 SPECIFICS
The expansion module interface is supported through connector J4;
the pin assignments given on page B-15. The expansion module
supports Direct Memory Access (DMA) using the DMA controller
discussed in Chapter 9. The DMA controller transfers data between
the expansion module and either local or dual port RAM at rates of up
to 1 1/3 Mbytes per second. The DMA signals supported are DMA
Request (MDRQT) and DMA Acknowledge (MDACK*). The
Terminate DMA (TDMA) signal is not supported.
The expansion module standard defines three address lines and two
chip selects. This provides a total of 16 I/O port addresses. To
overcome this limitation, the ZT 8832 expansion module adds four
address lines. These address lines are connected in the default
configuration and can be removed using cuttable traces (see
page A-19 for details). Without these address lines, the chip select 0
signal (MCS0*) is valid over the I/O address range 2F8 through 2FFh,
and the chip select 1 signal (MCS1*) is valid over the I/O address
range 300 through 307h. As the added address lines are used, the chip
select 0 signal grows downward in I/O address space and the chip
select 1 signal grows upward. For example, if all seven address lines
are used, chip select 0 is mapped to I/O address 280 through 2FFh and
chip select 1 is mapped from I/O address 300 through 37Fh.
The expansion module supports two interrupt request signals for
interrupt driven communications. Interrupt Request 0 (MINTR0*) is
connected to IRQ2 of the interrupt controller, and Interrupt Request 1
(MINTR1*) is connected to IRQ3 of the interrupt controller. The
interrupt controller is explained in detail in Chapter 8.
The expansion Module Present (MPST*) signal is not supported.
14-4
SBX Expansion Module
INSTALLATION
The SBX expansion module is installed on the ZT 8832 as shown in
Figure 14-1. The module is mechanically secured to the ZT 8832 at
the J4 connector and with the threaded spacer shipped with the
expansion module.
Figure 14–1. SBX Expansion Module Installation.
14-5
Chapter 15
NUMERIC DATA PROCESSOR (8087)
Contents
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ZT 8832 SPECIFICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Coprocessor Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Error Handling and Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Further Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page
15-2
15-2
15-3
15-4
15-4
15-6
15-7
15-1
Numeric Data Processor (8087)
OVERVIEW
The V40 is a high performance microprocessor designed for a wide
variety of applications. The math capabilities of the V40 include
addition, subtraction, multiplication, and division of 8-bit and 16-bit
numbers. However, the STD bus is often used in numerically
intensive applications needing more powerful arithmetic operations
and data types than those provided by the V40. The addition of the
8087 Numeric Data Processor (NDP) will provide the following
benefits.
•
68 additional instructions for extended arithmetic, trigonometric,
exponential, and logarithmic functions
•
Seven added data types, including integers (16-, 32-, and 64-bit),
floating point (32-, 64-, and 80-bit), and BCD (18-digit)
•
A typical performance increase of 100 times over software math
routines
•
Compatibility with the IEEE 754 Floating Point standard
•
Optional automatic error handling
ZT 8832 SPECIFICS
The NDP provides an interrupt to signal exception errors. This
interrupt is optionally connected to a non-maskable interrupt request
through jumper selection. The numeric data processor includes a
status word that indicates whether or not an interrupt request is active.
15-2
Numeric Data Processor (8087)
INSTALLATION
INSTALL 8087
HERE
ZT 8832 ICP
The NDP is installed in an empty socket on the ZT 8832 as shown in
Figure 15-1. The 8087-1 (10 MHz) is required for proper operation.
Be sure power is not applied to the ZT 8832 during installation.
Figure 15–1. 8087 Numeric Data Processor Installation.
15-3
Numeric Data Processor (8087)
OPERATION
The following description is an overview of NDP operation. See the
reference section at the end of this chapter for sources with more
detailed explanations.
Coprocessor Interface
Instruction Level Support
The purpose of the NDP is to extend the math capabilities of the V40.
This includes instruction level support for high-precision integer and
floating point data types with operations such as add, subtract,
multiply, divide, square root, exponent, logarithmic, and trigonometric. For the programmer, the NDP adds 68 numerical instructions
and seven data types to the V40 instruction set. The instructions are
referred to as ESCAPE instructions because they include an ESCAPE
prefix. The ESCAPE prefix signals the V40 and the NDP that a
numeric instruction is to be executed.
The NDP maintains a copy of the V40 instruction queue. Instructions
fetched by the V40 are also monitored by the NDP. The NDP checks
the first byte of each instruction looking for an ESCAPE prefix. If the
first byte is not an ESCAPE prefix, the NDP ignores the instruction.
If the first byte of an instruction is an ESCAPE prefix, the NDP
decodes the numeric instruction in parallel with the V40.
An NDP numerical instruction has one of three options:
1.
No reference to memory
2.
Read operand from memory
3.
Write operand to memory
If no reference to memory is needed, the NDP executes the
instruction. If the instruction includes a reference to memory, the V40
executes a "dummy read" cycle, so called because the V40 ignores the
data read. Because the NDP does not include an address generator, it
must depend on the V40 to generate the operand starting address.
15-4
Numeric Data Processor (8087)
Read and Write Operations
If a read operation is required, the NDP latches the address and
operand as it appears. If the operand is more than one word long, the
NDP is granted access to the address, data, and control buses for
subsequent read operations. This means that although the NDP does
not have the capability of determining the operand starting address, it
can latch the starting address and increment it for subsequent
operations. If the instruction includes a write to memory operation,
the NDP latches the address and, like the V40, ignores the data during
the dummy read. The NDP is then granted control of the buses to
complete the write operation.
The NDP must get control of the V40 address, data, and control buses
to write numerical operands to memory or to read numerical operands
longer than one word from memory. A request/grant/release protocol
is then used between the V40 and the NDP to carry out this transfer of
control:
1.
The NDP generates a request to the V40 to gain control of the
bus resources.
2.
The V40 responds by releasing the bus and granting control to
the NDP.
3.
The NDP completes the memory operation and releases control
back to the V40.
This entire operation is transparent to the programmer since it is done
with hardware.
The V40 can continue to fetch and execute instructions while the
NDP is performing numerical computations. The V40 WAIT
instruction can be used to suspend V40 operation until the NDP has
completed the numerical computation.
15-5
Numeric Data Processor (8087)
Error Handling and Interrupts
A numeric error occurs if an operation is attempted with invalid
operands or if the result of a computation cannot be accurately
represented. Six defined error conditions can occur during the
execution of a numeric instruction:
•
Invalid operation
•
Overflow
•
Zero divisor
•
Underflow
•
Denormalized operand
•
Inexact result
The NDP can be programmed to interrupt the V40 during any or all of
these errors. For an interrupt to be recognized, the NDP must be
programmed to enable interrupts and remove the mask of the selected
error condition. If the NDP interrupts are disabled when an error
occurs, the V40 is not interrupted and NDP operation continues. If the
NDP interrupts are enabled and an error occurs that is masked, the
NDP will flag the error in a status register and automatically execute a
default handling procedure. If the NDP interrupts are enabled and an
error occurs that is not masked, an interrupt will be generated to the
V40. This interrupt must be supported with an interrupt service
routine in the application program.
15-6
Numeric Data Processor (8087)
Further Reference
–
Cooner, Jerome, "An Implementation Guide to a Proposed
Standard for Floating Point," Computer, Institute of Electrical
and Electronic Engineers, Jan. 1980.
–
Palmer, John, & Wymore, Charles, "Making Mainframe
Mathematics Accessible to MicroComputers," Electronics, 8
May 1982. (or AR-135 from Intel Corporation)
–
Rash, Bill, "Getting Started with the Numeric Data Processor,"
Intel Corporation.
–
"The NDP User’s Manual Numerics Supplement," Intel
Corporation.
–
"Microsystem Components Handbook," Volume I,
Corporation.
Intel
15-7
IV. APPENDICES
JUMPER CONFIGURATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1
CUSTOMER SUPPORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1
GLOSSARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1
Appendix A
JUMPER CONFIGURATIONS
Contents
Page
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
JUMPER OPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
CUTTABLE TRACES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-16
OVERVIEW
The ZT 8832 includes several jumper options that tailor the operation
of the board to meet specific application requirements. Options are
selected by installing and removing shorting receptacles (jumpers).
Several less popular options can also be selected by installing or
removing cuttable traces.
This appendix provides detailed descriptions of all jumper and
cuttable trace options, as well as an illustration of the board showing
the locations of all jumpers and cuttable traces.
A-1
Jumper Configurations
JUMPER OPTIONS
Table A-1 below lists the jumpers associated with each option. It also
indicates the pages on which descriptions of these jumpers can be
found.
Table A-2 beginning on page A-3 describes each jumper option in
detail. A dagger (†) in Table A-2 indicates a standard default jumper
configuration.
Figure A-1 on page A-14 shows the factory default jumper
configuration. Figure A-2 on page A-15 provides a blank layout to
document your custom jumper configuration.
Cuttable trace descriptions begin on page A-16.
Table A-1
Jumper Cross Reference.
Function
Jumper(s)
Page(s)
Battery Backup
Board Select
Dual Port RAM
Local RAM
Local ROM
Numeric Data Processor
82050 Serial Port
STD Bus Interrupts
STD Bus I/O
Watchdog Timer
W7,8
W41-43
W28-36
W21,22,26,27
W23-25
W20
W1-6, W9-18
W44-46
W37-40
W19
A-4
A-12
A-8 - A-10
A-6, A-7
A-7
A-6
A-3, A-4
A-13
A-11
A-5
A-2
Jumper Configurations
Table A-2
ZT 8832 Jumper Descriptions.
JUMPER #
DESCRIPTION
W1-W6
J2 DCE/DTE Selection - configures the
82050 serial port for RS-232 Data Terminal
Equipment (DTE) or Data Communication
Equipment (DCE). See also W9-W18
(page A-4). Remove W1-W6 for RS-485
operation.
† DTE
W1
DCE
W1
W2
W2
W3
W3
W4
W4
W5
W5
W6
W6
†Factory default jumper configuration.
A-3
Jumper Configurations
Table A-2
ZT 8832 Jumper Descriptions (continued).
JUMPER #
DESCRIPTION
W7, W8
Battery Backup Device Selection - determines whether the local RAM devices,
RAM LOW and RAM HIGH, are powered
by the battery when the system power is
turned off. Note that this operation is valid
only if the optional battery is present. The
RAM devices must be designed for low
power operation (less than 15 µA data
retention current). Note that the dual port
RAM is always battery-backed if the
battery is installed.
