User guide | ARM CM940T Computer Hardware User Manual

ARM Integrator/CM940T
User Guide
ARM DUI 0125A
ARM Integrator/CM940T
User Guide
© Copyright ARM Limited 1999. All rights reserved.
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Change
8 September1999
A
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© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Electromagnetic conformity
This section contains electromagnetic conformity (EMC) notices.
Federal Communications Commission Notice
NOTE: This equipment has been tested and found to comply with the limits for a class
A digital device, pursuant to part 15 of the FCC rules. These limits are designed to
provide reasonable protection against harmful interference when the equipment is
operated in a commercial environment. This equipment generates, uses, and can radiate
radio frequency energy and, if not installed and used in accordance with the instruction
manual, may cause harmful interference to radio communications. Operation of this
equipment in a residential area is likely to cause harmful interference in which case the
user will be required to correct the interference at his own expense.
CE Declaration of Conformity
This equipment has been tested according to ISE/IEC Guide 22 and EN 45014. It
conforms to the following product EMC specifications:
The product herewith complies with the requirements of EMC Directive 89/336/EEC
as amended.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
iii
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© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Contents
ARM Integrator/CM940T User Guide
Electromagnetic conformity ............................................................................................iii
Preface
About this document .................................................................................................... viii
Further reading............................................................................................................... x
Feedback .......................................................................................................................xi
Chapter 1
Introduction
1.1
1.2
1.3
1.4
1.5
Chapter 2
Getting Started
2.1
2.2
Chapter 3
Setting up a standalone ARM Integrator/CM940T ........................................ 2-2
Attaching the ARM Integrator/CM940T to a motherboard............................. 2-5
Hardware Description
3.1
3.2
3.3
3.4
ARM DUI 0125A
About the ARM Integrator/CM940T core module.......................................... 1-2
ARM Integrator/CM940T overview................................................................ 1-4
Links and indicators ...................................................................................... 1-8
Test points .................................................................................................. 1-10
Precautions ................................................................................................. 1-11
ARM940T microprocessor core .................................................................... 3-2
SSRAM controller ......................................................................................... 3-3
Core module FPGA....................................................................................... 3-4
SDRAM controller ......................................................................................... 3-6
© Copyright ARM Limited 1999. All rights reserved.
v
3.5
3.6
3.7
3.8
Chapter 4
Programmer’s Reference
4.1
4.2
4.3
4.4
Appendix A
HDRA ........................................................................................................... A-2
HDRB ........................................................................................................... A-4
Specifications
B.1
B.2
B.3
vi
Memory organization .................................................................................... 4-2
Exception vector mapping ............................................................................ 4-6
Core module registers .................................................................................. 4-7
Interrupt registers ....................................................................................... 4-19
Signal Descriptions
A.1
A.2
Appendix B
Reset controller ............................................................................................ 3-8
System bus bridge...................................................................................... 3-11
Clock generators ........................................................................................ 3-17
Multi-ICE support........................................................................................ 3-21
Electrical specification .................................................................................. B-2
Timing specification ...................................................................................... B-3
Mechanical details ........................................................................................ B-4
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Preface
This preface introduces the ARM Integrator/CM940T core module and its reference
documentation. It contains the following sections:
•
About this document on page viii
•
Further reading on page x
•
Feedback on page xi.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
vii
About this document
This document describes how to set up and use the ARM Integrator/CM940T core
module.
Intended audience
This document has been written for experienced hardware and software developers to
aid the development of ARM-based products using the ARM Integrator/CM940T as
part of a development system.
Organization
This document is organized into the following chapters:
Chapter 1
Introduction
Read this chapter for an introduction to the core module.
Chapter 2
Getting Started
Read this chapter for a description of how to set up and start using the
core module.
Chapter 3
Hardware Description
Read this chapter for a description of the header’s hardware architecture,
including clocks, resets, and debug.
Chapter 4
Programmer’s Reference
Read this chapter for a description of the header memory map and
registers.
Appendix A Signal Descriptions
Refer to this appendix for a description of the signals on the HDRA and
HDRB connectors.
Appendix B Specifications
Refer to this appendix for electrical, timing, and mechanical
specifications.
viii
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Typographical conventions
The following typographical conventions are used in this document:
bold
Highlights ARM processor signal names within text, and interface
elements such as menu names. May also be used for emphasis in
descriptive lists where appropriate.
italic
Highlights special terminology, cross-references and citations.
typewriter
Denotes text that may be entered at the keyboard, such as
commands, file names and program names, and source code.
typewriter
Denotes a permitted abbreviation for a command or option. The
underlined text may be entered instead of the full command or
option name.
typewriter italic
Denotes arguments to commands or functions where the argument
is to be replaced by a specific value.
typewriter bold
Denotes language keywords when used outside example code.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
ix
Further reading
This section lists related publications by ARM Limited and other companies that may
provide additional information.
ARM publications
The following publications provide information about related ARM products and
toolkits:
•
ARM740T Technical Reference Manual (DDI 0008)
•
ARM Integrator/AP User Guide (ARM DUI 0098)
•
ARM Integrator/SP User Guide (ARM DUI 0099)
•
ARM Multi-ICE User Guide (ARM DUI 0048)
•
AMBA Specification (ARM IHI 0011)
•
ARM Architectural Reference Manual (ARM DDI 0100)
•
ARM Firmware Suite Reference Guide (ARM DUI 0102)
•
ARM Software Development Toolkit User Guide (ARM DUI 0040)
•
ARM Software Development Toolkit Reference Guide (ARM DUI 0041)
•
ADS Tools Guide (ARM DUI 0067)
•
ADS Debuggers Guide (ARM DUI 0066)
•
ADS Debug Target Guide (ARM DUI 0058)
•
ADS Developer Guide (ARM DUI 0056)
•
ADS CodeWarrior IDE Guide (ARM DUI 0065).
Other publications
The following publication provides information about the clock controller chip used on
the Integrator modules:
•
MicroClock OSCaR User Configurable Clock Data Sheet (MDS525),
MicroClock Division of ICS, San Jose, CA.
The following publications provide information and guidelines for developing products
for Microsoft Windows CE:
•
Standard Development Board for Microsoft® Windows® CE, 1998,
Microsoft Corporation
•
HARP Enclosure Requirements for Microsoft® Windows® CE, 1998,
Microsoft Corporation.
Further information on these topics is available from the Microsoft web site.
x
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Feedback
ARM Limited welcomes feedback both on the ARM Integrator/CM940T core module
and on the documentation.
Feedback on this document
If you have any comments about this document, please send email to
errata@arm.com giving:
•
the document title
•
the document number
•
the page number(s) to which your comments refer
•
an explanation of your comments.
General suggestions for additions and improvements are also welcome.
Feedback on the ARM Integrator/CM940T
If you have any comments or suggestions about this product, please contact your
supplier giving:
•
the product name
•
an explanation of your comments.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
xi
xii
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Chapter 1
Introduction
This chapter introduces the ARM Integrator/CM940T core module. It contains the
following sections:
ARM DUI 0125A
•
About the ARM Integrator/CM940T core module on page 1-2
•
ARM Integrator/CM940T overview on page 1-4
•
Links and indicators on page 1-8
•
Test points on page 1-10
•
Precautions on page 1-11.
© Copyright ARM Limited 1999. All rights reserved.
1-1
Introduction
1.1
About the ARM Integrator/CM940T core module
The Integrator/CM940T core module provides you with the basis of a flexible
development system which can be used in a number of different ways. With power and
a simple connection to a Multi-ICE debugger, the core module provides a basic
development system. By mounting the core module onto a motherboard, you can build
a realistic emulation of the system being developed. Through-board connectors allow
up to four core modules to be stacked on one motherboard.
The core module can be used in the following ways:
•
as a standalone development system
•
mounted onto an ARM Integrator/SP development motherboard
•
mounted onto an ARM Integrator/AP development motherboard
•
integrated into a third-party development or ASIC prototyping system.
Figure 1-1 on page 1-3 shows the layout of the ARM Integrator/CM940T.
1-2
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Introduction
Core module/motherboard
connectors HDRB
Reset button
DIMM socket
SDRAM DIMM
Multi-ICE
connector
Processor
core
Power
connector
Memory controller and
system bus bridge (FPGA)
Core module/motherboard
connectors HDRA
Figure 1-1 Integrator/CM940T layout
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
1-3
Introduction
1.2
ARM Integrator/CM940T overview
The major components on the core module are as follows:
•
ARM940T microprocessor core
•
core module FPGA which implements:
— SDRAM controller
— system bus bridge
— reset controller
— interrupt controller
— status, configuration, and interrupt registers.
•
volatile memory comprising:
— up to 256MB of SDRAM (optional) via DIMM socket
— 256KB SSRAM.
•
SSRAM controller
•
clock generator
•
system bus connectors
•
Multi-ICE debug connector.
1.2.1
System architecture
Figure 1-2 illustrates the architecture of the core module.
ARM core
SSRAM
FPGA
Multi-ICE
SDRAM
System bus connectors
Figure 1-2 ARM Integrator/CM940T block diagram
1-4
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Introduction
1.2.2
Core module FPGA
The FPGA provides system control functions for the core module, enabling it to operate
as a standalone development system or attached to a motherboard. These functions are
outlined in this section and described in detail in Chapter 3 Hardware Description.
SDRAM controller
The SDRAM controller is implemented within the FPGA. This provides support for
Dual In-line Memory Modules (DIMMs) with a capacity of between 16 and 256MB.
See SDRAM controller on page 3-6.
Reset controller
The reset controller initializes the core and allows the core module to be reset from five
sources:
•
reset button
•
motherboard
•
other core modules
•
Multi-ICE
•
software.
For information about the reset controller, see Reset controller on page 3-8.
System bus bridge
The system bus bridge provides an interface between the memory bus on the core
module and the system bus on a motherboard. It allows the local processor access to
interface resources on the motherboard and to the SDRAM on other core modules. It
also allows access to the local SDRAM from the PCI bridge on the motherboard and
processors on other core modules (see System bus bridge on page 3-11).
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
1-5
Introduction
Status and configuration space
The status and configuration space contains status and configuration registers for the
core module. These provide the following information and control:
•
type of processor and whether it has a cache, MMU, or protection unit
•
the position of the core module in a multi-module stack
•
SDRAM size, address configuration, and CAS latency setup
•
core module oscillator setup
•
interrupt control for the processor debug communications channel.
The status and control registers can only be accessed by the local processor. For more
information about the status and control registers see Chapter 4 Programmer’s
Reference.
1.2.3
Volatile memory
The volatile memory system includes an SSRAM device, and a plug-in SDRAM
memory module (referred to as local SDRAM when it is on the same core module as
the processor). These areas of memory are closely coupled to the processor core to
ensure high performance. The core module uses separate memory and system buses to
avoid memory access performance being degraded by bus loading.
The SDRAM controller is implemented within the core module controller FPGA and a
separate SSRAM controller is implemented with a Programmable Logic Device (PLD).
The SDRAM can be accessed by the local processor, by processors on other core
modules, and by other system bus masters.
The SSRAM can only be accessed by the local processor.
1.2.4
Clock generator
The core module uses two on-board clocks:
•
CPU clock up to 160MHz
•
memory bus clock up to 66MHz.
