sprufn3 - Texas Instruments

TMS320F2802x/TMS320F2802xx Piccolo System
Control and Interrupts
Reference Guide
Literature Number: SPRUFN3D
January 2009 – Revised February 2013
Contents
Preface ....................................................................................................................................... 8
1
Flash and OTP Memory ...................................................................................................... 10
.......................................................................................................... 10
........................................................................................................... 10
1.3
Flash and OTP Power Modes ........................................................................................ 11
1.4
Flash and OTP Registers ............................................................................................. 16
2
Code Security Module (CSM) .............................................................................................. 22
2.1
Functional Description ................................................................................................. 22
2.2
CSM Impact on Other On-Chip Resources ......................................................................... 24
2.3
Incorporating Code Security in User Applications ................................................................. 24
2.4
Do's and Don'ts to Protect Security Logic .......................................................................... 30
2.5
CSM Features - Summary ............................................................................................ 30
3
Clocking ........................................................................................................................... 31
3.1
Clocking and System Control ........................................................................................ 31
3.2
OSC and PLL Block ................................................................................................... 35
3.3
Low-Power Modes Block ............................................................................................. 53
3.4
CPU Watchdog Block ................................................................................................. 56
3.5
32-Bit CPU Timers 0/1/2 .............................................................................................. 62
4
General-Purpose Input/Output (GPIO) .................................................................................. 67
4.1
GPIO Module Overview ............................................................................................... 67
4.2
Configuration Overview ............................................................................................... 72
4.3
Digital General Purpose I/O Control ................................................................................. 74
4.4
Input Qualification ...................................................................................................... 75
4.5
GPIO and Peripheral Multiplexing (MUX) ........................................................................... 80
4.6
Register Bit Definitions ................................................................................................ 84
5
Peripheral Frames ............................................................................................................ 100
5.1
Peripheral Frame Registers ......................................................................................... 100
5.2
EALLOW-Protected Registers ...................................................................................... 102
5.3
Device Emulation Registers ......................................................................................... 106
5.4
Write-Followed-by-Read Protection ................................................................................ 109
6
Peripheral Interrupt Expansion (PIE) .................................................................................. 110
6.1
Overview of the PIE Controller ..................................................................................... 110
6.2
Vector Table Mapping ............................................................................................... 113
6.3
Interrupt Sources ..................................................................................................... 115
6.4
PIE Configuration Registers ........................................................................................ 124
6.5
PIE Interrupt Registers .............................................................................................. 125
6.6
External Interrupt Control Registers ............................................................................... 133
7
VREG/BOR/POR ............................................................................................................... 135
7.1
On-chip Voltage Regulator (VREG) ................................................................................ 135
7.2
On-chip Power-On Reset (POR) and Brown-Out Reset (BOR) Circuit ....................................... 136
Appendix A Revision History ..................................................................................................... 137
2
1.1
Flash Memory
1.2
OTP Memory
Table of Contents
SPRUFN3D – January 2009 – Revised February 2013
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List of Figures
1
Flash Power Mode State Diagram ...................................................................................... 12
2
Flash Pipeline .............................................................................................................. 14
3
Flash Configuration Access Flow Diagram
4
Flash Options Register (FOPT) .......................................................................................... 17
5
Flash Power Register (FPWR)........................................................................................... 17
6
Flash Status Register (FSTATUS) ...................................................................................... 18
7
Flash Standby Wait Register (FSTDBYWAIT)
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
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24
25
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31
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39
40
41
42
43
44
45
46
47
............................................................................
........................................................................
Flash Standby to Active Wait Counter Register (FACTIVEWAIT) .................................................
Flash Wait-State Register (FBANKWAIT) .............................................................................
OTP Wait-State Register (FOTPWAIT) ................................................................................
CSM Status and Control Register (CSMSCR).........................................................................
Password Match Flow (PMF) ...........................................................................................
Clock and Reset Domains ................................................................................................
Peripheral Clock Control 0 Register (PCLKCR0) .....................................................................
Peripheral Clock Control 1 Register (PCLKCR1) .....................................................................
Peripheral Clock Control 3 Register (PCLKCR3) .....................................................................