W7
W8
Battery-backed Devices
In
† Out
Out
In
Dual port, RAM LOW, and RAM HIGH
Dual port
W9-15, W18
J2 RS-232/485 Selection - configures the
82050 serial port for RS-232 or RS-485
operation. See also W1-W6 (page A-3) and
W16 and W17 (page A-5).
W9, W10,
W13, W18
In
† Out
†Factory default jumper configuration.
A-4
W11, W12,
W14, W15
Operation
Out
In
Selects RS-485
Selects RS-232
Jumper Configurations
Table A-2
ZT 8832 Jumper Descriptions (continued).
JUMPER #
DESCRIPTION
W16, W17
J2 RS-485 Output Enable - selects the
method of enabling the RS-485 Transmit
Data and Request-To-Send drivers. With
W16 installed, the drivers are disabled.
With both W16 and W17 removed, the
drivers are always enabled. With W17
installed, the drivers are enabled with the
DTR bit of the serial port (I/O port address
3FCh, bit 0). Writing a logical 1 to DTR
enables the drivers and writing a logical 0
disables them. The power-on state of DTR
is a logical 0. See also W1-W6 (page A-3)
and W9-15 and W18 (page A-4).
W16
† In
Out
Out
W19
W17
Operation
Out
In
Out
Always disabled
DTR control
Always enabled
Watchdog Timer.
W19
In
† Out
Operation
Enables watchdog timer
Disables watchdog timer
†Factory default jumper configuration.
A-5
Jumper Configurations
Table A-2
ZT 8832 Jumper Descriptions (continued).
JUMPER #
DESCRIPTION
W20
Numeric Data Processor Interrupt - enables
the Numeric Data Processor (NDP) to
generate a non-maskable interrupt in
response to an exception error. This jumper
must not be installed if the optional NDP is
unplugged.
W20
Operation
In
† Out
W21, W22
W22
† In
In
Out
Out
Enables non-maskable interrupt
Disables non-maskable interrupt
RAM Device Size - selects the address
range of the RAM devices to be plugged
into the RAM LOW and RAM HIGH
sockets. Address ranges are given in
hexadecimal format. See also W7 and W8
(page A-4) and W26 and W27 (page A-7).
W21
Device
RAM LOW RAM HIGH
In
Out
In
Out
32K x 8
128K x 8
512K x 8
Not used
0-07FFFh
0-1FFFFh
0-7FFFFh
---------
†Factory default jumper configuration.
A-6
08000-0FFFFh
20000-3FFFFh
-----------------
Jumper Configurations
Table A-2
ZT 8832 Jumper Descriptions (continued).
JUMPER #
DESCRIPTION
W23-W25
ROM Device Type - configures the ROM
socket for a selected device type. The
ROM address range is fixed from 88000h
through FFFFFh (480 Kbytes). The 8K,
16K, 32K, 64K, 128K, and 256K devices
are redundantly mapped into this address
range, and only 480K of the 512K device is
used.
W23
Out
Out
Out
† In
In
In
In
W26, W27
W24
W25
Device
Out
Out
Out
Out
Out
In
In
In
In
In
In
In
Out
Out
8K x 8
16K x 8
32K x 8
64K x 8
128K x 8
256K x 8
512K x 8
RAM Device Type - configures the RAM
LOW and RAM HIGH sockets for the
selected device type. The address range is
defined by W21 and W22 (page A-6).
W26
† Out
Out
In
W27
Device
In
In
Out
32K x 8
128K x 8
512K x 8 (RAM LOW only)
†Factory default jumper configuration.
A-7
Jumper Configurations
Table A-2
ZT 8832 Jumper Descriptions (continued).
JUMPER #
DESCRIPTION
W28-W32
STD Bus Dual Port RAM Addressing
(20-bit) - defines the address range of the
dual port memory as seen by the STD bus
CPU. These jumpers map the ZT 8832 dual
port RAM into any contiguous 32 Kbyte
block within the 1 Mbyte address range for
an STD bus supporting 20 address lines.
The table on page A-9 shows the address
range of the dual port memory for each
jumper combination. Note that the dual
port memory, as seen by the local CPU, is
mapped at address 80000h through
87FFFh.
See jumpers W33-W36 (page A-10) for
mapping the ZT 8832 into the 16 Mbyte
address space for STD bus CPUs that
support 24 address lines.
A-8
Jumper Configurations
Table A-2
ZT 8832 Jumper Descriptions (continued).
W32
In
In
In
In
In
In
In
In
In
In
In
In
In
In
In
In
Out
Out
Out
Out
Out
Out
Out
Out
Out
†Out
Out
Out
Out
Out
Out
Out
W31
W30
W29
W28
Address Range
In
In
In
In
In
In
In
In
Out
Out
Out
Out
Out
Out
Out
Out
In
In
In
In
In
In
In
In
Out
Out
Out
Out
Out
Out
Out
Out
In
In
In
In
Out
Out
Out
Out
In
In
In
In
Out
Out
Out
Out
In
In
In
In
Out
Out
Out
Out
In
In
In
In
Out
Out
Out
Out
In
In
Out
Out
In
In
Out
Out
In
In
Out
Out
In
In
Out
Out
In
In
Out
Out
In
In
Out
Out
In
In
Out
Out
In
In
Out
Out
In
Out
In
Out
In
Out
In
Out
In
Out
In
Out
In
Out
In
Out
In
Out
In
Out
In
Out
In
Out
In
Out
In
Out
In
Out
In
Out
00000-07FFFh
08000-0FFFFh
10000-17FFFh
18000-1FFFFh
20000-27FFFh
28000-2FFFFh
30000-37FFFh
38000-3FFFFh
40000-47FFFh
48000-4FFFFh
50000-57FFFh
58000-5FFFFh
60000-67FFFh
68000-6FFFFh
70000-77FFFh
78000-7FFFFh
80000-87FFFh
88000-8FFFFh
90000-97FFFh
98000-9FFFFh
A0000-A7FFFh
A8000-AFFFFh
B0000-B7FFFh
B8000-BFFFFh
C0000-C7FFFh
C8000-CFFFFh
D0000-D7FFFh
D8000-DFFFFh
E0000-E7FFFh
E8000-EFFFFh
F0000-F7FFFh
F8000-FFFFFh
†Factory default jumper configuration.
A-9
Jumper Configurations
Table A-2
ZT 8832 Jumper Descriptions (continued).
JUMPER #
DESCRIPTION
W33-W36
STD Bus Dual Port RAM Addressing
(24-bit) - defines the address range of the
dual port memory as seen by the STD bus
CPU. These jumpers, along with W28-W32,
map the ZT 8832 dual port RAM into any
contiguous 32 Kbyte block in the 16 Mbyte
address range for an STD bus supporting 24
address lines. Install cuttable trace CT14 (see
page A-20) to select addressing in the upper
8 Mbytes. Cut CT14 to select the lower
8 Mbytes. CT1 through CT4 must be cut (see
page A-17) before W33-W36 can be used.
CT14
Out
Out
Out
Out
Out
Out
Out
Out
In
In
In
In
In
In
In
† In
W36
W35
W34
W33
Address
Range
Out
Out
Out
Out
Out
Out
Out
Out
In
In
In
In
In
In
In
In
In
In
In
In
Out
Out
Out
Out
In
In
In
In
Out
Out
Out
Out
In
In
Out
Out
In
In
Out
Out
In
In
Out
Out
In
In
Out
Out
In
Out
In
Out
In
Out
In
Out
In
Out
In
Out
In
Out
In
Out
0XXXXXh
1XXXXXh
2XXXXXh
3XXXXXh
4XXXXXh
5XXXXXh
6XXXXXh
7XXXXXh
8XXXXXh
9XXXXXh
AXXXXXh
BXXXXXh
CXXXXXh
DXXXXXh
EXXXXXh
FXXXXXh
†Factory default jumper configuration.
A-10
Jumper Configurations
Table A-2
ZT 8832 Jumper Descriptions (continued).
JUMPER #
DESCRIPTION
W37-W40
STD Bus I/O Port Addressing - defines the
address range of the 16 contiguous I/O
ports as seen by the STD bus CPU.
W40
In
† In
In
In
In
In
In
In
Out
Out
Out
Out
Out
Out
Out
Out
W39
W38
W37
Address Range
In
In
In
In
Out
Out
Out
Out
In
In
In
In
Out
Out
Out
Out
In
In
Out
Out
In
In
Out
Out
In
In
Out
Out
In
In
Out
Out
In
Out
In
Out
In
Out
In
Out
In
Out
In
Out
In
Out
In
Out
FFF0-FFFFh
7FF0-7FFFh
3FF0-3FFFh
1FF0-1FFFh
0FF0-0FFFh
07F0-07FFh
03F0-03FFh
01F0-01FFh
00F0-00FFh
0070-007Fh
0030-003Fh
0010-001Fh
00E0-00EFh
0060-006Fh
0020-002Fh
0000-000Fh
†Factory default jumper configuration.
A-11
Jumper Configurations
Table A-2
ZT 8832 Jumper Descriptions (continued).
JUMPER #
DESCRIPTION
W41-W43
Board Select Addressing - defines the
board address in a board selection scheme
that allows up to seven ZT 8832s to be
mapped into the same STD bus memory
and I/O address space.
W43
† In
In
In
In
Out
Out
Out
Out
W42
W41
Board Address (hex)
In
In
Out
Out
In
In
Out
Out
In
Out
In
Out
In
Out
In
Out
Board select disabled
1
2
3
4
5
6
7
†Factory default jumper configuration.
A-12
Jumper Configurations
Table A-2
ZT 8832 Jumper Descriptions (continued).
JUMPER #
DESCRIPTION
W44-W46
STD Bus Interrupt Selection - defines
which STD bus interrupt request signal is
driven by the ZT 8832.
W44
In
Out
† Out
W45
W46
Interrupt Signal
Out
In
Out
Out
Out
In
INTRQ2* (STD bus pin 50)
INTRQ1* (STD bus pin 37)
INTRQ* (STD bus pin 44)
†Factory default jumper configuration.