These clocks are supplied by two clock generator chips. Their frequencies are selected
via the oscillator control register (CM_OSC) within the FPGA. A reference clock is
supplied to the two clock generators and to the FPGA (see Clock generators on
page 3-17). The memory bus and system bus are asynchronous. This allows each bus to
be run at the speed of its slowest device without compromising the performance of other
buses in the system.
1-6
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Introduction
1.2.5
Multi-ICE connector
The Multi-ICE connector enables JTAG hardware debugging equipment, such as
Multi-ICE, to be connected to the core module. It is possible to both drive and sense the
system-reset line (nSRST), and to drive JTAG reset (nTRST) to the core from the
Multi-ICE connector. See Multi-ICE support on page 3-21.
Note
JTAG test equipment supplied by other vendors may also be used.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
1-7
Introduction
1.3
Links and indicators
CFGLED
POWER
FPGA OK
MISC CONFIG
The core module provides one link and four surface-mounted LEDs. These are
illustrated in Figure 1-3.
Figure 1-3 Links and indicators
1.3.1
CONFIG link
The core module has only one link, marked CONFIG. This is left open during normal
operation. It is only fitted when downloading new FPGA and PLD configuration
information.
1-8
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Introduction
1.3.2
LED indicators
The functions of the four surface-mounted LEDs are summarized in Table 1-1.
Table 1-1 LED functional summary
ARM DUI 0125A
Name
Color
Function
MISC
Green
This LED is controlled via the control register (see
CM_CTRL (0x1000000C) on page 4-11).
FPGA OK
Green
This LED illuminates when the FPGA has successfully
loaded its configuration information following power-on.
POWER
Green
This LED illuminates to indicate that a 3.3V supply is
present.
CFGLED
Orange
This LED illuminates to indicate that the CONFIG link is
fitted.
© Copyright ARM Limited 1999. All rights reserved.
1-9
Introduction
1.4
Test points
The core module provides two ground and five signal test points as an aid to debug.
These are illustrated in Figure 1-4.
TP6
TP7
TP1
Voltage
regulator
TP3
TP5
TP4
TP2
Figure 1-4 Test points
The functions of the test points are summarized in Table 1-2.
Table 1-2 Test point functions
1-10
Test point
Name
Function
TP1
GND
Ground
TP2
GND
Ground
TP3
FCLKOUT
Clock output from the ARM940T microprocessor core
TP4
LBCLK
Local memory bus clock
TP5
Core clock
Clock supplied to the ARM940T microprocessor core
TP6
VDD940T
Output from voltage regulator
TP7
ADJ
ADJ pin of voltage regulator
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Introduction
1.5
Precautions
This section contains safety information and advice on how to avoid damage to the core
module.
1.5.1
Ensuring safety
Warning
To avoid a safety hazard, only Safety Extra Low Voltage (SELV) equipment should be
connected to the JTAG interface.
1.5.2
Preventing damage
The core module is intended for use within a laboratory or engineering development
environment. It is supplied without an enclosure which leaves the board sensitive to
electrostatic discharges and allows electromagnetic emissions.
Caution
To avoid damage to the board you should observe the following precautions.
•
•
•
•
•
ARM DUI 0125A
Never subject the board to high electrostatic potentials.
Always wear a grounding strap when handling the board.
Only hold the board by the edges.
Avoid touching the component pins or any other metallic element.
Do not use the board near equipment which could be:
— sensitive to electromagnetic emissions (such as medical equipment)
— a transmitter of electromagnetic emissions.
© Copyright ARM Limited 1999. All rights reserved.
1-11
Introduction
1-12
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Chapter 2
Getting Started
This chapter describes how to set up and prepare the ARM Integrator/CM940T core
module for use. It contains the following sections:
ARM DUI 0125A
•
Setting up a standalone ARM Integrator/CM940T on page 2-2
•
Attaching the ARM Integrator/CM940T to a motherboard on page 2-5.
© Copyright ARM Limited 1999. All rights reserved.
2-1
Getting Started
2.1
Setting up a standalone ARM Integrator/CM940T
To set up the core module as a standalone development system:
2.1.1
1.
Optionally, fit an SDRAM DIMM.
2.
Supply power.
3.
Connect Multi-ICE.
Fitting an SDRAM DIMM
You should fit the following type of SDRAM module:
•
PC66- or PC100-compliant 168pin DIMM
•
unbuffered
•
16MB, 32MB, 64MB, 128MB or 256MB.
To install an SDRAM DIMM:
1.
Ensure that the core module is powered down.
2.
Open the SDRAM retaining latches outwards.
3.
Press the SDRAM module into the edge connector until the retaining latches
click into place.
Note
The DIMM edge connector has polarizing notches to ensure that it is correctly oriented
in the socket.
2.1.2
Using the core module without SDRAM
The core module can be operated without SDRAM because it has 256KB of SSRAM
permanently fitted. However, in order to operate the core module with ARM debuggers,
you must change the internal variable $top_of_memory from the default setting of
0x00080000 (= 512KB) to 0x00040000 (= 256KB) before running programs that are
linked with the standard libraries.
For further information about ARM debugger internal variables, refer to the Software
Development Toolkit Reference Guide.
2-2
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Getting Started
2.1.3
Supplying power
5V
3.3V
GND
GND 3V3 5V
When using the core module as a standalone development system, you should connect
a bench power supply with 3.3V and 5V outputs to the power connector, as illustrated
in Figure 2-1.
Figure 2-1 Power connector
Note
This power connection is not required when the core module is fitted to a motherboard.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
2-3
Getting Started
2.1.4
Connecting Multi-ICE
When you are using the core module as a standalone system, Multi-ICE debugging
equipment can be used to download programs. The Multi-ICE setup for a standalone
core module is shown in Figure 2-2.
Multi-ICE
server/debugger
Parallel
cable
Multi
ICE
Multi-ICE unit
Power supply
Core module
Figure 2-2 Multi-ICE connection to a core module
Caution
Because the core module does not provide non-volatile memory, programs are lost
when the power is removed.
Multi-ICE can also be used when a core module is attached to a motherboard. If more
than one core module is attached, then the Multi-ICE unit must be connected to the
module at the top of the stack. The Multi-ICE server and the debugger can be on one
computer or on two networked computers.
2-4
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Getting Started
2.2
Attaching the ARM Integrator/CM940T to a motherboard
Attach the core module onto a motherboard (for example, the ARM Integrator/SP) by
engaging the connectors HDRA and HDRB on the bottom of the core module with the
corresponding connectors on the top of the motherboard. The lower side of the core
module has sockets and the upper side of the core module has plugs to allow core
modules to be mounted on top of one another. A maximum of four core modules can be
stacked on a motherboard.
Figure 2-3 illustrates an example development system with four core modules attached
to an ARM Integrator/SP motherboard.
Module 3
Module 2
Module 1
Module 0
Motherboard
Figure 2-3 Assembled Integrator system
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
2-5
Getting Started
2.2.1
Core module ID
The ID of the core module is configured automatically by the connectors (there are no
links to set) and depends on its position in the stack:
•
core module 0 is installed first
•
core module 1 is installed next, and cannot be fitted without core module 0
•
core module 2 is installed next, and cannot be fitted without core module 1
•
core module 3 is installed next, and cannot be fitted without core module 2.
The ID of the core module also defines the ID of the microprocessor it carries and the
system bus address of its SDRAM. The position of a core module in the stack can be
read from the CM_STAT register. See CM_STAT (0x10000010) on page 4-12.
2.2.2
Powering the assembled Integrator development system
Power the assembled Integrator development system by:
•
connecting a bench power supply to the motherboard
•
installing the motherboard in a card cage or an ATX-type PC case, depending on
type.
For further information, refer to the user guide for the motherboard you are using.
2-6
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Chapter 3
Hardware Description
This chapter describes the on-board hardware. It contains the following sections:
•
ARM940T microprocessor core on page 3-2
•
SSRAM controller on page 3-3
•
Core module FPGA on page 3-4
•
SDRAM controller on page 3-6
•
Reset controller on page 3-8
•
System bus bridge on page 3-11
•
Clock generators on page 3-17
•
Multi-ICE support on page 3-21.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
3-1
Hardware Description
3.1
ARM940T microprocessor core
The ARM940T cached processor macrocell is a member of the ARM9 Thumb family
of high-performance 32-bit system-on-a-chip processors. It provides the following:
•
ARM9TDMI RISC integer CPU
•
4KB instruction and data caches
•
write buffer
•
protection unit
•
AMBA ASB bus interface.
The ARM940T processor employs a Harvard cache architecture, and so has separate
4KB instruction and 4KB data caches. Each cache has a 4-word line length.
The protection unit allows eight regions of memory to be defined, each with individual
cache and write buffer configurations and access permissions.
The cache system is software-configurable to provide highest average performance or
to meet the needs of real-time systems. Software configurable options include:
•
random or round-robin cache line replacement algorithm
•
write-through or writeback cache operation
•
cache locking with granularity 1/64 th of cache size.
The caches and write buffers improve CPU performance and minimize accesses to
off-chip memory, thus reducing overall system power consumption. The ARM940T
includes support for coprocessors, allowing a floating point unit or other
application-specific hardware acceleration to be added.
The ARM9TDMI core executes both the 32-bit ARM and 16-bit Thumb instruction
sets, allowing you to trade between high performance and high code density. It is
binary-compatible with ARM7TDMI, ARM10TDMI, and StrongARM processors, and
is supported by a wide range of tools, operating systems, and application software.
The ARM940T also features a TrackingICE mode which allows an approach similar to
a conventional ICE mode of operation.
For more information about the ARM940T, refer to the ARM940T Technical Reference
Manual.
3-2
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Hardware Description
3.2
SSRAM controller
The SSRAM controller is implemented in a Xilinx 9572 PLD which enables the
SSRAM to achieve single-cycle operation. In addition to controlling accesses to the
SSRAM, the controller generates the processor response signals (BWAIT, BERROR,
BLAST) for all accesses to:
•
SSRAM
•
SDRAM
•
status and configuration register space
•
system bus bridge.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
3-3
Hardware Description
3.3
Core module FPGA
The core module FPGA contains five main functional blocks:
•
SDRAM controller on page 3-6
•
Reset controller on page 3-8
•
System bus bridge on page 3-11
•
Core module registers on page 4-7
•
Debug interrupt controller, see Debug communications interrupts on page 3-27.
The FPGA provides sufficient functionality for the core module to operate as a
standalone development system, although with limited capabilities. System bus
arbitration, system interrupt control, and input/output resources are provided by the
system controller FPGA on the motherboard. See the user guide for your motherboard
for further information.
Figure 3-1 illustrates the function of the core module FPGA and shows how it connects
to the other devices in the system.
SSRAM
Clock
generator
Status/
control
registers
Reset
controller
Memory bus
SDRAM
controller
SSRAM
controller
(PLD)
ARM core
SDRAM
System bus
bridge
FPGA
System bus
Multi-ICE
System bus connectors
HDRA/HDRB
Figure 3-1 FPGA functional diagram
3-4
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Hardware Description
At power-up the FPGA loads its configuration data from a flash memory device.
Parallel data from the flash is serialized by the Programmable Logic Device (PLD) into
the configuration inputs of the FPGA. Figure 3-2 shows the FPGA configuration
mechanism.