A-13
P1
A-14
W28
W29
W30
W31
W32
W33
W34
W35
W36
W37
W38
W39
W40
W41
W42
W43
W44
W45
W46
Figure A–1. ZT 8832 Factory Default Configuration.
ZT 8832 ICP
J4
W23
W24, W25
W26 W27
W20
W21
W22
W16, W17
W15
W9
W10
W11
W12
W13
W14
W7
W1
W2
W3
W4
W5
W6
W8
1
2
J5
3
J1
J2
J3
Jumper Configurations
P1
W28
W29
W30
W31
W32
W33
W34
W35
W36
W37
W38
W39
W40
W41
W42
W43
W44
W45
W46
ZT 8832 ICP
J4
W23
W24, W25
W26 W27
W20
W21
W22
W16, W17
W15
W9
W10
W11
W12
W13
W14
W7
W1
W2
W3
W4
W5
W6
W8
1
2
J5
3
J1
J2
J3
Jumper Configurations
Figure A–2. Jumper Locations.
A-15
Jumper Configurations
CUTTABLE TRACES
The ZT 8832 supports several less popular options with cuttable
traces. Cuttable traces are similar in function to jumper selections.
The difference is that an option change made with a cuttable trace
may require a trace cut and/or a short wire to be soldered between two
pads. Cuttable traces are labeled CTx on the board, where x defines
the cuttable trace number.
Figures A-3 and A-4 on pages A-21 and A-22 illustrate cuttable trace
locations. You may wish to document your custom configuration
using these figures.
Table A-3 below lists the cuttable traces associated with each option.
It also indicates the pages on which descriptions of these cuttable
traces can be found.
Cuttable trace options are summarized in Table A-4 on the following
pages.
"In" next to an entry means the cuttable trace pads are connected.
"Out" means the cuttable trace pads are not connected.
A dagger (†) indicates a standard default configuration.
Table A-3
Cuttable Trace Cross Reference.
Function
Dual Port RAM:
24-Bit Option
Upper or Lower 8 Mbytes
Ground Return
SBX Expansion Module:
Clock Source
Address Expansion
Watchdog Timer
A-16
Trace(s)
Page(s)
CT3-5
CT14
CT10
A-17
A-20
A-20
CT1,2
CT9,11-13
CT7,8
A-17
A-19
A-18
Jumper Configurations
Table A-4
ZT 8832 Cuttable Traces.
TRACE #
DESCRIPTION
CT1, CT2
SBX Expansion Module Clock - selects the
clock for the SBX expansion module. The
default is a 10 MHz 50% duty cycle signal
defined by the Intel SBX expansion module
standard. The optional V40 clock is useful
for custom SBX expansion module designs
that must be synchronized to the local
CPU.
CT1
† In
Out
CT3-CT5
CT3
† In
Out
CT2
Clock
Out
In
10 MHz
V40 CPU
STD Bus Dual Port Memory Addressing
(24-bit) - selects the 24-bit addressing
option for STD bus CPUs that have a
16 Mbyte addressing range. Once CT3CT5 are cut, W33 through W36 become
functional for selecting the appropriate
address range.
CT4
CT5
Operation
In
Out
In
Out
20-bit dual port RAM addressing
24-bit dual port RAM addressing
†Factory default configuration.
A-17
Jumper Configurations
Table A-4
ZT 8832 Cuttable Traces (continued).
TRACE #
DESCRIPTION
CT6
Reserved for Ziatech use.
CT7, CT8
Watchdog Timer Time Out - selects the
delay from the watchdog timer strobe to the
local reset. The watchdog timer includes
two stages. The Stage 1 delay is measured
from the watchdog strobe to the nonmaskable interrupt. The Stage 2 delay is
measured from the watchdog strobe to the
local CPU reset. The time from the nonmaskable interrupt to the local reset is calculated by subtracting the Stage 1 delay
from the Stage 2 delay.
CT7
CT8
Stage 1
Time (ms)
Stage 2
Time (ms)
Stage 2 - Stage 1
Time (ms)
† Out
Out
60 min,
100 max
250 min,
1000 max
150 min,
940 max
In
Out
60 min,
100 max
500 min,
2000 max
400 min,
1940 max
†Factory default configuration.
A-18
Jumper Configurations
Table A-4
ZT 8832 Cuttable Traces (continued).
TRACE #
DESCRIPTION
CT9,
SBX Expansion Module Address Expansion - increases the number of I/O port
addresses available to the SBX expansion
module by increasing the number of
address lines connected to the expansion
module socket. The default connects
address lines A0 through A6, providing 128
I/O port addresses for each of the two
expansion module chip selects. The Intel
SBX MULTIMODULE standard defines
only three address lines, A0, A1, A2. The
remaining address lines are connected as
shown below.
CT11-CT13
CT13
Out
Out
Out
Out
† In
CT12
CT11
CT9
Operation
Out
Out
Out
In
In
Out
Out
In
In
In
Out
In
In
In
In
A0-A2 only
A0-A2 and A3 (J4 pin 30)
A0-A3 and A4 (J4 pin 28)
A0-A4 and A5 (J4 pin 10)
A0-A5 and A6 (J4 pin 24)
†Factory default configuration.
A-19
Jumper Configurations
Table A-4
ZT 8832 Cuttable Traces (continued).
TRACE #
DESCRIPTION
CT10
STD Bus AUX Ground - connects the STD
bus AUX GND signal (P1 pins 53 and 54)
to the STD bus logic GND signal (P1 pins
3 and 4).
CT10
† In
Out
CT14
AUX GND connected to logic ground
AUX GND not connected to logic ground
STD Bus Dual Port RAM Addressing selects between the upper or lower
8 Mbytes for CPUs that have a 16 Mbyte
addressing range. See page A-10.
CT14
† In
Out
†Factory default configuration.
A-20
Operation
Address Range
Upper 8 Mbytes
Lower 8 Mbytes
CT2
CT1
CT5
CT3
ZT 8832 ICP
Jumper Configurations
CT4
Figure A–3. Cuttable Trace Locations, Component Side.
A-21
Jumper Configurations
CT6
CT8
CT7
CT9
CT11
CT12
CT13
CT14
CT10
Figure A–4. Cuttable Trace Locations, Solder Side.
A-22
Appendix B
SPECIFICATIONS
Contents
Page
ELECTRICAL AND ENVIRONMENTAL . . . . . . . . . . . . . . . . . . . . . . . . . B-2
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
DC Operating Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
Battery Backup Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
STD Bus Loading Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-3
MECHANICAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-6
Card Dimensions & Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-6
Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-7
Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-17
TIMING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-22
B-1
Specifications
ELECTRICAL AND ENVIRONMENTAL
Absolute Maximum Ratings
Supply Voltage, Vcc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to 7 V
Supply Voltage, AUX +V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to 13 V
Supply Voltage, AUX -V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to -13 V
Storage Temperature
ZT 8832 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40˚ to +85˚ C
ZT 88CT32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -50˚ to +125˚ C
Operating Temperature
ZT 8832 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0˚ to +65˚ C
ZT 88CT32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40˚ to +85˚ C
DC Operating Characteristics
Supply Voltage, Vcc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.75 to 5.25 V
Supply Voltage, AUX +V . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.4 to 12.6 V
Supply Voltage, AUX -V . . . . . . . . . . . . . . . . . . . . . . . . . . -11.4 to -12.6 V
Supply Current, Vcc (without 8087 numeric data processor)
ZT 8832 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.9 A typ, 1.5 A max
ZT 88CT32 . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 A typ, 0.5 A max
Supply Current, AUX +V . . . . . . . . . . . . . . . . . . 0.05 A typ, 0.10 A max
Supply Current, AUX -V . . . . . . . . . . . . . . . . . . . 0.05 A typ, 0.10 A max
Non-condensing relative humidity . . . . . . . . . . . . . . . . . . . <95% at 40˚ C
Battery Backup Characteristics
Supply Voltage, Vcc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.49 V max
Retention Time
Dual Port RAM only . . . . . . . . . . . . . 6 years min, 10 years typ
Dual Port and Local RAM . . . . . . . . . 2 years min, 5 years typ
(Assuming Local RAMs each have 15 µA max retention current)
B-2
Specifications
STD Bus Loading Characteristics
The unit load is a convenient method for specifying the input and
output drive capability of STD bus cards. In the STD bus systems,
one unit load is equal to one LSTTL load as follows:
•
Maximum high level input current: 20 µA
•
Maximum low level input current: -400 µA
The STD bus unit load reflects input current requirements at worst
case conditions over the recommended supply voltage and ambient
temperature ranges. An output rate at 60 unit loads can drive 60 STD
bus cards having input rated at one unit load.
Table B-1, "ZT 8832 STD Bus Loading, P Connector," includes load
values for STD 32 P pins. Table B-2, "ZT 8832 STD Bus Loading, E
Connector," includes load values for STD 32 E pins.
Notes for Table B-1:
REQ indicates required connection
[1]
High order address bits multiplexed over databus
[2]
PCI connected to PCO
Notes for Table B-2:
REQ indicates required connection
B-3
Specifications
Table B-1
ZT 8832 STD Bus Loading, P Connector.
PIN (CIRCUIT SIDE)
OUTPUT DRIVE
INPUT LOAD
MNEMONIC
+5 VDC
GND
DCPDN*
D7/A13
D6/A22
D5/A21
D4/A20
2
4
6
REQ
REQ
[1]
[1]
[1]
[1]
4
4
4
4
55
55
55
55
1
3
5
8 7
10 9
12 11
14 13
55
55
55
55
REQ
REQ
+5 VDC
GND
VBAT
4
4
4
4
D3/A19
D2/A18
D1/A17
D0/A16
[1]
[1]
[1]
[1]
A15
A14
A13
A12
2
2
2
2
16
18
20
22
15
17
19
21
2
2
2
2
A7
A6
A5
A4
A11
A10
A9
A8
2
2
2
2
24
26
28
30
23
25
27
29
2
2
2
2
A3
A2
A1
A0
RD*
MEMRQ*
BHE
ALE*
2
2
32
34
36
38
31
33
35
37
2
2
WR*
IORQ*
IOEXP
INTRQ1*
STATUS 0*
BUSRQ*
INTRQ*
NMIRQ*
2
40
42
44
46
39
41
43
45
2
STATUS 1*
BUSAK* [2]
INTAK*
WAITRQ*
47
49
51
2
[2]
48
50
52
SYSRESET* [3]
CLOCK* [3]
PCO [4]
REQ
REQ
54
56
53
55
PBRESET*
INTRQ2* (CNTRL*)
PCI [4]
AUX GND
AUX-V
B-4
PIN (COMPONENT SIDE)
OUTPUT DRIVE
INPUT LOAD
MNEMONIC
2
15
15
55
15
15
35
[2]
REQ
REQ
AUX GND
AUX+V
Specifications
Table B-2
ZT 8832 STD Bus Loading, E Connector.
PIN (COMPONENT SIDE)
OUTPUT DRIVE
INPUT LOAD
MNEMONIC
PIN (CIRCUIT SIDE)
OUTPUT DRIVE
INPUT LOAD
MNEMONIC
RSVD
XA23
XA22
XA21
E2
E4
E6
E8
E1
E3
E5
E7
E10
E12
E14
E16
E9
E11
E13
E15
E18
E20
E22
E24
E17
E19
E21
E23
E26
E28
E30
E32
E25
E27
E29
E31
D13
D12
D11
D10
E34
E36
E38
E40
E33
E35
E37
E39
D9
D8
MASTER16*
AENx*
E42
E44
E46
E48
E41
E43
E45
E47
BE3*
BE2*
GND
W-R
E50
E52
E54
E56
E49
E51
E53
E55
BE1*
BE0*
MEM16*
M-IO
E58
E60
E62
E64
E57
E59
E61
E63
DMAIOW*
IO16*
CMD*
EX16*
E66
E68
E70
E72
E65
E67
E69
E71
EXRDY
LOCK*
MAKx*
SLBURST*
E74
E76
E78
E80
E73
E75
E77
E79
XA27*
XA26*
XA25*
XA24*
XA20
RSVD
+5 VDC
DREQx*
GND
D31
D30
D29
D28
GND
D15
D14
REQ
REQ
REQ
REQ
DMAIOR*
EX8*
START*
EX32*
T-C
+5 VDC
MREQx*
MSBURST*
XA31*
XA30*
XA29*
XA28*
REQ
GND
XA19
XA18
XA17
REQ
REQ
XA16
NOWS*
+5 VDC
DAKx*
GND
D27
D26
D25
D24
D23
D22
D21
REQ
REQ
D20
GND
D19
D18
D17
D16
GND
IRQx
B-5
Specifications
MECHANICAL
Card Dimensions & Weight
The ZT 8832 meets the STD 32 bus specification for all mechanical
parameters except for the component lead length protruding from the
back of the board. The specification requires a maximum lead length
of 0.093 inches, but the battery socket pins extend a maximum of
0.150 inches. Be sure the battery socket pins do not touch the adjacent
board when installing the ZT 8832 into the STD bus card cage. In a
card cage with 0.625 inch spacing, the ZT 8832 requires one card slot
without an SBX expansion module installed and two card slots with
an SBX expansion module installed.
Board Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.51 cm ±0.063 cm
(6.500 in ±0.025 in)
Board Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.43 cm ±0.038 cm
(4.500 in ±0.015 in)
Board Thickness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.158 cm ±0.013 cm
(0.062 in ±0.005 in)
Board Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155.9 g (5.5 oz)
Board Height From Top Surface
Without following items . . . . . . . . . . 9.652 mm (0.380 in) max
Including Battery . . . . . . . . . . . . . . . 10.922 mm (0.430 in) max
Including SBX Expansion Module 29.21 mm (1.150 in) max
Board Height From Bottom Surface . . . . . . . . 3.81 mm (0.150 in) max
B-6
Specifications
6.500 +
- 0.025
o
0.015 X 45
CHAMFER 2 PL
0.100 FROM EDGE, NO
COMPONENT PLACEMENT
2 PL
0.400
0.250
0.250
COMPONENT SIDE
3.610
4.500
0.015 X 45 o BEVEL
BOTH EDGES
+0.005
-0.015
0.06 RADIUS MAX 2 PL
0.15 X 45 o CHAM 3 PL
0.445
0.062
TOLERANCES 0.XXX =
Connectors
+-0.005 INCHES
+-0.007
Figure B–1. Board Dimensions.
The ZT 8832 has two card-edge connectors (P and E) and five
headers to interface to the STD bus and application-specific devices
(see Figure B-3). The following pages provide connector descriptions
and pin assignments.
P:
The P connector is the interface between the ZT 8832 and the
STD-80 bus. This connector is a 56-pin (dual 28-pin) cardedge connector with fingers on 0.125 inch centers. The
mating connector is a Viking 3VH28/1CND5 or equivalent
for a three-level wire wrap, or a Viking 3VH28/1CNK5 or
equivalent for the solder tail. Pin assignments are shown on
page B-4.
E:
The E connector extends the P connector to interface the
ZT 8832 to the STD 32 bus. This connector combines with
the P connector to make a 114-pin (dual 57-pin) card-edge
connector with fingers on 0.062 inch centers. The mating
connector is a Viking S3VT68/5DE12 or equivalent for the
card extender, or a Viking S3VT68/5DP12 or equivalent for
the solder tail. Pin assignments are shown on page B-5.
B-7
Specifications
STD 32
STD 32
E13
E14
E15
E16
E17
E18
E19
E20
E21
E22
E23
E24
E25
E26
E27
E28
E29
E30
E31
E32
E33
E34
E35
E36
E37
E38
E39
E40
E41
E42
E43
E44
E45
E46
E47
E48
E49
E50
E51
E52
E53
E54
E55
E56
E57
E58
E59
E60
E61
E62
E63
E64
E65
E66
E67
E68
P01
P02
P03
P04
P05
P07
P06
P08
P09
P10
P11
P12
P13
P14
P15
P16
P17
P18
P19
P20
P21
P22
P23
P24
P25
P26
P27
P28
P29
P30
P31
P32
P33
P34
P35
P36
P37
P38
P39
P40
P41
P42
P43
P44
P45
P46
P47
P48
P49
P50
P51
P52
P53
P54
P55
P56
E69
(Component Side)
E70
(Solder Side)
Figure B–2. STD 32 P/E Connector Pinout.
B-8
J1
J2
2
ZT 8832 ICP
P1
J4
1
J5
3
J3
Specifications
Figure B–3. Connector Locations.
B-9
Specifications
J1:
J1 is a nonlatching 26-pin (dual 13-pin) male transition
connector with 0.1 inch lead spacing. J1 provides 24 digital
I/O lines, fused +5 V ±10%, and ground. Table B-3 on
page B-11 lists the pin assignments. These pin assignments
enable the ZT 90068 cable to connect J1 directly to an I/O
module mounting rack with 8, 16, or 24 positions. For
applications not using this cable, the mating connector is a
T&B Ansley #622-2630 or equivalent.
J2:
J2 is a latching 14-pin (dual 7-pin) male transition connector
with 0.1 inch lead spacing. The 82050 serial port is available
as RS-232-C or RS-422/485 through connector J2. The pin
assignments for RS-232-C are given in Table B-4 on
page B-12, and the pin assignments for RS-422/485 are given
in Table B-5 on page B-13. The mating connector is a T&B
Ansley #622-1430 or equivalent.
J3:
J3 is a latching 10-pin (dual 5-pin) male transition connector
with 0.1 inch lead spacing. The V40 counter/timer and
interrupt inputs are available through connector J3. Table B-6
on page B-14 lists the pin assignments. The mating connector
is a T&B Ansley #622-1030 or equivalent.
J4:
J4 is a 36-pin (dual 18-pin) female SBX connector with
0.1 inch lead spacing. This connector includes the power,
address, data, and control signals needed to add custom I/O to
the ZT 8832. Table B-7 on page B-15 lists the pin
assignments. The mating connector is a Viking 000292-00003
or equivalent.
J5:
J5 is a 3-pin male low profile header with 0.1 inch lead
spacing. The V40 serial port is available through this
connector. Table B-8 on page B-16 lists the pin assignments.
The mating connector is a Molex 39-01-0033 or equivalent.
The mating connector also requires three Molex 39-00-0031
terminals or equivalent.
B-10
Specifications
Table B-3
J1 Parallel Port Pinout.
Pin
Signal
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
MOD24
MOD11
MOD23
MOD10
MOD22
MOD09
MOD21
MOD08
MOD20
MOD07
MOD19
MOD06
MOD18
MOD05
MOD17
MOD04
MOD16
MOD03
MOD15
MOD02
MOD14
MOD01
MOD13
Fused +5 V
MOD12
Ground
Port Address
[hex]
220h bit 7
210h bit 2
220h bit 6
210h bit 1
220h bit 5
210h bit 0
220h bit 4
200h bit 7
220h bit 3
200h bit 6
220h bit 2
200h bit 5
220h bit 1
200h bit 4
220h bit 0
200h bit 3
210h bit 7
200h bit 2
210h bit 6
200h bit 1
210h bit 5
200h bit 0
210h bit 4
——
210h bit 3
——
Note: The pin assignments enable the ZT 90068 cable to connect J1 directly to the
50-pin connector of an I/O module mounting rack.
B-11
Specifications
Table B-4
J2 Serial Port (RS-232-C) Pinout.
DTE
Pin
DCE
3
5
7
9
10
11
12
13
14
1,2,4
6,8
5
3
9
7
10
14
12
13
11
1,2,4
6,8
Signal
Description
TxD
RxD
RTS
CTS
DCD
DSR
RI
GND
DTR
-----
Transmit Data
Receive Data
Request To Send
Clear To Send
Data Carrier Detect
Data Set Ready
Ring Indicator
Ground
Data Terminal Ready
High Impedance
No Connection
Note: The Data Communication Equipment (DCE) and Data Terminal Equipment
(DTE) options are jumper selectable for RS-232-C. The pin assignments enable the
ZT 90014 and ZT 90027 cables to connect J2 directly to a standard 25-pin D shell
connector.
B-12
Specifications
Table B-5
J2 Serial Port (RS-422/485) Pinout.
Pin
Signal
Description
1
2
3
4
11
12
13
14
7,8
5,6,9,10
SDA
SDB
RSA
RSB
CSB
CSA
RDB
RDA
GND
---
Send Data (negative)
Send Data (positive)
Request To Send (negative)
Request To Send (positive)
Clear To Send (positive)
Clear To Send (negative)
Receive Data (positive)
Receive Data (negative)
Ground
No Connection
Note: The J2 pin assignments permit ZT 8832s to be connected together using a
straight cable and rotating one of the connectors 180˚. This same pin assignment is
used on all Ziatech products that support RS-422/485.