A[18:0]
D[7:0]
DIN
FPGA
CCLK
DONE
PLD
OE
WE
FPGA
configuration
ROM
(flash)
CS
Multi-ICE
Figure 3-2 FPGA configuration
Multi-ICE can be used to reprogram the PLD, FPGA, and flash when the core module
is placed in configuration mode. See Multi-ICE support on page 3-21.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
3-5
Hardware Description
3.4
SDRAM controller
The core module provides support for a single 16, 32, 64, 128, or 256MB SDRAM
DIMM.
3.4.1
SDRAM operating mode
The operating mode of the SDRAM devices is controlled with the mode set register
within each SDRAM. These registers are set immediately after power-up to specify:
•
a burst size of four for both reads and writes
•
Column Address Strobe (CAS) latency of 2 cycles.
The CAS latency and memory size can be reprogrammed via the SDRAM control
register (CM_SDRAM) at address 0x10000020. See CM_SDRAM (0x10000020) on
page 4-14.
Note
Before the SDRAM is used it is necessary to read the SPD memory and program the
CM_SDRAM register with the parameters indicated in Table 4-8 on page 4-14. If these
values are not correctly set then SDRAM accesses may be slow or unreliable.
3.4.2
Access arbitration
The SDRAM controller provides two ports to support reads and writes by the local
processor core and by masters on the motherboard. The SDRAM controller uses an
alternating priority scheme to ensure that the processor core and motherboard have
equal access (see System bus bridge on page 3-11).
3.4.3
Serial presence detect
JEDEC-compliant SDRAM DIMMs incorporate a Serial Presence Detect (SPD)
feature. This comprises a 2048-bit serial EEPROM located on the DIMM with the first
128 bytes programmed by the DIMM manufacturer to identify the following:
•
module type
•
memory organization
•
timing parameters.
The EEPROM clock (SCL) operates at 93.75kHz (24MHz divided by 256). The transfer
rate for read accesses to the EEPROM is 100kbit/s maximum. The data is read out
serially 8 bits at a time, preceded by a start bit and followed by a stop bit. This makes
reading the EEPROM a very slow process because it takes approximately 27ms to read
all 256 bytes. However, during power-up the contents of the EEPROM are copied into
3-6
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Hardware Description
a 64 x 32-bit area of memory (CM_SPD) within the SDRAM controller. The SPD flag
is set in the SDRAM control register (CM_SDRAM) when the SPD data is available.
This copy can be randomly accessed at 0x10000100 to 0x100001FC (see CM_SPD
(0x10000100 to 0x100001FC) on page 4-16).
Write accesses to the SPD EEPROM are not supported.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
3-7
Hardware Description
3.5
Reset controller
The core module FPGA incorporates a reset controller which enables the core module
to be reset as a standalone unit or as part of an Integrator development system. The core
module can be reset from five sources:
•
reset button
•
motherboard
•
other core modules
•
Multi-ICE
•
software.
Figure 3-3 shows the architecture of the reset controller.
nSYSRST
nMBDET
Core
SWRST
0
1
Sync
PBRST
nDONE
Motherboard
and other
core modules
BnRES_M
nSRST
Reset
control
Multi-ICE
FPGA
Figure 3-3 Core module reset controller
3-8
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Hardware Description
3.5.1
Reset signals
Table 3-1 describes the external reset signals.
Table 3-1 Reset signal descriptions
Name
Description
Type
Function
BnRES_M
Processor reset
Output
The BnRES_M signal is used to reset the processor core. It is
generated from nSRST LOW when the core module is used
standalone, or nSYSRST LOW when the core module is
attached to a motherboard.
It is asserted as soon as the appropriate input becomes active.
It is deasserted synchronously from the falling edge of the
processor bus clock.
nDONE
FPGA configured
Input
The nDONE signal is an inversion of the open collector
signal FPGADONE which is generated by all FPGAs when
they have completed their configuration. The FPGADONE
signal is routed round the system through the HDRB
connectors to the inputs of all other FPGAs in the system. The
signal nSRST is held asserted until nDONE is driven LOW.
nMBDET
Motherboard detect
Input
The nMBDET signal is pulled LOW when the core module is
attached to a motherboard and HIGH when the core module is
used standalone.
When MBDET is LOW, nSYSRST is used to generate the
BnRES_M signal.
When nMBDET is HIGH, nSRST is used to generate the
BnRES_M signal.
PBRST
Push-button reset
Input
The PBRST signal is generated by pressing the reset button.
nSRST
System reset
Bidirectional
The nSRST open collector output signal is driven LOW by
the core module FPGA when the signal PBRST or software
reset (SWRST) is asserted.
As an input, nSRST can be driven LOW by Multi-ICE.
If there is no motherboard present, the nSRST signal is
synchronized to the processor bus clock to generate the
BnRES-M signal.
nSYSRST
System reset
Input
The nSYSRST signal is generated by the system controller
FPGA on the motherboard. It is used to generate the
BnRES_M signal when the core module is attached to a
motherboard. It is selected by the motherboard detect signal
(nMBDET).
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
3-9
Hardware Description
3.5.2
Software resets
The core module FPGA provides a software reset which can be triggered by writing to
the reset bit in the CM_CTRL register. This generates the internal reset signal SWRST
which generates nSRST and resets the whole system (see CM_CTRL (0x1000000C) on
page 4-11).
3-10
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Hardware Description
3.6
System bus bridge
The system bus bridge provides an asynchronous bus interface between the local system
bus and system bus connecting the motherboard and other modules.
Inter-module accesses are supported by two 16 x 74-bit FIFOs. Each of the 16 entries
in the FIFOs contains:
•
32-bit data used for write transfers
•
32-bit address used for reads and writes
•
10-bit transaction control used for reads and writes.
3.6.1
Processor accesses to the system bus
The first FIFO supports read and write accesses by the local processor to the system bus,
which extends onto the motherboard and other modules.
Processor writes
The data routing for processor writes to the system bus is illustrated in Figure 3-4.
Processor
core
SDRAM
controller
SDRAM
FIFO
FIFO
Motherboard
Figure 3-4 Processor writes to the system bus
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
3-11
Hardware Description
Write transactions from the processor to the system bus normally complete on the local
memory bus in a single cycle. The data, address, and control information associated
with the transfer are posted into FIFO, and the transfer on the system bus occurs some
time later when that bus is available. This means that system bus error responses to
write transfers are not reported back to the processor as data aborts. If the FIFO is full,
the processor receives a wait response until space becomes available.
Processor reads
The data routing for processor reads from the system bus is illustrated in Figure 3-5.
Processor
core
SDRAM
controller
SDRAM
FIFO
FIFO
Motherboard
Figure 3-5 Processor reads from the system bus
For reads from the system bus, the address and control information also pass through
the FIFO. The returned data from the system bus bypasses the FIFO.
The order of processor transactions is preserved on the system bus. Any previously
posted writes are drained from the FIFO (that is, completed on the system bus) before
the read transfer is performed. The processor receives a wait response until the read
transfer has completed on the system bus, when it receives the data and any associated
bus error response from the system bus. For information about SDRAM addresses, see
SDRAM accesses on page 4-4.
3-12
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Hardware Description
3.6.2
Motherboard accesses to SDRAM
The second FIFO supports read and write accesses by system bus masters on the
motherboard and other core modules to the local core module memory.
System bus writes
The data routing for system bus writes to SDRAM is illustrated in Figure 3-6.
Processor
core
SDRAM
controller
SDRAM
FIFO
FIFO
Motherboard
Figure 3-6 System bus writes to SDRAM
Write transactions from the system bus to the SDRAM normally complete in a single
cycle on the system bus. The data, address, and control information associated with the
transfer are posted into the FIFO, and the transfer into the SDRAM completes when the
SDRAM is available. If the FIFO is full, then the system bus master receives a retract
response indicating that the arbiter may grant the bus to another master and that this
transaction must be retried later.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
3-13
Hardware Description
System bus reads
The data routing for system bus reads from SDRAM is illustrated in Figure 3-7.
Processor
core
SDRAM
controller
SDRAM
FIFO
FIFO
Motherboard
Figure 3-7 System bus reads from SDRAM
For system bus reads, the address and control information also pass through the FIFO,
but the returned data from the SDRAM bypasses the FIFO.
The order of transactions on the system bus and the memory bus is preserved. Any
previously posted write transactions are drained from the FIFO (that is, writes to
SDRAM are completed) before the read transfer is performed.
3.6.3
Multiprocessor
The two FIFOs operate independently, as described above, and can be accessed at the
same time. This makes it possible for a local processor to read local SDRAM via the
system bus (through both FIFOs). This feature can be used to support multiprocessor
systems that share data in SDRAM because the processors can all access the same
DRAM locations at the same addresses.
3-14
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Hardware Description
3.6.4
System bus signal routing
The core module is mounted onto a motherboard via the connectors HDRA and HDRB.
As well as carrying all signal connections between the boards, these provide mechanical
mounting (see Attaching the ARM Integrator/CM920T to a motherboard on page 2-5).
HDRA
The signals on the HDRA connectors are tracked between the socket on the underside
and the plug on the top so that pin 1 connects to pin 1, pin 2 to pin 2 and so on. That is,
the signals are routed straight through.
HDRB
A number of signals on the HDRB connectors are rotated in groups of four between the
connectors on the bottom and top of each module. This ensures that each processor (or
other bus master device) on a module connects to the correct signals according to
whether it is bus master 0, 1, 2, or 3. The ID for the bus master on a module is
determined by the position of the module in the stack.
This signal rotation scheme is illustrated in Figure 3-8.
D
C
B
A
C
B
A
D
C
B
A
D
B
A
D
C
B
A
D
C
A
D
C
B
A
D
C
B
D
C
B
A
D
C
B
A
Module 3
Module 2
To on-board
devices
Module 1
Module 0
Motherboard
Figure 3-8 Signal rotation on HDRB
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
3-15
Hardware Description
The example in Figure 3-8 illustrates how a group of four signals (labelled A, B, C, and
D) are routed through a group of four connector pins up through the stack. It highlights
how signal C is rotated as it passes up through the stack and only utilized on module 2.
All four signals are rotated and utilized in a similar way, as follows:
•
signal A on core module 0
•
signal B on core module 1
•
signal C used on core module 2
•
signal D used on core module 3.
For details of the signals on the HDRB connectors, see HDRB on page A-4.
Note
The JTAG signals are discussed in Multi-ICE support on page 3-21.
3.6.5
Bus operating modes
The bus operating modes are programmed by writing to coprocessor 15 register 1 within
the ARM940T microprocessor core.
The Integrator system supports:
•
asynchronous and FastBus clocking
•
little-endian addressing.
The Integrator system does not support:
•
synchronous clocking
•
big-endian addressing.
For details of how to set the bus operating parameters, refer to the ARM940T Technical
Reference Manual.
3-16
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Hardware Description
3.7
Clock generators
The core module provides its own clock generators and operates asynchronously with
the motherboard. The clock generator provides two programmable clocks:
•
processor core clock CORECLK
•
processor local memory bus clocks LCLK and nLCLK.
In addition, a fixed-frequency reference clock REFCLK is supplied to the FPGA.
These clocks are supplied by two MicroClock ICS525 devices and by the SSRAM
controller PLD, as illustrated in Figure 3-9.