B-13
Specifications
Table B-6
J3 Counter/Timer and Interrupt Pinout.
Pin
Signal
Description
2
4
6
8
10
1,3,5,7,9
TCLK
TCTL
TOUT
IRQ6
IRQ7
GND
V40 Counter/Timer Clock Input
V40 Counter/Timer 2 Control Input
V40 Counter/Timer 2 Output
V40 Interrupt Controller Input 6
V40 Interrupt Controller Input 7
Ground
B-14
Specifications
Table B-7
J4 SBX Expansion Module Pinout.
Pin
Signal[1]
Description
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
+12V
-12V
GND
+5V
RESET
MCLK
MA2
MPST*
MA1
RSVD
MA0
MINTR1
IOWRT*
MINTR0
IORD*
MWAIT*
GND
+5 V
MD7
MCS1*
MD6
MCS0*
MD5
RSVD
MD4
TDMA
MD3
OPT1
MD2
OPT0
MD1
MDACK*
MD0
MDRQT
GND
+5V
+12 Volts
-12 Volts
Signal Ground
+5 Volts
Reset
10 MHz Clock[2]
Address 2
Module present[3]
Address 1
Reserved - Address 5[4]
Address 0
Interrupt 1[5]
I/O Write
Interrupt 0[5]
I/O Read
Wait Request
Ground
+5 Volts
Data Bit 7
Chip Select 1[6]
Data Bit 6
Chip Select 0[6]
Data Bit 5
Reserved - Address 6[4]
Data Bit 4
Terminate DMA[3]
Data Bit 3
Option 1 - Address 4[4]
Data Bit 2
Option 0- Address 3[4]
Data Bit 1
DMA Acknowledge[7]
Data Bit 0
DMA Request[7]
Ground
+5 Volts
B-15
Specifications
Notes:
[1] Signals ending with an asterisk are active low and signals without an asterisk are
active high.
[2] The V40 clock is optionally connected to MCLK with CT1 and CT2 (refer to the
cuttable trace description on page A-17). This option is useful for designing SBX
expansion modules synchronous to the ZT 8832 CPU.
[3] These signals are not supported. The MPST* is a no-connect and TDMA is
grounded.
[4] These signals provide additional address lines to the three supported in the
expansion module specification. This feature is supported with CT5 through CT8
as defined in the cuttable trace table starting on page A-16.
[5] Interrupt 1 is routed to IRQ3 of the V40 interrupt controller and Interrupt 0 is
routed to IRQ2 of the V40 interrupt controller.
[6] The I/O address range for Chip Select 0 is 2F8h through 2FFh and the I/O
address range for Chip Select 1 is 300h through 307h. If more than the three
standard I/O address lines are used, Chip Select 0 grows downward and Chip
Select 1 grows upward.
[7] DMA is supported through channel 0 of the V40 DMA controller.
Table B-8
J5 Serial Port Pinout.
Pin
Signal
Description
1
2
3
RxD
TxD
GND
Receive Data
Transmit Data
Ground
Note: The pin assignments enable the ZT 90069 cable to connect J5 directly to a
male 25-pin D shell connector.
B-16
Specifications
Cables
40"+1"
TB ANSLEY
622-1430 FEMALE .025" SQ.
14 PIN CONNECTOR POLARIZED
TB ANSLEY 622-25S FEMALE
25 PIN "D" CONNECTOR
TB ANSLEY
171-25 25 CONDUCTOR
28 GA. STRANDED FLAT
CABLE
TRIM 15-25
AT CONNECTOR
BLUE WIRE
PIN 1
PIN 1
P1
J1
P1
J1
17
5
18
6
19
7
20
1
1
8
2
3
4
5
6
7
14
2
15
3
16
4
9
10
11
12
13
14
Figure B–4. ZT 90014 Rev _ Serial I/O Cable.
B-17
Specifications
305 + 2cm (10' + 0.75")
TB ANSLEY
622-5015
CARD EDGE CONNECTOR
PIN 1
PIN 1
BLUE WIRE
TB ANSLEY
622-0005
POLARIZING
KEY
SEE TABLE FOR
PLACEMENT
TB ANSLEY
622-5030
50 PIN FEMALE
SOCKET
TRANSITION
CONNECTOR
WITH
POLARIZATION
TAB.
TB ANSLEY
171-50 50 CONDUCTOR
28 GA. STRANDED FLAT CABLE
NO. OF MODULES
8
16
24
KEY LOCATION,
BETWEEN PINS
29 AND 31 OR 17 AND 19
11 AND 13
23 AND 25
Figure B–5. ZT 90021 Rev _ Parallel I/O Cable.
100 + 2 cm
PIN 26
PIN 25
PIN 25
TB ANSLEY
622-2630
26-PIN FEMALE
SOCKET
TRANSITION
CONNECTOR
WITH
POLARIZATION
TAB.
TB ANSLEY
622-2630
26-PIN FEMALE
SOCKET
TRANSITION
CONNECTOR
WITH
POLARIZATION
TAB
BLUE WIRE
PIN 1
PIN 2
PIN 1
TB ANSLEY
171-26 26 CONDUCTOR
28 GA. STRANDED FLAT CABLE
Figure B–6. ZT 90090 Rev _ Parallel I/O Cable.
B-18
PIN 26
PIN 2
Specifications
40"+1"
TB ANSLEY
622-1430 FEMALE .025" SQ.
14 PIN CONNECTOR POLARIZED
TB ANSLEY 622-25P MALE
25 PIN "D" CONNECTOR
TB ANSLEY
171-25 25 CONDUCTOR
28 GA. STRANDED FLAT
CABLE
TRIM 15-25
AT CONNECTOR
P1
J1
PIN 1
BLUE WIRE
PIN 1
P1
J1
P1
J1
17
5
18
6
19
7
20
1
1
8
2
3
4
5
6
7
14
2
15
3
16
4
9
10
11
12
13
14
Figure B–7. ZT 90027 Rev _ Serial I/O Cable.
B-19
Specifications
7"
Ref.
32"+ 1.0"
39"+ 1.0"
36"+ 1.0"
AUGAT SIG CONNECTOR (NOTE 2)
INSULATOR: SG113-3G2
DIVIDER: SG20-5P1
RETAINING CLIP: SG70-1P2
NOTE 1
T&B ANSLEY CONNECTOR: 622-5006E
RETAINING CLIP: 622-0006
622-5030
PIN 50 PIN 50
PIN 49
AUGAT
SG20-104P1
(3M 3415-0001)
PIN 49 PIN 49
PIN 50
GROUND CONNECTION PIN
26
25
2
1
KEY (BOTTOM)
AUGAT CABLE KEEPER
SG71-2P1
AUGAT 28 GA. RIBBON CABLE
FH1A-0011-026
PIN 1
P1
PIN 2
PIN 1 PIN 1
PIN 2
J2
J1
PIN 2
J3
NOTE 1: OUTSIDE WIRES REMOVED AT THIS POINT
NOTE 2: CONNECT THE GROUND BUS BARS TOGETHER
NOTE 3: FIRST ARTICLE REQUIRED FOR NEW
VENDOR QUALIFICATION OR PART SUBSTITUTION
Figure B–8. ZT 90068 Rev _ Parallel I/O Cable.
AMP
1 PC. 748051-1 (RECEPTACLE KIT)
1 PC. 747579-8 (FERRULE)
MOLEX
HEATSHRINK TUBING
1 PC. 39-01-0033 (HOUSING)
3 PCS. 39-00-0031 (TERMINALS)
CABLE, 3-WIRE FOIL SHIELD
1.25"
REF
2.25" REF
39"+ 1.0"
-
PIN 1
WHITE
RED
BLACK
CONNECTIONS
PIN 1
25-POSITION PIN 2 TO 3-POSITION PIN 1
25-POSITION PIN 3 TO 3-POSITION PIN 2
25-POSITION PIN 7 TO 3-POSITION PIN 3
25-POSITION PIN 4 TO 25-POSITION PIN 5
25-POSITION PIN 6 TO 25-POSITION PIN 20
(REAR VIEW)
Figure B–9. ZT 90069 Rev _ Serial I/O Cable.
B-20
Specifications
Figure B–10. Standard Assembly Diagram.
B-21
Specifications
TIMING
The ZT 8832 meets the timing requirements outlined in the STD 32
bus specification. The SBX expansion module timings are given on
the following pages. These pages assume the WCY1 and WCY2 V40
configuration registers are programmed to insert two wait states for all
I/O and DMA transfers.
VALID
MA0-MA2
t2
MCS*
t19
t17
t8
MWAIT*
t3
IORD*
t7
t1
t5
t4
VALID
MD0-MDF
t24
Symbol
t1
t2
t3
t4
t5
t7
t8
t17
t19
t24
Parameter
Min
Address setup to read low
Address hold from read high
Read pulse width
Data delay from read low
Data float after read high
Chip select setup to read low
Chip select hold from read high
Wait request pulse width
Wait request delay from chip select
Data hold from wait request
50
30
300
0
0
25
30
0
0
All times given in nanoseconds except where otherwise indicated
Figure B–11. SBX Expansion Module Read Timing.
B-22
Max
250
80
4 ms
75
0
Specifications
MA0-MA2
t11
MCS*
t19
t17
t8
MWAIT*
t25
t7
IOWRT*
t10
t12
t13
t14
MD0-MDF
Symbol
t7
t8
t10
t11
t12
t13
t14
t17
t19
t25
Parameter
Min
Chip select setup to write low
Chip select hold from write high
Address setup to write low
Address hold from write high
Write pulse width
Data setup to write high
Data hold from write high
Wait request pulse width
Wait request delay from chip select
Write delay from wait request
25
30
50
30
300
250
30
0
0
Max
4 ms
75
0
All times given in nanoseconds except where otherwise indicated
Figure B–12. SBX Expansion Module Write Timing.
B-23
Specifications
MDRQT
t22
MDACK*
t20
t21
IORD* OR
IOWRT*
Symbol
t20
t21
t22
Parameter
Min
DMA acknowledge setup to read or write low
DMA acknowledge hold from read or write high
DMA request hold from read or write low
25
30
Max
150
All times given in nanoseconds
Figure B–13. SBX Expansion Module DMA Timing.
t15
t16
MCLK
Symbol
t15
t16
Parameter
Min
Max
Standard clock period
V40 synchronous clock period
Standard clock period high width
V40 synchronous clock high width
100
125
35
55
110
All times given in nanoseconds
Figure B–14. SBX Expansion Module Clock Timing.