FPGA
CM_OSC register
24MHz
crystal
ICS525
(U6)
ICS525
(U7)
2XCLK
REFCLK
CORECLK
LCLK
SSRAM controller
(PLD)
nLCLK
Figure 3-9 Core module clock generator
The ICS525s are supplied with a reference clock signal from a 24MHz crystal
oscillator. The 2XCLK output from the first ICS525 (U6) is supplied to the PLD and
divided by two to produce the signals LCLK and nLCLK. The output from U7
provides the CORECLK signal. The reference output from U6 supplies the reference
input to U7 and the reference output from U7 supplies the FPGA reference clock.
The output frequencies from the ICS525s are configured using divider input pins to
produce a wide range of frequencies.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
3-17
Hardware Description
3.7.1
Processor core clock (CORECLK)
The frequency of CORECLK is controllable in 1MHz steps in the range 12MHz to
160MHz. This is achieved by setting the Voltage Controlled Oscillator (VCO) divider
and output divider for the CORECLK generator via the CM_OSC register. The VCO
divider is controlled by the C_VDW bits and output divider is controlled by the C_OD
bits. The reference divider value is fixed.
Table 3-2 shows the values placed on the divider input pins and how the clock speeds
are derived. The bits marked:
•
C are programmable in the CM_OSC register
•
1 are tied HIGH
•
0 are tied LOW.
Table 3-2 CORECLK divider values
C_RDW R[6:0]
0
0
1
0
1
22 (fixed value)
C_VDW V[8:0]
1
0
0
C
C
C
C
C
C_OD S[2:0]
C
C
4 – 152 (<4 and >152 not allowed)
C
C
C
C
2-10
12 – 160MHz in 1MHz steps
The frequency of CORECLK can be derived from the formula:
freq = 2*((C_VDW+ 8)/C_OD)
where:
C_VDW is the VCO divider word for the core clock.
C_OD is the output divider for the core clock.
For details about programming C_VDW and C_OD, see CM_OSC (0x10000008) on
page 4-9.
Note
Values for C_VDW and C_OD can be calculated using the ICS525 calculator on the
Microclock website.
The CORECLK is buffered with a PI49FCT3805 to convert the Phase-Locked Loop
(PLL) output to 3.3V signal level. The clock is series terminated with a 33Ω resistor and
then drives a single load on the microprocessor core.
3-18
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Hardware Description
3.7.2
Processor bus clocks (LCLK and nLCLK)
The frequency of the processor bus clocks LCLK and nLCLK is determined by the
frequency of 2XCLK. The clock signal 2XCLK is divided by 2 by the SSRAM
controller PLD to produce LCLK and nLCLK.
The frequency of LCLK is controllable in 0.5MHz steps in the range 6MHz to 66MHz.
This is achieved by programming the VCO and output divider bits for the 2XCLK
generator in the CM_OSC register. The VCO divider is controlled by the L_VDW bits
and the output divider is controlled by the L_OD bits.The reference divider is fixed.
The maximum speed of 2XCLK is limited by the speed of the SSRAM PLD.
Table 3-3 shows the values placed on the divider input pins and how the clock speeds
are obtained. The bits marked:
•
L are programmable in the CM_OSC register
•
1 are tied HIGH
•
0 are tied LOW.
Table 3-3 2XCLK divider values
L_RDW R[6:0]
0
0
1
0
1
L_VDW V[8:0]
1
0
0
L
22 (fixed value)
L
L
L
L
L_OD S[2:0]
L
L
4 – 124 (<4 and >124 not allowed)
L
L
L
L
2-10
12 – 132MHz in 1MHz steps (for 2XCLK)
The frequency of LCLK can be derived from the formula:
freq = (L_VDW+ 8)/L_OD
where:
L_VDW is the VCO divider word for the processor bus clock.
L_OD is the output divider for the processor bus clock.
Note
Values for L_VDW and L_OD can be calculated using the ICS525 calculator on the
Microclock website.
For details about programming L_VDW and L_OD, see CM_OSC (0x10000008) on
page 4-9.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
3-19
Hardware Description
The LCLK clock signal is buffered by a 5-output low-skew buffer PI49FCT3805 to
drive five loads. These are:
•
SDRAM_CLK[3:0]
•
SSRAM_CLK.
The nLCLK clock signal is a phase-aligned inversion of the LCLK signal. It is
buffered by a 5-output low-skew buffer PI49FCT3805 to four loads. These are:
•
ARM_BCLK_M
•
PLD_BCLK_M
•
FPGA_BCLK_M
•
LA_BCLK_M.
All clocks are series terminated with 33Ω resistors placed as close to the source as
possible.
3.7.3
FPGA reference clock (REFCLK)
The REFCLK signal is used by the FPGA to generate the SDRAM refresh clock and
SPD EEPROM clock. This is a fixed-frequency clock of 24MHz which is output from
the reference pin of the second ICS525 chip U7.
3-20
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Hardware Description
3.8
Multi-ICE support
The core module provides support for debug using JTAG. It provides a Multi-ICE
connector and JTAG scan paths around the development system. Figure 3-10 shows the
Multi-ICE connector and the CONFIG link.
Multi-ICE connector
CONFIG link
CFGLED
Figure 3-10 JTAG connector, CONFIG link, and LED
The CONFIG link is used to enable in-circuit programming of the FPGA and PLDs
using Multi-ICE (see Debugging modes on page 3-23).
The Multi-ICE connector provides a set of JTAG signals allowing third-party JTAG
debugging equipment to be used (see JTAG signals on page 3-24). If you are debugging
a development system with multiple core modules, connect the Multi-ICE hardware to
the top core module.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
3-21
Hardware Description
3.8.1
JTAG scan path
Core module
Multi-ICE
Figure 3-11 shows a simplified diagram of the scan path.
TDO
TDI
TDI
Processor
core
HDRB
HDRB
TDI
TDO
nMBDET
Core module
TDI
Processor
core
HDRB
HDRB
Motherboard
Figure 3-11 JTAG scan path (simplified)
When the core module is used as a standalone development system, the JTAG scan path
is routed through the processor core and back to the Multi-ICE connector.
When the core module is attached to a motherboard, either directly or with other core
modules, the TDI signal from the top core module is routed down through the HDRB
connectors to the motherboard. The path is routed back up the stack through the
processor core on each core module, before being returned to the Multi-ICE connector.
The motherboard detect signal nMBDET signal is used to control the routing for a
standalone or an attached core module.
The PLDs and FPGAs are included in the scan chain when the core module is in
configuration mode.
3-22
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Hardware Description
3.8.2
Debugging modes
The core module is capable of operating in two modes:
•
normal debug mode
•
configuration mode.
Normal debug mode
During normal operation and software development, the core module operates in debug
mode. The debug mode is selected by default (when a jumper is not fitted at the
CONFIG link, see Figure 3-10 on page 3-21). In this mode, the processor core and
debuggable devices on other modules are accessible on the scan chain, as shown in
Figure 3-11 on page 3-22.
Configuration mode
In configuration mode the debuggable devices are still accessible and, in addition, all
FPGAs and PLDs in the system are added into the scan chain. This allows the board to
be configured or upgraded in the field using Multi-ICE or other JTAG debugging
equipment.
To select configuration mode, fit a jumper to the CONFIG link on the core module at
the top of the stack (see Figure 3-10 on page 3-21). This has the effect of pulling the
nCFGEN signal LOW which illuminates the CFG LED (yellow) on each module in the
stack and reroutes the JTAG scan path. The LED provides a warning that the
development system is in the configuration mode.
Note
Configuration mode is guaranteed for a single core module attached to a motherboard
but may be unreliable if more than one core module is attached. The larger loads on the
TCK and TMS lines may cause unreliable operation.
After configuration or code updates you must:
ARM DUI 0125A
1.
Remove the CONFIG link.
2.
Power cycle the development system.
© Copyright ARM Limited 1999. All rights reserved.
3-23
Hardware Description
The configuration mode allows FPGA and PLD code to be updated as follows:
3.8.3
•
The FPGAs are volatile, but load their configuration from flash memory. Flash
memory, which itself does not have a JTAG port, can be programmed by loading
designs into the FPGAs and PLDs which handle the transfer of data to the flash
using JTAG.
•
The PLDs are non-volatile devices which can be programmed directly by JTAG.
JTAG signals
Figure 3-12 shows the pinout of the Multi-ICE connector and Table 3-4 on page 3-25
provides a description of the JTAG signals.
3V3
nTRST
TDI
TMS
TCK
RTCK
TDO
nSRST
DBGRQ
DBGACK
1 2
3V3
GND
GND
GND
GND
GND
GND
GND
GND
GND
19 20
Figure 3-12 Multi-ICE connector pinout
Note
In the description in Table 3-4 on page 3-25, the term JTAG equipment refers to any
hardware that can drive the JTAG signals to devices in the scan chain. In most cases this
will be Multi-ICE, although hardware from third-party suppliers can also be used to
debug ARM processors.
3-24
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Hardware Description
Table 3-4 JTAG signal description
Name
Description
Function
DBGRQ
Debug request
(from JTAG equipment)
DBGRQ is a request for the processor core to enter the debug
state. It is provided for compatibility with third-party JTAG
equipment.
DBGACK
Debug acknowledge
(to JTAG equipment)
DBGACK indicates to the debugger that the processor core has
entered debug mode. It is provided for compatibility with
third-party JTAG equipment.
DONE
FPGA configured
DONE is an open-collector signal which indicates when FPGA
configuration is complete. Although this signal is not a JTAG
signal, it does effect nSRST. The DONE signal is routed between
all FPGAs in the system through the HDRB connectors. The
master reset controller on the motherboard senses this signal and
holds all the boards in reset (by driving nSRST LOW) until all
FPGAs are configured.
nCFGEN
Configuration enable
(from jumper on module at the
top of the stack)
nCFGEN is an active LOW signal used to put the boards into
configuration mode. In configuration mode all FPGAs and PLDs
are connected to the scan chain so that they can be configured by
the JTAG equipment.
nRTCKEN
Return TCK enable (from core
module to motherboard)
nRTCKEN is an active LOW signal driven by any core module
that requires RTCK to be routed back to the JTAG equipment. If
nRTCKEN is HIGH, the motherboard drives RTCK LOW. If
nRTCKEN is LOW, the motherboard drives the TCK signal
back up the stack to the JTAG equipment.
nSRST
System reset (bidirectional)
nSRST is an active LOW open-collector signal which can be
driven by the JTAG equipment to reset the target board. Some
JTAG equipment senses this line to determine when a board has
been reset by the user.
The open collector nRST reset signal may be driven LOW by the
reset controller on the core module to cause the motherboard to
reset the whole system by driving nSYSRST LOW.
This is also used in configuration mode to control the
initialization pin (nINIT) on the FPGAs.
Though not a JTAG signal, nSRST is described because it can be
controlled by JTAG equipment.
nTRST
Test reset (from JTAG
equipment)
This active low open-collector is used to reset the JTAG port and
the associated debug circuitry on the ARM940T processor. It is
asserted at power-up by each module, and can be driven by the
JTAG equipment. This signal is also used in configuration mode
to control the programming pin (nPROG) on FPGAs.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
3-25
Hardware Description
Table 3-4 JTAG signal description (continued)
Name
Description
Function
RTCK
Return TCK
(to JTAG equipment)
Some devices sample TCK (for example a synthesizable core
with only one clock), and this has the effect of delaying the time
at which a component actually captures data. RTCK is a
mechanism for returning the sampled clock to the JTAG
equipment, so that the clock is not advanced until the
synchronizing device captured the data. In adaptive clocking
mode, Multi-ICE is required to detect an edge on RTCK before
changing TCK. In a multiple device JTAG chain, the RTCK
output from a component connects to the TCK input of the
down-stream device. The RTCK signal on the module
connectors HDRB returns TCK to the JTAG equipment. If there
are no synchronizing components in the scan chain then it is
unnecessary to use the RTCK signal and it is connected to
ground on the motherboard.