B-24
75
Specifications
4.75V
+5 VOLTS
t9 or t18
RESET
Symbol
t9
t18
Parameter
Min
Power up reset pulse width
Reset pulse width
50
50 µs
Max
All times given in nanoseconds except where otherwise indicated
Figure B–15. SBX Expansion Module Reset Timing.
B-25
Appendix C
CUSTOMER SUPPORT
Contents
Page
OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
REVISION HISTORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ZT 8832 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Revision 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Revision 0.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Revision 0.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Revision 0.3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Revision 0.4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Revision 0.5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ZT 88CT32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Revision 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Revision 0.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Revision 0.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Revision 0.3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Revision 0.4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TECHNICAL ASSISTANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RELIABILITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RETURNING FOR SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ZIATECH 5+5 WARRANTY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C-1
C-2
C-2
C-2
C-2
C-2
C-2
C-2
C-3
C-3
C-3
C-3
C-3
C-3
C-3
C-4
C-5
C-6
C-7
OVERVIEW
This appendix offers a product revision history, technical assistance
for the ZT 8832, and the necessary information should you need to
return your ZT 8832 for repair.
C-1
Customer Support
REVISION HISTORY
ZT 8832
Revision 0
The ZT 8832 was originally released on 7/3/89 as Revision 0.
Revision 0.1
There were no functional changes at this revision.
Revision 0.2
A change was made to the ZT 8832 for Revision 0.2 that affects when
the STD bus control port and local control port are reset. The
Revision 0.1 board reset these control ports in response to an STD bus
SYSRESET* only. This implementation caused problems when the
ZT 8832 was used by itself because SYSRESET* was not driven.
The solution implemented in Revision 0.2 was to expand the control
port reset to include the ZT 8832 power monitor, pushbutton, and
Stage 2 watchdog timeout.
Revision 0.3
No functional changes.
Revision 0.4
The STD-80 fingers were replaced with STD 32 fingers.
A 10 kΩ pulldown resistor, R19, was added to the POLL* input on
the V40 processor. The POLL* input is now active low with the 8087
removed instead of floating.
C-2
Customer Support
Support was added for 24-bit addressing in either the upper or the
lower 8 Mbyte region. See page A-10 for more information.
Revision 0.5
No functional changes.
ZT 88CT32
Revision 0
The ZT 88CT32 was originally released as Revision 0.
Revision 0.1
Pullup resistor packs RP7 and RP8 were changed from 100 kΩ to
10 kΩ. This eliminates problems experienced with SBX expansion
modules that drive signals such as wait request with an undetermined
open collector device.
Revision 0.2
No functional changes.
Revision 0.3
See the description of changes for the ZT 8832 Revision 0.4.
Revision 0.4
No functional changes.
C-3
Customer Support
TECHNICAL ASSISTANCE
You can reach Ziatech’s Customer Support Service at the following
number:
Corporate Headquarters: (805) 541-0488
(805) 541-5088 (FAX)
You can also use your modem to leave a message on the 24-hour
Ziatech Bulletin Board Service (BBS) by calling (805) 541-8218. The
BBS will also provide you with current Ziatech product revision and
upgrade information.
C-4
Customer Support
RELIABILITY
Ziatech has taken extra care in the design of the ZT 8832 to ensure
reliability. The four major ways in which reliability is achieved are:
1.
The product was designed in top-down fashion, using the latest
in hardware and software design techniques, so that unwanted
side effects and unclean interactions between parts of the system
are eliminated.
2.
The advanced low-power Schottky TTL devices and the high
speed CMOS TTL devices used in the ZT 8832 are highreliability parts available from several manufacturers.
3.
Ziatech tests each board under power to ensure that the infant
mortality phase is passed before the product is shipped.
4.
Each ZT 8832 has an identification number. Ziatech maintains a
lifetime data base on each board and on the parts used. Any
negative trends in reliability are spotted and Ziatech’s suppliers
are informed and/or changed.
C-5
Customer Support
RETURNING FOR SERVICE
Before returning any of Ziatech’s products, you must obtain a
Returned Material Authorization (RMA) number by calling
(805) 541-0488. We will need the following information to expedite
the shipment of a replacement to you:
1.
Your company name and address for invoice
2.
Shipping address and phone number
3.
Product ID number
4.
If possible, the name of a technically qualified individual at your
company familiar with the mode of failure on the board
If the unit is out of warranty, service is available at a predesignated
service charge. Contact Ziatech for pricing and please supply a
purchase order number for invoicing the repair.
Pack the ZT 8832 in anti-static material and ship in a sturdy
cardboard box with enough packing material to adequately cushion
the board. Any product returned to Ziatech improperly packed will
immediately void the warranty for that particular product! Mark the
RMA number clearly on the outside of the box before returning.
C-6
Customer Support
ZIATECH 5+5 WARRANTY
FIVE-YEAR LIMITED WARRANTY
Products manufactured by Ziatech Corporation are covered from the date of
purchase by a five-year warranty against defects in materials, workmanship,
and published specifications applicable to the date of manufacture. During
the warranty period, Ziatech will repair or replace, solely at its option,
defective units provided they are returned at customer expense to an
authorized Ziatech repair facility. Products which have been subjected to
misuse, abuse, neglect, alteration, or unauthorized repair, determined at the
sole discretion of Ziatech, whether by accident or otherwise, are excluded
from warranty. The warranty on fans and disk drives is limited to two years
and the warranty on flat panel displays is limited to nine months from date
of purchase. Other products and accessories not manufactured by Ziatech
are limited to the warranty provided by the original manufacturer.
Consumable items (fuses, batteries, etc.) and software are not covered by
this warranty. Within 90 days of shipping date, Ziatech will replace software
disk media should it prove defective.
Ziatech may offer, where applicable and available, replacement products;
otherwise, repairs requiring components, assemblies, and other purchased
materials may be limited by market availability.
Ziatech assumes no liability resulting from changes to government
regulations affecting use of materials, equipment, safety, and methods of
repair. Ziatech may, at its discretion, offer replacement products.
THE ABOVE WARRANTY IS IN LIEU OF ANY OTHER WARRANTY,
WHETHER EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING,
BUT NOT LIMITED TO, ANY WARRANTY FOR FITNESS OF
PURPOSE, MERCHANTABILITY, OR FREEDOM FROM INFRINGEMENT OR THE LIKE, AND ANY WARRANTY OTHERWISE ARISING
OUT OF ANY PROPOSAL, SPECIFICATIONS, OR SAMPLE.
Ziatech neither assumes nor authorizes any person to assume for it any other
liability. The liability of Ziatech under this warranty agreement is limited to
a refund of the purchase price. In no event shall Ziatech be liable for loss of
profits, use, incidental, consequential, or other damage, under this
agreement.
C-7
Customer Support
SPECIAL EXTENDED WARRANTY OPTION
In addition to the standard five-year warranty, Ziatech offers, for a
nominal fee, an extended period of warranty up to five extra years.
This extended warranty period provides similar coverage and
conditions as stated above in the five-year limited warranty
agreement.
LIFE SUPPORT POLICY
Ziatech products are not authorized for use as critical components in
life support devices or systems without the express written approval
of the president of Ziatech Corporation. As used herein:
1.
Life support devices or systems are devices or systems which
support or sustain life, and whose failure to perform, when
properly used in accordance with instructions for use provided in
the labeling, can be reasonably expected to result in a significant
injury to the user.
2.
A critical component is any component of a life support device
or system whose failure to perform can be expected to cause the
failure of the life support device or system, affect its safety, or
limit its effectiveness.
C-8
Appendix D
GLOSSARY
backplane
The edge of the board that inserts into the STD
bus connector. This term is generally used to
define the location of signals that are routed
across the STD bus.
BAU
Bus Arbitration Unit. Section of the CPU that
controls which internal or external bus master
has access to the buses at any given time.
BCD
Binary Coded Decimal. Representation of the
cardinal numbers 0 through 9 by ten binary
codes. Each binary code is 4 binary digits long.
BIU
Bus Interface Unit. Section of the CPU that
controls the external address, data, and control
buses.
CGU
Clock Generator Unit. Section of the CPU that
provides a clock reference with a 50% duty
cycle to the CPU.
CMOS
Complementary Metal Oxide Semiconductor.
Provides low power density and high noise
immunity.
D-1
Glossary
CNTRL*
Control. This STD bus signal (pin 50) was used
in previous designs for special clock timing on
peripheral boards. It may also be used as an
interrupt request, INTRQ2*, on the backplane.
DCE
Data Communication Equipment. One of two
possible orientations (DCE or DTE) for drivers
and receivers in the RS-232-C serial communications protocol.
DCU
DMA Control Unit. Section of the CPU that
controls high speed data transfer between I/O
and memory devices.
DMA
Direct Memory Access. Used for faster data
transfer rate when processing of I/O data on a
byte-by-byte basis is not required.
DTE
Data Terminal Equipment. One of two possible
orientations (DCE or DTE) for drivers and
receivers in the RS-232-C serial communications protocol.
EOI
End Of Interrupt. A byte sent to the interrupt
controller that signifies the interrupt level has
been serviced.
EPROM
Erasable Programmable Read-Only Memory.
Memory is programmed and erased with ultraviolet light.
D-2
Glossary
frontplane
The edge of the board on which the extractor is
located, opposite to the backplane. This term is
generally used to define the location of user
interface signals.
ICU
Interrupt Control Unit, on the V40 CPU.
INTRQ*
INTRQ1*
INTRQ2*
Interrupt Requests. These STD-80 signals are
processor card input signals that conditionally
interrupt the program when enabled by a specific program instruction. INTRQ2* was formerly
called CNTRL*; see CNTRL*.
LSTTL
Low Power Schottky Transistor Transistor
Logic. See Schottky TTL.
mark
A negative voltage on a serial link.
NMI
Non-Maskable Interrupt. Interrupt request input
that cannot be disabled through software control.
Generally used to signal events such as power
failure and parity error.
NMIRQ*
Non-Maskable Interrupt Request. STD bus
signal (pin 46) that generates an NMI. See NMI.