TCK
Test clock
(from JTAG equipment)
TCK synchronizes all JTAG transactions. TCK connects to all
JTAG components in the scan chain. Series termination resistors
are used to reduce reflections and maintain good signal integrity.
TCK flows down the stack of modules and connects to each
JTAG component. However, if there is a device in the scan chain
that synchronizes TCK to some other clock, then all down-stream
devices are connected to the RTCK signal on that component
(see RTCK).
TDI
Test data in
(from JTAG equipment)
TDI goes down the stack of modules to the motherboard and then
back up the stack, labelled TDO, connecting to each component
in the scan chain.
TDO
Test data out
(to JTAG equipment)
TDO is the return path of the data input signal TDI. The module
connectors HDRB have two pins labelled TDI and TDO. TDI
refers to data flowing down the stack and TDO to data flowing up
the stack. The JTAG components are connected in the return path
so that the length of track driven by the last component in the
chain is kept as short as possible.
TMS
Test mode select
(from JTAG equipment)
TMS controls transitions in the tap controller state machine.
TMS connects to all JTAG components in the scan chain as the
signal flows down the module stack.
3-26
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Hardware Description
3.8.4
Debug communications interrupts
The ARM940T processor core incorporates EmbeddedICE hardware and provides a
debug communications data register which is used to pass data between the processor
and JTAG equipment. The processor accesses this register as a normal 32-bit read/write
register and the JTAG equipment reads and writes the register using the scan chain. For
a description of the debug communications channel, see the ARM940T Technical
Reference Manual.
Interrupts can be used to signal when data has been written into one side of the register
and is available for reading from the other side. These interrupts are supported by the
interrupt controller within the core module FPGA and can be enabled and cleared by
accessing the interrupt registers (see Interrupt registers on page 4-19).
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
3-27
Hardware Description
3-28
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Chapter 4
Programmer’s Reference
This chapter describes the memory map and the status and control registers. It contains
the following sections:
•
Memory organization on page 4-2
•
Exception vector mapping on page 4-6
•
Core module registers on page 4-7
•
Interrupt registers on page 4-19.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
4-1
Programmer’s Reference
4.1
Memory organization
This section describes the memory map. For a standalone core module, the memory
map is limited to local SSRAM, SDRAM, and core module registers. For the full
memory map of an Integrator development system, which includes a motherboard, you
should refer to the user guide for the motherboard.
4.1.1
Core module memory map
The core module has a fixed memory map which maintains compatibility with other
ARM modules and Integrator systems. Table 4-1 shows the memory map.
Table 4-1 ARM Integrator/CM940T memory map
nMBDET
REMAP
Address range
Region size
Description
0
0
0x00000000 to 0x0003FFFF
256KB
Boot ROM (on motherboard)
0
1
0x00000000 to 0x0003FFFF
256KB
SSRAM
1
X
0x00000000 to 0x0003FFFF
256KB
SSRAM
X
X
0x00040000 to 0x0FFFFFFF
256MB
Local SDRAM
X
X
0x10000000 to 0x10FFFFFF
16MB
Core module registers
0
X
0x11000000 to 0xFFFFFFFF
4GB to 272MB
System bus address space
1
X
0x11000000 to 0xFFFFFFFF
4GB to 272MB
Abort
4.1.2
Boot ROM and SSRAM accesses
The boot ROM on the motherboard and the SSRAM on the core module share the same
location within the Integrator memory map. Accesses to either the boot ROM or
SSRAM are controlled by the REMAP bit and the motherboard detect signal
(nMBDET) from the motherboard, as shown in Table 4-1 on page 4-2.
Remap
The REMAP bit only has effect if the core module is attached to a motherboard
(nMBDET=0). It is controlled by bit 2 of the CM_CTRL register at 0x1000000C and
functions as follows:
4-2
REMAP=0
As it is after a reset. The Boot ROM on the motherboard appears in the
address range 0x0 to 0x3FFFF.
REMAP=1
The SSRAM appears in the 0x0 to 0x3FFFF address range.
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Programmer’s Reference
Motherboard detect
The nMBDET signal operates as follows:
nMBDET=0 The core module is attached to a motherboard, and accesses in the
address range 0x0 to 0x3FFFF to the boot ROM or SSRAM are
controlled by the REMAP bit.
nMBDET=1 The core module is not attached, and accesses in the address range 0x0 to
0x3FFFF are routed to the SSRAM.
Note
The SSRAM is local, which means that it can only be read by the processor on the same
core module. It provides fast local memory for the local processor and cannot be
accessed by other system bus masters.
4GB
Abort
Motherboard
Motherboard
CM registers
CM registers
CM registers
SDRAM
SDRAM
SDRAM
SSRAM
Boot ROM
SSRAM
Standalone
Attached
(after reset)
Attached
(after remap)
272MB
256MB
256KB
Figure 4-1 Effect of remap and motherboard detect
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
4-3
Programmer’s Reference
4.1.3
SDRAM accesses
The Integrator memory map provides a 256MB address space for SDRAM. When a
smaller sized SDRAM DIMM is fitted, it is mapped repeatedly to fill the 256MB space.
For example, a 64MB DIMM appears four times, as shown in Figure 4-2.
0x0FFFFFFF
64MB
Local SDRAM
(repeat image)
64MB
Local SDRAM
(repeat image)
64MB
Local SDRAM
(repeat image)
64MB
Local SDRAM
256KB
SSRAM
0x0003FFFF
Figure 4-2 SDRAM repeat mapping for a 64MB DIMM
Local SDRAM
The local processor can access the local SDRAM (that is, the SDRAM on the same core
module) at 0x00000000 to 0x0FFFFFFF in the core module address space. However,
the lowest 256KB (0x00000000 to 0x0003FFFF) is hidden by the SSRAM or boot
ROM, depending upon whether the core module is attached to a motherboard and upon
the state of the REMAP bit.
The SDRAM cannot be accessed within this address space, although it can be accessed
at one of its repeat images or at its alias location. In the case of a 256MB DIMM which
fills the local SDRAM space, the first 256KB can only be accessed at the alias location
(see System bus accesses to SDRAM below).
4-4
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Programmer’s Reference
System bus accesses to SDRAM
If the core module is mounted on a motherboard, the SDRAM is mapped to appear at
the aliased module memory region of the combined Integrator system bus memory map.
The SDRAM can be accessed by all bus masters at its alias location, and accessed by
the local processor at both its local and alias locations.
The system bus address for a core module is automatically controlled by its position in
the stack (see Core module ID on page 2-6). Figure 4-3 shows the local and alias
address of the SDRAM on four core modules.
Local address
System bus address
0x0FFFFFFF
0xBFFFFFFF
SDRAM
core module 3
Module 3
0xB0000000
0x00000000
0xAFFFFFFF
0x0FFFFFFF
SDRAM
core module 2
Module 2
0xA0000000
0x00000000
0x9FFFFFFF
0x0FFFFFFF
All masters
SDRAM
core module 1
Module 1
0x90000000
0x00000000
0x8FFFFFFF
0x0FFFFFFF
SDRAM
core module 0
0x80000000
Module 0
0x00000000
Figure 4-3 Core module local and alias addresses
By reading the CM_STAT register, a processor can determine which core module it is
on and, therefore, the alias location of its own SDRAM (see CM_STAT (0x10000010)
on page 4-12).
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
4-5
Programmer’s Reference
4.2
Exception vector mapping
The convention for ARM cores is to map the exception vectors to begin at address 0.
However, the ARM940T core allows the vectors to be moved to 0xFFFF0000 by
writing to the V bit in coprocessor 15 register 1 (CP15c1). The value of the V bit at reset
is determined by the level on an external pin (VINITHI). To maintain compatibility
across all cores, the default reset value maps the vector to begin at address 0 (see the
ARM940T Technical Reference Manual).
When running applications with high vectors (at 0xFFFF0000 to 0xFFFFFFFF),
software must write the correct value to the coprocessor register. However, Integrator
motherboards have no physical memory at this location. This means that the MMU
must be programmed to map an area of physical memory to this virtual address. When
the core module is being used with a motherboard, an alternative is to implement an area
of physical memory on an expansion card or logic module.
4-6
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Programmer’s Reference
4.3
Core module registers
The core module status and control registers allow the processor to determine its
environment and to control some core module operations. The registers, listed in Table
4-2, are located at 0x10000000 and can only be accessed by the local processor.
Table 4-2 Core module status, control, and interrupt registers
Register Name
Address
Access
Description
CM_ID
0x10000000
Read
Core module identification register
CM_PROC
0x10000004
Read
Core module processor register
CM_OSC
0x10000008
Read/write
Core module oscillator values
CM_CTRL
0x1000000C
Read/write
Core module control
CM_STAT
0x10000010
Read
Core module status
CM_LOCK
0x10000014
Read/write
Core module lock
CM_SDRAM
0x10000020
Read/write
SDRAM status and control
CM_IRQ_STAT
0x10000040
Read
Core module IRQ status register
CM_IRQ_RSTAT
0x10000044
Read
Core module IRQ raw status register
CM_IRQ_ENSET
0x10000048
Read/write
Core module IRQ enable set register
CM_IRQ_ENCLR
0x1000004C
Write
Core module IRQ enable clear register
CM_SOFT_INTSET
0x10000050
Read/write
Core module software interrupt set
CM_SOFT_INTCLR
0x10000054
Write
Core module software interrupt clear
CM_FIQ_STAT
0x10000060
Read
Core module FIQ status register
CM_FIQ_RSTAT
0x10000064
Read
Core module FIQ raw status register
CM_FIQ_ENSET
0x10000068
Read/write
Core module FIQ enable set register
CM_FIQ_ENCLR
0x1000006C
Write
Core module FIR enable clear register
CM_SPD
0x10000100 to 0x100001FC
Read
SDRAM SPD memory
Note
All registers are 32-bits wide and do not support byte writes. Write operations must be
wordwide. Bits marked as reserved in the following sections should be preserved using
read-modify-write operations.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
4-7
Programmer’s Reference
4.3.1
CM_ID (0x10000000)
The core module ID register (CM_ID) is a read-only register that identifies the board
manufacturer, board type, and revision.
31
24 23
MAN
16 15
ARCH
1211
FPGA
43
BUILD
0
REV
Table 4-3 describes the core module ID register bits.
Table 4-3 CM_ID register bit descriptions
4.3.2
Bits
Name
Access
Function
31:24
MAN
Read
Manufacturer:
0x41 = ARM
23:16
ARCH
Read
Architecture:
0x00 = Generic ARM7x0T or ARM9x0T,
4 word SDRAM bursts
15:12
FPGA
Read
FPGA type:
0x00 = XC4036
11:4
BUILD
Read
Build value (ARM internal use)
3:0
REV
Read
Revision:
0x0 = Rev A
0x1 = Rev B
CM_PROC (0x10000004)
The core module processor register (CM_PROC) is a read-only register that contains
the value 0x00000000. This is provided for compatibility with processors that do not
have a system control coprocessor (CP15). For the ARM940T, information about the
processor can be obtained by reading coprocessor 15 register 0 (CP15 c0).
4-8
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Programmer’s Reference
4.3.3
CM_OSC (0x10000008)
The core module oscillator register (CM_OSC) is a read/write register that controls the
frequency of the clocks generated by the two clock generators (see Clock generators on
page 3-17). In addition, it provides information about processor bus mode setting.
31
25 24
Reserved
23 22
BMODE
12 11 10
20 19
L_OD
L_VDW
8 7
R C_OD
0
C_VDW
Before writing to the CM_OSC register, you must unlock it by writing the value
0x0000A05F to the CM_LOCK register. After writing the CM_OSC register, relock it
by writing any value other than 0x0000A05F to the CM_LOCK register.
Table 4-4 describes the core module oscillator register bits.
Table 4-4 CM_OSC register
ARM DUI 0125A
Bits
Name
Access
Function
31:25
Reserved
Use read-modify-write to preserve value.
24:23
BMOD
Read
This field contains 00 which indicates that the
processor bus mode is selected by writing to
CM_CTRL register (see CM_CTRL
(0x1000000C) on page 4-11).
22:20
L_OD
Read/write
Memory clock output divider:
000 = divide by 10
001 = divide by 2 (default)
010 = divide by 8
011 = divide by 4
100 = divide by 5
101 = divide by 7
110 = divide by 9
111 = divide by 6.
19:12
L_VDW
Read/write
Processor bus clock VCO divider word.
Defines the binary value of the V[7:0] pins of
the clock generator (V[8] is tied low).
00000100 = 6MHz (default with OD = 2).
© Copyright ARM Limited 1999. All rights reserved.
4-9
Programmer’s Reference
Table 4-4 CM_OSC register (continued)
4-10
Bits
Name
Access
Function
11
Reserved
Use read-modify-write to preserve value.
10:8
COREOD
Read/write
Core clock output divider:
000 = divide by 10
001 = divide by 2 (default)
010 = divide by 8
011 = divide by 4
100 = divide by 5
101 = divide by 7
110 = divide by 9
111 = divide by 6.
7:0
COREVCO
Read/write
Core clock VCO divider word. Defines the
binary value of the V[7:0] pins of the clock
generator (V[8] is tied low).
00000100 = 12MHz (default with OD = 2).
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Programmer’s Reference
4.3.4
CM_CTRL (0x1000000C)
The core module control register (CM_CTRL) is a read/write register that provides
control of a number of user-configurable features of the core module.
31
4
Reserved
3
2
1
0
RESET
REMAP
nMBDET
LED
Table 4-5 describes the core module control register bits.
Table 4-5 CM_CTL register
ARM DUI 0125A
Bits
Name
Access
Function
31:8
Reserved
Use read-modify-write to preserve value.
7:4
Reserved
Use read-modify-write to preserve value.
3
RESET
Write
This is used to reset the core module, the
motherboard on which it is mounted, and any core
modules in a stack. A reset is triggered by writing
a 1. Reading this bit always returns a 0 allowing
you to use read-modify-write operations without
masking the RESET bit.
2
REMAP
Read/write
This only has affect when the core module is
mounted onto a motherboard. When this is the
case, and this bit is a 0, accesses to the first
256KB (0x00000000 to 0x0003FFFF) of memory
are redirected into the motherboard.
1
nMBDET
Read
This bit indicates whether or not the core module
is mounted on a motherboard:
0 = mounted on motherboard
1 = standalone.
0
LED
Read/write
This bit controls the green MISC LED on the core
module:
0 = LED OFF
1 = LED ON.
© Copyright ARM Limited 1999. All rights reserved.
4-11
Programmer’s Reference
4.3.5
CM_STAT (0x10000010)
The core module status register (CM_STAT) is a read-only register that can be read to
determine where in a multi-core module stack this core module is positioned.
31
8
7
Reserved
0
ID
Table 4-6 describes the core module status register bits.
Table 4-6 CM_STAT register
4-12
Bit
Name
Access
Function
31:8
Reserved
Use read-modify-write to preserve value.
7:0
ID
Read
Card number:
0x00 = core module 0
0x01 = core module 1
0x02 = core module 2
0x03 = core module 3
0xFF = invalid or no motherboard attached.
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Programmer’s Reference
4.3.6
CM_LOCK (0x10000014)
The core module lock register (CM_LOCK) is a read/write register that is used to
control access to the CM_OSC register, allowing it to be locked and unlocked. This
mechanism prevents the CM_OSC register from being overwritten accidently.
31
17
Reserved
16
15
LOCKED
0
LOCKVAL
Table 4-7 describes the core module lock register bits.
Table 4-7 CM_LOCK register
ARM DUI 0125A
Bits
Name
Access
Function
16
LOCKED
Read
This bit indicates if the CM_OSC register is
locked or unlocked:
0 = unlocked
1 = locked.
15:0
LOCKVAL
Read/write
Write the value 0x0000A05F to this register
to enable write accesses to the CM_OSC
register.
Write any other value to this register to lock
the CM_OSC register.
© Copyright ARM Limited 1999. All rights reserved.
4-13
Programmer’s Reference
4.3.7
CM_SDRAM (0x10000020)
The SDRAM status and control register (CM_SDRAM) is a read/write register used to
set the configuration parameters for the SDRAM DIMM. This control is necessary
because of the variety of module sizes and types available.
Writing a value to this register automatically updates the mode register on the SDRAM
DIMM.
31
20 19
Reserved
16 15
12 11
NBANKS NCOLS
8 7
NROWS
6
R
5
SPDOK
4
2
MEMSIZE
1
0
CASLAT
Table 4-8 describes the SDRAM status and control register bits.
Table 4-8 CM_SDRAM register
4-14
Bits
Name
Access
Function
31:20
Reserved
Use read-modify-write to preserve value.
19:16
NBANKS
Read/write
Number of SDRAM banks. Should be set to
the same value as byte 5 of SPD EEPROM.
15:12
NCOLS
Read/write
Number of SDRAM columns. Should be set
to the same value as byte 4 of SPD EEPROM.
11:8
NROWS
Read/write
Number of SDRAM rows. Should be set to
the same value as byte 3 of SPD EEPROM.
7:6
Reserved
Use read-modify-write to preserve value.
5
SPDOK
Read
This bit indicates that the automatic copying
of the SPD data from the SDRAM module
into CM_SPDMEM is complete:
1 = SPD data ready
0 = SPD data not available.
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Programmer’s Reference
Table 4-8 CM_SDRAM register (continued)
Bits
Name
Access
Function
4:2
MEMSIZE
Read/write
These bits specify the size of the SDRAM
module fitted to the core module. The bits are
encoded as follows:
000 = 16MB
001 = 32MB
010 = 64MB (default)
011 = 128MB
100 = 256MB
101 = Reserved
110 = Reserved.
1:0
CASLAT
Read/write
These bits specify the CAS latency set for the
core module. The bits are encoded as follows:
00 = Reserved
01 = Reserved
10 = 2 cycles (default)
11 = 3 cycles.
Note
Before the SDRAM is used it is necessary to read the SPD memory and program the
CM_SDRAM register with the parameters indicated in Table 4-8. If these values are not
correctly set then SDRAM accesses may be slow or unreliable. See CM_SPD
(0x10000100 to 0x100001FC) on page 4-16.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
4-15
Programmer’s Reference
4.3.8
CM_SPD (0x10000100 to 0x100001FC)
This area of memory contains a copy of the SPD data from the SPD EEPROM on the
DIMM. Because accesses to the EEPROM are very slow, the data is copied to this
memory during board initialization to allow faster random access to the SPD data (see
Serial presence detect on page 3-6). The SPD memory contains 256 bytes of data, the
most important of which are as shown in Table 4-9.
Table 4-9 SPD memory contents
Byte
Contents
2
Memory type
3
Number of row addresses
4
Number of column addresses
5
Number of banks
31
Module bank density (MB
divided by 4)
18
CAS latencies supported
63
Checksum
64:71
Manufacturer
73:90
Module part number
Check for valid SPD data as follows:
1.
Add together all bytes 0 to 62.
2.
Logically AND the result with 0xFF.
3.
Compare the result with byte 63.
If the two values match, then the SPD data is valid.
Note
A number of SDRAM DIMMs do not comply with the JEDEC standard and do not
implement the checksum byte. The Integrator is not guaranteed to operate with
non-compliant DIMMs.
The code segment shown in Example 4-1 on page 4-17 can be used to correctly setup
and remap the SDRAM.
4-16
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Programmer’s Reference
Example 4-1
CM_BASE
SPD_BASE
EQU
EQU
0x10000000
0x10000100
; base address of Core Module registers
; base address of SPD information
lightled
LDR
MOV
STR
; turn on header
r0, =CM_BASE
;
r1,#5
;
r1,[r0,#0xc]
;
; setup SDRAM
LED and remap memory
load register base address
set remap and led bits
write the register
readspdbit
LDR
AND
CMP
BNE
; check SPD bit is set
r1,[r0,#0x20]
; read the status register
r1,r1,#0x20
; mask SPD bit (5)
r1,#0x20
; test if set
readspdbit
; branch until the SPD memory has been read
LDR
LDRB
LDRB
LDRB
LDRB
MUL
MOV
CMP
BNE
MOV
B
; work out the
r0, =SPD_BASE
r1,[r0,#3]
r2,[r0,#4]
r3,[r0,#5]
r4,[r0,#31]
r5,r4,r3
r5,r5,ASL#2
r5,#0x10
not16
r6,#0x2
writesize
SDRAM size
; point at SPD memory
; number of row address lines
; number of column address lines
; number of banks
; module bank density
; calculate size of SDRAM (MB divided by 4)
; size in MB
; is it 16MB?
; if no, move on
; store size and CAS latency of 2
CMP
BNE
MOV
B
r5,#0x20
not32
r6,#0x6
writesize
; is it 32MB?
; if no, move on
; store size and CAS latency of 2
setupsdram
not16
not32
CMP
BNE
MOV
B
ARM DUI 0125A
r5,#0x40
not64
r6,#0xa
writesize
; is it 64MB?
; if no, move on
; store size and CAS latency of 2
© Copyright ARM Limited 1999. All rights reserved.
4-17
Programmer’s Reference
not64
CMP
BNE
MOV
B
r5,#0x80
not128
r6,#0xe
writesize
; is it 128MB?
; if no, move on
; store size and CAS latency of 2
not128
; if it is none of these sizes then it is either 256MB, or
; there is no SDRAM fitted so default to 256MB.
MOV
r6,#0x12
; store size and CAS latency of 2
writesize
MOV
ORR
ORR
ORR
LDR
STR
4-18
r1,r1,ASL#8
r2,r1,r2,ASL#12
r3,r2,r3,ASL#16
r6,r6,r3
r0, =CM_BASE
r6,[r0,#0x20]
;
;
;
;
;
get row address lines for SDRAM register
OR in column address lines
OR in number of banks
OR in size and CAS latency
point at module registers
; store SDRAM parameters
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Programmer’s Reference
4.4
Interrupt registers
The core module provides a 3-bit IRQ controller and 3-bit FIQ controller to support the
debug communications channel used for passing information between applications
software and the debugger. The interrupt control registers are listed in Table 4-10.