PIC
Programmable Interrupt Controller (on the
ZT 8802, equivalent to the Intel 8259A). This
device prioritizes and handles interrupt requests
from the STD bus.
pop
A stack operation that retrieves one byte from
the top of the processor stack.
D-3
Glossary
prefetch
Instructions are fetched and stored into a queue
on the microprocessor prior to execution in
order to optimize performance.
push
A stack operation that stores one byte onto the
top of the processor stack.
RS-232-C
An acronym for Required Standard 232 of the
Electronics Industry Association. Interface
standard between Data Terminal Equipment and
Data Communication Equipment, employing
serial binary data exchange.
RS-485
Standard for electrical characteristics of
hardware drivers and receivers for use in
balanced multipoint systems.
Schottky TTL
Provides high speed, low noise, and compatibility with standard TTL. See TTL.
SCU
Serial Control Unit. Single asynchronous serial
channel used for serial communication between
the CPU and a serial device external to the CPU.
space
A positive voltage on a serial link.
TCU
Timer/Counter Control Unit on the V40 CPU.
TTL
Transistor-Transistor Logic.
VCR
V40 Configuration Registers. Twelve programmable registers used to configure the CPU to
meet the needs of varying applications.
D-4
Glossary
WCU
Wait Control Unit. Section of the CPU that can
define a different number of wait states for each
of the three areas of the memory space.
D-5
INDEX
-AACC - Asynchronous Communication Controller . . . . . . . . . . . 1-8, 11-1
asynchronous data format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-21
baud rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-22
block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4
DCE/DTE jumper configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
frontplane connector J2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-3, B-10
functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4
interrupt and polled communication . . . . . . . . . . . . . . . . . . . . . . . . . 11-23
operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-20
programmable registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-7
programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-24
register summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-25
reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-20
RS-485 operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-23
access time
local RAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11
local ROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10
Address Adjuster (V40 DCU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5
Address register (V40 DCU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5
application examples
peripheral initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
V40 initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
watchdog timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
autoinitialization (DMA transfers) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-18
AUX GND/logic ground connection (cuttable trace) . . . . . . . . . . . . A-20
i
Index
-Bbackplane, definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1
battery backup for local RAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
jumper configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
BAU - Bus Arbitration Unit (V40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19
definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1
baud rate
82050 serial port (82050 ACC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-22
V40 serial port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-13
Binary Coded Decimal (BCD), definition . . . . . . . . . . . . . . . . . . . . . . . . D-1
BIU - Bus Interface Unit (V40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19
definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1
block diagram, ZT 8832 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
board select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7, 3-5, 3-15
board addressing jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-12
I/O address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
bus loading characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-3
-Ccables
DOS MPX requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
STD ROM requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
ZT 90021 parallel I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-18
ZT 90068 parallel I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-20
ZT 90090 parallel I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-18
ZT 90014 serial I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-17
ZT 90027 serial I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-19
ZT 90069 serial I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5, B-20
CGU - Clock Generator Unit (V40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20
definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1
check index instruction (V40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-33
Clock Select and Divisor (V40 TCU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5
CMOS
characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6, 5-3
ii
Index
definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1
CNTRL* (INTRQ2*), definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-2
commonly asked questions, ZT 8832 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
connectors
connector locations drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-9
J4 (custom I/O) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-4, B-10
J1 (parallel I/O) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-2, B-10
J2 (82050 serial port) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-3, B-10
J3 (V40 counter/timer & interrupt inputs) . . . . . . . . . . . 7-3, 8-3, B-10
J5 (V40 serial port) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-2, B-10
P and E (STD bus interface) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-7
Control Logic
ICU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6
TCU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6
control port
local . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
STD bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
Control registers (V40 DCU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-6
Count Adjuster (V40 DCU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-6
counter/timers (V40; see TCU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
frontplane connector J3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
count latch command (V40 TCU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14
count modes 0-5 (V40 TCU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-16
count registers (V40 TCU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12
Count register (V40 DCU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-6
CPU - Central Processing Unit (V40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
enhanced architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18
registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23
standby mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18
CT1,CT2 (SBX expansion module clock) . . . . . . . . . . . . . . . . . . . . . . A-17
CT3-CT5 (STD bus dual port memory addressing, 24-bit) . . . . . . A-17
CT6 (reserved) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-18
CT7, CT8 (watchdog timer time out) . . . . . . . . . . . . . . . . . . . . . . . . . . . A-18
CT9, CT11-CT13 (SBX expansion module address
expansion) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-19
iii
Index
CT10 (STD bus AUX GND) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-20
CT14 (STD bus dual port RAM addressing) . . . . . . . . . . . . . . . . . . . . A-20
customer support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1
custom I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-2
frontplane connector J4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-4, B-10
cuttable traces (see CT1, CT2, etc.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-17
-DDBA/DCA - DMA Base and Current Address registers . . . . . . . . . . 9-11
DBC/DCC - DMA Base and Current Count registers . . . . . . . . . . . . 9-10
DCE (data communication equipment) (see DCE/DTE) . . . . . . . . . . 1-8
DCE/DTE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8, 11-3
definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-2
selecting via jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
selecting with serial cable in J2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-24
serial port pinouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-12
DCH - DMA Channel register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-8
DCU - DMA Control Unit (V40) . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22, 9-1
autoinitialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-18
block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-4
definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-2
functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-4
I/O port addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13, 9-7
operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-17
programmable registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-7
programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-18
reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-17
DDC - DMA Device Control register . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-12
development systems (see STD ROM, DOS MPX) . . . . . . . . . . . . . . . 1-4
device driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
DICM - DMA Initialize Command register . . . . . . . . . . . . . . . . . . . . . . 9-8
dimensions of the ZT 8832 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-6
direct memory access (DMA), definition . . . . . . . . . . . . . . . . . . . . . . . . D-2
divide error interrupt (V40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-31
Divisor Latch (82050 ACC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-17
iv
Index
DMA controller (V40) (see DCU - DMA Control Unit) . . . . . . . . . . 9-1
DMD - DMA Mode register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-13
DMK - DMA Mask register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-16
DOS MPX development system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4, 3-3
installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
jumper configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
DST - DMA Status register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-15
DTE (data terminal equipment) (see DCE/DTE) . . . . . . . . . . . . . . . . . 1-8
dual port RAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7, 2-10, 3-5, 3-8
addressing (24-bit) – cuttable traces . . . . . . . . . . . . . . . . . . . . . . . . . A-17
addressing (20-bit) selection jumpers . . . . . . . . . . . . . . . . . . . . . . . . . A-8
addressing (24-bit) selection jumpers . . . . . . . . . . . . . . . . . . . . . . . . A-10
addressing upper or lower 8 Mbytes (cuttable traces) . . . . . . . . . A-20
battery backup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
memory map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11
DULA - DMA Unit Low Address register . . . . . . . . . . . . . . . . . . . . . . . 6-5
-EE and P connectors (STD bus interface) . . . . . . . . . . . . . . . . . . . . . . . . . B-7
electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
emulation mode (8080) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-34
emulator manufacturers for NEC V40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
environmental specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
EOI (end of interrupt), definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-2
EPROM, definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-2
expansion module (see SBX expansion module) . . . . . . . . . . . . . . . . 14-1
-Ffeatures of the ZT 8832 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
fixed vector instruction (V40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-32
frontplane, definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-3
functional blocks, ZT 8832 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
v
Index
-Ggetting started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1
-IICU - Interrupt Control Unit (V40) . . . . . . . . . . . . . . 1-9, 3-17, 5-22, 8-1
automatic priority rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-28
block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-3
frontplane connector J3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3, B-10
frontplane interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3
interrupt masking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-30
interrupt nesting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-22
interrupt status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-31
interrupt vectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30, 8-21
I/O port addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
level- or edge-triggered interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-25
non-maskable interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-32
operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-19
processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29
programmable registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-7
programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-31
reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-19
selection jumpers for STD bus interrupts . . . . . . . . . . . . . . . . . . . . A-13
STD bus interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
input buffer (parallel I/O) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-4
installable device driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
installing the ZT 8832
with DOS MPX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
with STD ROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Internal Bus Interface (V40 DCU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5
Interrupt Control block (82050 ACC) . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-6
vi
Index
Interrupt Enable register (82050 ACC) . . . . . . . . . . . . . . . . . . . . . . . . 11-19
Interrupt Generation Logic (V40 SCU) . . . . . . . . . . . . . . . . . . . . . . . . . 10-4
Interrupt Identify register (82050 ACC) . . . . . . . . . . . . . . . . . . . . . . . . 11-18
Interrupt Initialization Words 1-4 (IIW1-IIW4) . . . . . . . . . . . . . . 8-6, 8-8
Interrupt In-Service register (V40 ICU) . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
Interrupt Mask register (V40 ICU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
Interrupt Request register (V40 ICU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
interrupts (see also ICU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9, 3-17
Interrupt Status Port (ISP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18
introduction to ZT 8832 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
INTRQ*, INTRQ1*, INTRQ2* (CNTRL*)*, definitions . . . . . . . . D-3
I/O
addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
addressing selection jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-11
custom I/O (connector J4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-4, B-10
mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12, 5-24
mixing I/O in a single port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-7
parallel (see parallel I/O) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1
serial - 82050 (see ACC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1
serial - V40 (see SCU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1
IULA - Interrupt Unit Low Address register . . . . . . . . . . . . . . . . . . . . . . 6-5
-JJ1 parallel I/O connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-2, B-10
J2 82050 serial port connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-3, B-10
J3 V40 counter/timer & interrupt inputs connector . . . . . 7-3, 8-3, B-10
J4 custom I/O connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-4, B-10
J5 V40 serial port connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-2, B-10
jumpers (see also W1, W2, etc.)