Table 4-10 Interrupt controller registers
Register Name
Address
Access
Size
Description
CM_IRQ_STAT
0x10000040
Read
3 bits
Core module IRQ status register
CM_IRQ_RSTAT
0x10000044
Read
3 bits
Core module IRQ raw status register
CM_IRQ_ENSET
0x10000048
Read/write
3 bits
Core module IRQ enable set register
CM_IRQ_ENCLR
0x1000004C
Write
3 bits
Core module IRQ enable clear register
CM_SOFT_INTSET
0x10000050
Read/write
1 bit
Core module software interrupt set
CM_SOFT_INTCLR
0x10000054
Write
1 bit
Core module software interrupt clear
CM_FIQ_STAT
0x10000060
Read
3 bits
Core module FIQ status register
CM_FIQ_RSTAT
0x10000064
Read
3 bits
Core module FIQ raw status register
CM_FIQ_ENSET
0x10000068
Read/write
3 bits
Core module FIQ enable set register
CM_FIQ_ENCLR
0x1000006C
Write
3 bits
Core module FIR enable clear register
The IRQ and FIQ controllers each provide three registers for controlling and handling
interrupts. These are:
•
status register
•
raw status register
•
enable register, which is accessed using the enable set and enable clear locations.
The way that the interrupt enable, clear, and status bits function for each interrupt is
illustrated in Figure 4-4 on page 4-20 and described in the following subsections. The
illustration shows the control for one IRQ bit. The remaining IRQ bits and FIQ bits are
controlled in a similar way.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
4-19
Programmer’s Reference
Enable set
Set
Enable
Enable clear
Clear
Status
Interrupt source
Raw status
nIRQ
From other
bit slices
Figure 4-4 Interrupt control
4.4.1
CM_IRQ_STAT (0x10000040)/CM_FIQ_STAT (0x10000060)
The status register contains the logical AND of the bits in the raw status register and the
enable register.
4.4.2
CM_IRQ_RSTAT (0x10000044)/CM_FIQ_RSTAT (0x10000064)
The raw status register indicates the signal levels on the interrupt request inputs. A bit
set to 1 indicates that the corresponding interrupt request is active.
4.4.3
CM_IRQ_ENSET (0x10000048)/CM_FIQ_ENSET (0x10000068)
The enable set locations are used to set bits in the enable register as follows:
•
set bits in the enable register by writing to the ENSET location for the required
IRQ or FIQ controller:
1 = SET the bit.
•
4-20
0 = leave the bit unchanged.
read the current state of the enable bits from the ENSET location.
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Programmer’s Reference
4.4.4
CM_IRQ_ENCLR(0x1000004C)/CM_FIQ_ENCLR (0x1000006C)
The clear set locations are used to set bits in the enable register as follows:
•
clear bits in the enable register by writing to the ENCLR location for the
required IRQ or FIQ controller:
1 = CLEAR the bit.
0 = leave the bit unchanged.
4.4.5
Interrupt register bit assignment
The bit assignments for the IRQ and FIQ status, raw status and enable register are
shown in Table 4-11.
Table 4-11 IRQ and FIQ register bit assignment
ARM DUI 0125A
Bit
Name
Function
2
COMMTx
Debug communications transmit interrupt.
This interrupt indicates that the communications channel is
available for the processor to pass messages to the debugger.
1
COMMRx
Debug communications receive interrupt.
This interrupt indicates to the processor that messages are
available for the processor to read.
0
SOFT
Software interrupt
© Copyright ARM Limited 1999. All rights reserved.
4-21
Programmer’s Reference
4.4.6
CM_SOFT_INTSET (0x10000050)/CM_SOFT_INTCLT (0x10000054)
The core module interrupt controller provides a register for controlling and clearing
software interrupts. This register is accessed using the software interrupt set and
software interrupt clear locations. The set and clear locations are used as follows:
•
Set the software interrupt by writing to the CM_SOFT_INTSET location:
1 = SET the software interrupt
0 = leave the software interrupt unchanged.
•
Read the current state of the of the software interrupt register from the
CM_SOFT_INTSET location. A bit set to 1 indicates that the corresponding
interrupt request is active.
•
Clear the software interrupt by writing to the CM_SOFT_INTCLR location:
1 = CLEAR the software interrupt.
0 = leave the software interrupt unchanged.
The bit assignment for the software interrupt register is shown in Table 4-12.
Table 4-12 IRQ register bit assignment
Bit
Name
Function
0
SOFT
Software interrupt
Note
The software interrupt described in this section is used by software to generate IRQs or
FIQs. It should not be confused with the ARM SWI software interrupt instruction. See
the ARM Architecture Reference Manual.
4-22
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Appendix A
Signal Descriptions
This index provides a summary of signals present on the core module main connectors.
It contains the following sections:
•
HDRA on page A-2
•
HDRB on page A-4.
Note
For the Multi-ICE connector pinout and signal descriptions see JTAG signals on
page 3-24.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
A-1
Signal Descriptions
A.1
HDRA
Figure A-1 shows the pin numbers of the HDRA plug and socket. All pins on the HDRA
socket are connected to the corresponding pins on the HDRA plug.
Pin numbers for 200-way plug,
viewed from above board
1
101
2
102
3
103
Samtec TOLC series
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
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
A0
GND
GND
D0
D1
A1
A2
D2
GND
A3
GND
D3
D4
A4
A5
D5
GND
A6
GND
D6
D7
A7
A8
D8
GND
A9
GND
D9
D10
A10
A11
D11
GND
A12
GND
D12
D13
A13
A14
D14
GND
A15
GND
D15
D16
A16
A17
D17
GND
A18
GND
D18
D19
A19
A20
D20
GND
A21
GND
D21
D22
A22
A23
D23
GND
A24
GND
D24
D25
A25
A26
D26
GND
A27
GND
D27
D28
A28
A29
D29
GND
A30
GND
D30
D31
A31
B0
C0
GND
B1
GND
C1
C2
B2
B3
C3
GND
B4
GND
C4
C5
B5
B6
C6
GND
B7
GND
C7
C8
B8
B9
C9
GND
B10
GND
C10
C11
B11
B12
C12
GND
B13
GND
C13
C14
B14
B15
C15
GND
B16
GND
C16
C17
B17
B18
C18
GND
B19
GND
C19
C20
B20
B21
C21
GND
B22
GND
C22
C23
B23
B24
C24
GND
B25
GND
C25
C26
B26
B27
C27
GND
B28
GND
C28
C29
B29
B30
C30
GND
B31
GND
C31
3V3
5V
3V3
12V
3V3
5V
3V3
12V
3V3
5V
3V3
12V
3V3
5V
3V3
12V
3V3
5V
3V3
12V
3V3
5V
3V3
12V
3V3
5V
3V3
12V
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
Figure A-1 HDRA plug pin numbering
A-2
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Signal Descriptions
The signals present on the pins labeled A[31:0], B[31:0], and C[31:0] are described in
Table A-1.
Table A-1 Bus bit assignment (for an AMBA ASB bus )
Pin label
Name (ASB)
Description
A[31:0]
System address bus
System address bus
B[31:0]
Not used
-
C[31:0]
System control bus
See remainder of table.
C[31:16]
Not used
-
C15
BLOK
Locked transaction
C14
BLAST
Last response
C13
BERROR
Error response
C12
BWAIT
Wait response
C11
BWRITE
Write transaction
C10
Not used
-
C[9:8]
BPROT[1:0]
Transaction protection type
C7
Not used
-
C[6:5]
BURST[1:0]
Transaction burst size
C4
Not used
-
C[3:2]
BSIZE[1:0]
Transaction width
C[1:0]
BTRAN[1:0]
Transaction type
D[31:0]
System data bus
System data bus
Note
Table A-1 shows signal descriptions for an AMBA ASB bus implementation.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
A-3
Signal Descriptions
A.2
HDRB
The HDRB plug and socket have slightly different pinouts, as described below.
A.2.1
HDRB socket pinout
Figure A-2 shows the pin numbers of the socket HDRB on the underside of the core
module, viewed from above the core module.
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
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
E0
GND
GND
F0
F1
E1
E2
F2
GND
E3
GND
F3
F4
E4
E5
F5
GND
E6
GND
F6
F7
E7
E8
F8
GND
E9
GND
F9
F10
E10
E11
F11
GND
E12
GND
F12
F13
E13
E14
F14
GND
E15
GND
F15
F16
E16
E17
F17
GND
E18
GND
F18
F19
E19
E20
F20
GND
E21
GND
F21
F22
E22
E23
F23
GND
E24
GND
F24
F25
E25
E26
F26
GND
E27
GND
F27
F28
E28
E29
F29
GND
E30
GND
F30
F31
E31
G0
G8
GND
G1
GND
G9
G10
G2
G3
G11
GND
G4
GND
G12
G13
G5
G6
G14
G16
G7
GND
G15
-12V
5V
3V3
12V
-12V
5V
3V3
12V
-12V
5V
3V3
12V
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
Figure A-2 HDRB socket pin numbering
A-4
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Signal Descriptions
A.2.2
HDRB plug pinout
Figure A-3 shows the pin numbers of the HDRB plug on the top of the core module.
Pin numbers for 120-way plug,
viewed from above board
61
1
62
2
63
3
Samtec TOLC series
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
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
E1
GND
GND
F0
F1
E2
E3
F2
GND
E0
GND
F3
F4
E5
E6
F5
GND
E7
GND
F6
F7
E4
E9
F8
GND
E10
GND
F9
F10
E11
E8
F11
GND
E13
GND
F12
F13
E14
E15
F14
GND
E12
GND
F15
F16
E17
E18
F17
GND
E19
GND
F18
F19
E16
E21
F20
GND
E22
GND
F21
F22
E23
E20
F23
GND
E25
GND
F24
F25
E26
E27
F26
GND
E24
GND
F27
F28
E29
E30
F29
GND
E31
GND
F30
F31
E28
G0
G8
GND
G1
GND
G9
G10
G2
G3
G11
GND
G4
GND
G12
G13
G5
G6
G14
G16
G7
GND
G15
-12V
5V
3V3
12V
-12V
5V
3V3
12V
-12V
5V
3V3
12V
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
Figure A-3 HDRB plug pin numbering
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
A-5
Signal Descriptions
A.2.3
Through-board signal connections
The signals on the pins labeled E[31:0] are cross-connected between the plug and socket
so that the signals are rotated through the stack in groups of four. For example, the first
block of four are connected as shown in Table A-2.
Table A-2 Signal cross-connections (example)
Plug
Socket
E0
connects to
E1
E1
connects to
E2
E2
connects to
E3
E3
connects to
E0
For details about the signal rotation scheme, see System bus signal routing on
page 3-15.
The signals on the pins labeled F[31:0] are connected so that pins on the socket are
connected to the corresponding pins on the plug.
The signals on G[15:8] and G[5:0] are connected so that pins on the socket are
connected to the corresponding pins on the plug.
Pins G[7:6] carry the JTAG TDI and TDO signals. The signal TDO is routed through
devices on each baord as it passes up through the stack (see JTAG signals on page 3-24).