DOS MPX requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
factory default configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-14
jumper descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
STD ROM requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
vii
Index
-LLight Emitting Diode (LED) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-2
programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-7
Line Control register (82050 ACC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-8
Line Status register (82050 ACC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-11
local control port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
I/O address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
maskable and non-maskable interrupts . . . . . . . . . . . . . . . . . . . . . . . 3-14
local memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6, 2-10, 3-5
access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
battery backup (jumper selection) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
device size selection jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-6
device type selection jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-7
DOS MPX memory requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10
STD ROM memory requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
local ROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10
device type selection jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-7
lock access to dual port RAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11, 3-14
LSTTL, definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-3
-Mmark, definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-3
maskable interrupt
for local control port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14
for STD bus control port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
mechanical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-6
memory (see also dual port RAM & local memory)
DOS MPX requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
dual port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
local . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10, 5-24
STD ROM requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
microprocessor - see V40 processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
viii
Index
Modem Control block (82050 ACC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-6
Modem Control register (82050 ACC) . . . . . . . . . . . . . . . . . . . . . . . . . 11-13
Modem Status register (82050 ACC) . . . . . . . . . . . . . . . . . . . . . . . . . . 11-15
Mode register (V40 TCU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5
modes 0-5 (count modes, V40 TCU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-16
mounting racks for I/O modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-2
multiple latch command (V40 TCU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-15
-NNMI (Non-Maskable Interrupt) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-32
definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-3
NMIRQ* (Non-Maskable Int. Req.) definition . . . . . . . . . . . . . . . . . . . D-3
non-maskable interrupt
for local control port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14
for STD bus control port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
Numeric Data Processor (NDP) . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10, 15-1
interrupt (jumper selection) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-6
-OOPCN - On Chip Peripheral Connection register . . . . . . . . . . . . . . . . . 6-3
operating requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
operation words for ICU (IMKW, IPFW, IMDW) . . . . . . . . . . 8-6, 8-12
OPHA - On Chip Peripheral High Address register . . . . . . . . . . . . . . . 6-5
OPSEL - On Chip Peripheral Selection register . . . . . . . . . . . . . . . . . . 6-4
Opto 22 I/O module mounting rack . . . . . . . . . . . . . . . . . . . . . . . . 1-8, 12-2
output buffer (parallel I/O) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-4
output latch (parallel I/O) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-3
overflow interrupt (V40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-32
-Ppacking list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
P and E connectors (STD bus interface) . . . . . . . . . . . . . . . . . . . . . . . . . B-7
parallel I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8, 12-1
block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-3
ix
Index
frontplane connector J1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-2, B-10
functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-3
I/O module mounting racks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-2
mixing I/O in a single port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-7
operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-6
programmable registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-5
programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-6
reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-6
watchdog strobe function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-2
pop (stack operation) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-31
definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-3
prefetch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9
definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-4
Priority Resolver for interrupt requests . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
processor - see V40 processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
product definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
programmable interrupt controller (PIC), definition . . . . . . . . . . . . . . D-3
programmable reset for STD bus control port . . . . . . . . . . . . . . . . . . . 3-12
push (stack operation) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-31
definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-4
-RRAM LOW/RAM HIGH
battery backup (jumper selection) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
device size selection jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-6
device type selection jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-7
DOS MPX memory requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
STD ROM memory requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
RAM (see dual port RAM or local memory) . . . . . . . . . . . . . . . . . . . . . 1-6
Read/Write Control Logic
ACC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-5
ICU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6
SCU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4
TCU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
Receiver
ACC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-5
x
Index
V40 SCU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4
reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-5
reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21
devices affected by reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23
return for service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-6
revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-2
RFC - Refresh Control register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10
RMA (Returned Material Authorization) . . . . . . . . . . . . . . . . . . . . . . . . C-6
ROM socket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10
device type selection jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-7
RS-485
definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-4
operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-23
output enable (jumper selection) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5
selection jumpers, RS-485 vs. RS-232-C . . . . . . . . . . . . . . . . . . . . . A-4
serial port pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-13
RS-232-C
definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-4
selection jumpers, RS-232-C vs. RS-485 . . . . . . . . . . . . . . . . . . . . . A-4
serial port pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-12
-SSBX expansion module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10, 3-5, 14-1
address expansion (cuttable traces) . . . . . . . . . . . . . . . . . . . . . . . . . . A-19
clock duty cycle (cuttable traces for selection) . . . . . . . . . . . . . . . A-17
custom I/O (frontplane connector J4) . . . . . . . . . . . . . . . . . . . . . . . . . 14-2
I/O address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
Schottky TTL, definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-4
SCM - Serial Command register (V40 SCU) . . . . . . . . . . . . . . . . . . . . 10-8
SCU - Serial Control Unit (V40) . . . . . . . . . . . . . . . . . . . . . 1-8, 5-21, 10-1
asynchronous data format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-12
baud rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-13
block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3
definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-4
frontplane connector J5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-2, B-10
functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3
xi
Index
I/O port addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-11
programmable registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5
programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-16
reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-11
segment registers (V40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8
serial communications - 82050 (see ACC) . . . . . . . . . . . . . . . . . . . . . . 11-1
serial communications - V40 (see SCU) . . . . . . . . . . . . . . . . . . . . . . . . 10-1
SIMK - Serial Interrupt Mask register (V40 SCU) . . . . . . . . . . . . . 10-10
single-step interrupt (V40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-31
SMD - Serial Mode register (V40 SCU) . . . . . . . . . . . . . . . . . . . . . . . . 10-9
software support
DOS MPX development system . . . . . . . . . . . . . . . . . . . . . 1-4, 2-7, 3-3
STD ROM development system . . . . . . . . . . . . . . . . . . . . . 1-4, 2-5, 3-3
space, definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-4
specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
SST - Serial Status register (V40 SCU) . . . . . . . . . . . . . . . . . . . . . . . . . 10-6
status registers (V40 TCU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12
status words for ICU (IRQ, IIS, IPOL) . . . . . . . . . . . . . . . . . . . . . . . . . . 8-16
STD bus
AUX GND/logic ground cuttable trace . . . . . . . . . . . . . . . . . . . . . . A-20
board select addressing jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-12
control port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12, 3-9
dual port RAM addressing (24-bit) cuttable traces . . . . . . . . . . . . A-17
dual port RAM addressing (20-bit) selection jumpers . . . . . . . . . . A-8
dual port RAM addressing (24-bit) selection jumpers . . . . . . . . A-10
dual port RAM address range (cuttable traces) . . . . . . . . . . . . . . . A-20
interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17, 8-4
interrupt selection jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-13
I/O port address selection jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . A-11
P and E connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-7
unit load characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-3
STD ROM development system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4, 3-3
installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
jumper configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
SULA - Serial Unit Low Address register . . . . . . . . . . . . . . . . . . . . . . . . 6-5
xii
Index
system requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
-TTCKS - Timer Clock Selection register . . . . . . . . . . . . . . . . . . . . . . . . . 6-10
TCU - Counter/Timer Control Unit (V40) . . . . . . . . . . . . . 1-9, 5-21, 7-1
block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-4
frontplane connector J3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-10
functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
I/O port addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13, 7-7
operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14
programmable registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7
programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-28
reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14
technical assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-4
theory of operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
timer (see watchdog timer) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1
timing diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-22
TMD - Timer Mode register (V40 TCU) . . . . . . . . . . . . . . . . . . . . . . . . . 7-8
transmit and receive buffers (82050 ACC) . . . . . . . . . . . . . . . . . . . . . . 11-8
Transmitter
ACC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-5
V40 SCU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4
TTL, definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-4
TULA - Timer/Counter Low Address register . . . . . . . . . . . . . . . . . . . . 6-5
-Uunpacking the ZT 8832 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
-Vvariable vector interrupt instruction (V40) . . . . . . . . . . . . . . . . . . . . . . 5-33
VCR - V40 Configuration Registers . . . . . . . . . . . . . . . . . . . 5-20, 6-2, D-4
V40 processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6, 5-2
BAU - Bus Arbitration Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19
xiii
Index
BIU - Bus Interface Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19
block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
CGU - Clock Generator Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20
commonly asked questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
configuration registers for I/O mapping . . . . . . . . . . . . . . . . . . . . . . 2-12
CPU - Central Processing Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
data formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25
DCU - DMA Control Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
emulator manufacturers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
functional blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
ICU - Interrupt Control Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
instruction set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-27
I/O addressing and map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26
memory addressing and map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-24
reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23, 6-12
SCU - Serial Control Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21
TCU - Counter/Timer Control Unit . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21
VCR - V40 Configuration Registers . . . . . . . . . . . . . . . . 5-20, 6-2, D-4
WCU - Wait Control Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21
-WW1-6 (J2 DCE/DTE selection) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
W7, W8 (battery backup device selection) . . . . . . . . . . . . . . . . . . . . . . . A-4
W9-15, W18 (J2 RS-232/485 selection) . . . . . . . . . . . . . . . . . . . . . . . . . A-4
W16, 17 (J2 RS-485 output enable) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5
W19 (watchdog timer) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5
W20 (NDP interrupt) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-6
W21,W22 (RAM device size) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-6
W23-W25 (ROM device type) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-7
W26,W27 (RAM device type) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-7
W28-W32 (STD bus dual port RAM addressing, 20-bit) . . . . . . . . . A-8
W33-W36 (STD bus dual port RAM addressing, 24-bit) . . . . . . . . A-10
W37-W40 (STD bus I/O port addressing) . . . . . . . . . . . . . . . . . . . . . . A-11
xiv
Index
W41-W43 (board select addressing) . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-12
W44-W46 (STD bus interrupt selection) . . . . . . . . . . . . . . . . . . . . . . . A-13
wait-state generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-7
watchdog timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1
introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
jumper selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5
strobe via parallel port signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-2
time out delay (cuttable traces) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-18
WCU - Wait Control Unit (V40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21
definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-5
WCY1 - Wait Cycle 1 register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
WCY2 - Wait Cycle 2 register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
what’s in the box - unpacking the ZT 8832 . . . . . . . . . . . . . . . . . . . . . . . 2-2
WMB - Wait Memory Boundary register . . . . . . . . . . . . . . . . . . . . . . . . . 6-9
-ZzSBX expansion module (see SBX expansion module) . . . . . . . . . . 14-1
ZT 2226 I/O module mounting rack . . . . . . . . . . . . . . . . . . . . . . . . 1-8, 12-2
ZT 8832 vs. ZT 8830 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
ZT 90014 serial I/O cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-17
ZT 90021 parallel I/O cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-18
ZT 90027 serial I/O cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-19
ZT 90068 parallel I/O cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-20
ZT 90069 serial I/O cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5, B-20
ZT 90090 parallel I/O cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-18
ZT 88CT32
operating requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-3
specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
xv
Download PDF