A-6
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Signal Descriptions
A.2.4
HDRB signal descriptions
Table A-3 describes the signals on the pins labeled E[31:0], F[31:0], and G[15:0].
Table A-3 HDRB signal description
ARM DUI 0125A
Pin label
Name
Description
E[31:28]
SYSCLK[3:0]
System clock (ASB clock) to each core
module/expansion card
E[27:24]
nPPRES[3:0]
Processor present
E[23:20]
nIRQ[3:0]
Interrupt request to processors 3, 2, 1, and 0
respectively
E[19:16]
nFIQ[3:0]
Fast interrupt requests to processors 3, 2, 1, and
0 respectively
E[15:12]
ID[3:0]
Core module stack position indicator
E[11:8]
Reserved
-
E[7:4]
AGNT[3:0]
System bus grant
E[3:0]
AREQ[3:0]
System bus request
F[31:0]
-
Not connecetd
G16
nRTCKEN
RTCK AND gate enable
G[15:14]
CFGSEL[1:0]
FPGA configuration select
G13
nCFGEN
Sets motherboard into configuration mode
G12
nSRST
Multi-ICE reset (open collector)
G11
FPGADONE
Indicates when FPGA configurarion is
complete (open collector)
G10
RTCK
Returned JTAG test clock
G9
nSYSRST
Buffered system reset
G8
nTRST
JTAG reset
G7
TDO
JTAG test data out
G6
TDI
JTAG test data in
G5
TMS
JTAG test mode select
© Copyright ARM Limited 1999. All rights reserved.
A-7
Signal Descriptions
Table A-3 HDRB signal description (continued)
Pin label
Name
Description
G4
TCK
JTAG test clock
G[3:1]
MASTER[2:0]
Master ID. Binary encoding of the master
currently performing a transfer on the bus.
Corresponds to the module ID and to the
AREQ and AGNT line numbers.
G0
nMBDET
Motherboard detect pin
Note
Table A-3 shows signal descriptions for an AMBA ASB bus implementation.
A-8
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Appendix B
Specifications
This appendix contains the specifications for the ARM Integrator/CM940T core
module. It contains the following sections:
•
Electrical specification on page B-2
•
Timing specification on page B-3
•
Mechanical details on page B-4.
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
B-1
Specifications
B.1
Electrical specification
Table B-1 shows the core module electrical characteristics for the system bus interface.
The core module uses 3.3V and 5V source. The 12V inputs are supplied by the
motherboard but not used by the core module.
Table B-1 Core module electrical characteristics
B-2
Symbol
Description
Min
Max
Unit
3V3
Supply voltage (interface signals)
3.1
3.5
V
5V
Supply voltage
4.75
5.25
V
VIH
High-level input voltage
2.0
3.6
V
VIL
Low-level input voltage
0
0.8
V
VOH
High-level output voltage
2.4
-
V
VOL
Low-level output voltage
-
0.4
V
CIN
Input capacitance
-
20
pF
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Specifications
B.2
Timing specification
Table B-2 provides the operating timing characteristics for the system bus interface
signals.
Table B-2 Core module timing (preliminary)
Symbol
Description
Min
Max
Units
FMAX
Operating frequency
-
25
MHz
TCH
Clock HIGH
19
-
ns
TCL
Clock LOW
19
-
ns
TCO
Clock to output – signals generated and
sampled on same clock edge
-
16.0
ns
Clock to output – signals generated and
sampled on different clock edge
-
8.0
ns
Input to clock – signals generated and
sampled on same clock edge
-
8.0
ns
Input to clock – signals generated and
sampled on different clock edge
-
4.0
ns
TBPD
Motherboard propagation delay (for
guidance only)
-
1.0
ns
TSKEW
Motherboard clock skew for guidance
only)
-
1.0
ns
TIC
ARM DUI 0125A
© Copyright ARM Limited 1999. All rights reserved.
B-3
Specifications
B.3
Mechanical details
The core module is designed to be stackable on a number of different motherboards. Its
size allows it to be mounted onto a CompactPCI motherboard while allowing the
motherboard to be installed in a card cage.
Figure B-1 shows the mechanical outline of the core module.
148.0
10.0
128.0
10.0
Detail A
HDRA
HDRB
81.0
130-way connector
(4 col x 30 row)
Plug on top and
socket on underside
100.0
200-way connector
(4 col x 50 row)
Plug on top and
socket on underside
Detail B
Pin numbers for 168-way
SDRAM DIMM connector
shown
1
2
85
86
Detail B
Memory DIMM
Measurement datum is
line shown through pins
Memory DIMM connector is 25º type
which overhangs the edge of the board
Detail A
10.0
Pin numbers for 200-way plug,
viewed from above board
Pin numbers for 200-way socket,
viewed from below board
10.0
1
101
101
1
2
102
102
2
3
103
103
3
Samtec TOLC series
Samtec TOLC series
Connector footprint
Figure B-1 Board outline
B-4
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Index
The items in this index are listed in alphabetic order, with symbols and numerics appearing at the end. The
references given are to page numbers.
A
About this book
feedback xi
typographical conventions ix
Access arbitration, SDRAM 3-6
Accesses
boot ROM 4-2
SSRAM 4-2
Accesses SDRAM 4-4
Alias SDRAM addresses 4-5
ARM web address ii
Assmbled Integrator system 2-5
B
Block diagram 1-4
Boot ROM, accesses 4-2
Bus bridge, system 3-11
Bus clock, processor 3-19
ARM DUI 0125A
Bus operating modes
3-16
C
Calculating the CORECLK speed 3-18
Calculating the LCLK speed 3-19
CAS latency, setting 4-15
CE Declaration of Conformity iii
Checking for valid SPD data 4-16
Clock generator 1-6, 3-17
Clock, reference 3-20
CM_CTL register 4-2
CM_CTRL register 4-11
CM_FIQ_ENCLR register 4-19
CM_FIQ_ENSET register 4-19
CM_FIQ_RSTAT register 4-19
CM_FIQ_STAT register 4-19
CM_ID Register 4-8
CM_ID register 4-5
CM_IRQ_ENCLR register 4-19
CM_IRQ_ENSET register 4-19
CM_IRQ_RSTAT register 4-19
CM_IRQ_STAT register 4-19
CM_LOCK register 4-13
CM_OSC register 3-18, 3-19, 4-9
CM_PROC register 4-8
CM_SDRAM 3-7
CM_SDRAM register 4-14
CM_SOFT_INTCLR register 4-19
CM_SOFT_INTSET register 4-19
CM_SPD 3-7
CM_STAT register 4-12
CONFIG LED 3-21
CONFIG link 3-21
Configuration mode 3-23
Connecting Multi-ICE 2-4
Connecting power 2-3
© Copyright ARM Limited 1999. All rights reserved.
Index-i
Index
Connectors
HDRA and HDRB 1-3
Multi-ICE 2-4
power 2-3
Controller
clock 1-6, 3-17
reset 1-5, 3-8
SDRAM 1-5, 3-6
SSRAM 3-3
Controllers
FIQ 4-19
IRQ 4-19
Core module control register 4-11
Core module FPGA 1-5
Core module ID 2-6
Core module registers 4-7
Core module, stack position 4-12
CORECLK 3-17, 3-18
D
ii
E
F
FCC notice iii
FIFOs 3-11
FIQ controller 4-19
Fitting SDRAM 2-2
FPGA 1-5
G
LCLK 3-17, 3-19
Local SDRAM 4-4
Location of connectors
Lock register 4-13
1-3
HDRA 3-15
HDRA and HDRB connectors
MBDET bit 4-11
Memory
volatile 1-6
Memory map 4-2
MEMSIZE 4-15
Microprocessor core 3-2
MISC LED control 4-11
Motherboard detect 4-3
Motherboard, attaching the core
module 2-5
Multi-ICE 1-7, 3-21
connecting 2-4
Multi-ICE connector 1-3
1-3
nLCLK 3-19
nMBDET 3-22
Normal debug mode
Notices, FCC iii
2-6
4-21
3-18, 3-19
P
Power connector 1-3, 2-3
Powering an attached core module
Precautions 1-11
Preventing damage 1-11
Processor bus clock 3-19
Processor core clock 3-18
Processor register 4-8
Product feedback xi
Product status ii
Proprietary notice ii
2-6
Raw status register, interrupt 4-20
REFCLK 3-17, 3-20
Reference clock 3-20
Register addresses 4-7
Registers 1-6
CM_CTL 4-2
CM_CTRL 4-11
CM_FIQ_ENCLR 4-19
CM_FIQ_ENSET 4-19
CM_FIQ_RSTAT 4-19
CM_FIQ_STAT 4-19
CM_ID 4-5, 4-8
CM_IRQ_ENCLR 4-19
CM_IRQ_ENSET 4-19
CM_IRQ_RSTAT 4-19
CM_IRQ_STAT 4-19
CM_LOCK 4-13
CM_OSC 3-18, 3-19, 4-9
CM_PROC 4-8
CM_SDRAM 4-14
CM_SOFT_INTCLR 4-19
CM_SOFT_INTSET 4-19
CM_STAT 4-12
Related publications x
REMAP bit 4-11
Remap, effect of 4-2
Reset control bit 4-11
Reset controller 1-5, 3-8
S
3-23
O
I
Output divider
R
N
4-5
H
Index-ii
JTAG 3-21
JTAG debug 1-7
JTAG scan path 3-22
JTAG signals 3-24
JTAG, connecting 2-4
M
Electromagnetic conformity iii
Enable register, interrupt 4-20, 4-21
Ensuring safety 1-11
Exception vector mapping 4-6
ID, core module
J
L
Debug comms channel 4-19
Debugging modes 3-23
DIMM socket 1-3
Document confidentiality status
Global SDRAM
Interface
system bus 1-5
Interrupt control 4-20
Interrupt register bit assignment
Interrupt registers 4-19
Interupt status 4-20
IRQ and FIQ register bit
assignment 4-21
IRQ controller 4-19
Operating mode, SDRAM
Oscillator register 4-9
3-6
SDRAM
fitting 2-2
SDRAM access arbitration 3-6
SDRAM accesses 4-4
SDRAM controller 1-5, 3-6
SDRAM global access 4-5
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
Index
SDRAM operating mode 3-6
SDRAM repeat mapping 4-4
SDRAM status and control register 4-14
SDRAM, SPD memory 4-16
Serial presence detect 3-6
Setting CAS latency 4-15
Setting SDRAM size 4-15
Setup
power connections 2-3
standalone 2-2
Software interrupt registers 4-22
Software reset 4-11
SPD memory 4-16
SPDOK bit 4-14
SSRAM accesses 4-2
SSRAM controller 3-3
Standalone core module 2-2
Status and configuration registers 1-6
Status register 4-12
Status register, interrupt 4-20
Supplying power 2-3
System architecture 1-4
System bus
operating modes 3-16
System bus bridge 1-5, 3-11
System bus signal routing 3-15
T
Typographical conventions
ix
U
Using the core module with a
motherboard 2-5
V
VCO divider 3-18, 3-19
Vector mapping 4-6
Volatile memory 1-6
W
Web site, ARM
ARM DUI 0125A
ii
© Copyright ARM Limited 1999. All rights reserved.
Index-iii
Index
Index-iv
© Copyright ARM Limited 1999. All rights reserved.
ARM DUI 0125A
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