Low-Speed Peripheral Clock Prescaler Register (LOSPCP) ........................................................
Clocking Options...........................................................................................................
Internal Oscillator n Trim (INTOSCnTRIM) Register .................................................................
Clocking (XCLK) Register ................................................................................................
Clock Control (CLKCTL) Register ......................................................................................
OSC and PLL Block .......................................................................................................
Oscillator Logic Diagram .................................................................................................
Clock Fail Interrupt ........................................................................................................
XCLKOUT Generation ....................................................................................................
PLLCR Change Procedure Flow Chart .................................................................................
PLLCR Register Layout ..................................................................................................
PLL Status Register (PLLSTS) ..........................................................................................
PLL Lock Period (PLLLOCKPRD) Register ............................................................................
Low Power Mode Control 0 Register (LPMCR0) ......................................................................
CPU Watchdog Module ...................................................................................................
System Control and Status Register (SCSR) .........................................................................
Watchdog Counter Register (WDCNTR) ...............................................................................
Watchdog Reset Key Register (WDKEY) ..............................................................................
Watchdog Control Register (WDCR) ...................................................................................
CPU-Timers ................................................................................................................
CPU-Timer Interrupts Signals and Output Signal .....................................................................
TIMERxTIM Register (x = 0, 1, 2) .......................................................................................
TIMERxTIMH Register (x = 0, 1, 2) .....................................................................................
TIMERxPRD Register (x = 0, 1, 2) ......................................................................................
TIMERxPRDH Register (x = 0, 1, 2) ....................................................................................
TIMERxTCR Register (x = 0, 1, 2) ......................................................................................
TIMERxTPR Register (x = 0, 1, 2) ......................................................................................
TIMERxTPRH Register (x = 0, 1, 2) ...................................................................................
GPIO0 to GPIO31 Multiplexing Diagram ...............................................................................
GPIO32, GPIO33 Multiplexing Diagram ................................................................................
JTAG Port/GPIO Multiplexing ............................................................................................
SPRUFN3D – January 2009 – Revised February 2013
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List of Figures
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19
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3
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48
Analog/GPIO Multiplexing ................................................................................................ 71
49
Input Qualification Using a Sampling Window ......................................................................... 76
50
Input Qualifier Clock Cycles .............................................................................................. 79
51
GPIO Port A MUX 1 (GPAMUX1) Register ............................................................................ 84
52
GPIO Port A MUX 2 (GPAMUX2) Register ............................................................................ 85
53
GPIO Port B MUX 1 (GPBMUX1) Register ............................................................................ 86
54
Analog I/O MUX (AIOMUX1) Register .................................................................................. 87
55
GPIO Port A Qualification Control (GPACTRL) Register
88
56
GPIO Port B Qualification Control (GPBCTRL) Register
89
57
58
59
60
61
62
63
64
65
66
67
68
69
70
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90
4
............................................................
............................................................
GPIO Port A Qualification Select 1 (GPAQSEL1) Register ..........................................................
GPIO Port A Qualification Select 2 (GPAQSEL2) Register ..........................................................
GPIO Port B Qualification Select 1 (GPBQSEL1) Register ..........................................................
GPIO Port A Direction (GPADIR) Register ............................................................................
GPIO Port B Direction (GPBDIR) Register ............................................................................
Analog I/O DIR (AIODIR) Register ......................................................................................
GPIO Port A Pullup Disable (GPAPUD) Registers ...................................................................
GPIO Port B Pullup Disable (GPBPUD) Registers ...................................................................
GPIO Port A Data (GPADAT) Register ................................................................................
GPIO Port B Data (GPBDAT) Register ................................................................................
Analog I/O DAT (AIODAT) Register ....................................................................................
GPIO Port A Set, Clear and Toggle (GPASET, GPACLEAR, GPATOGGLE) Registers .......................
GPIO Port B Set, Clear and Toggle (GPBSET, GPBCLEAR, GPBTOGGLE) Registers .......................
Analog I/O Toggle (AIOSET, AIOCLEAR, AIOTOGGLE) Register .................................................
GPIO XINTn Interrupt Select (GPIOXINTnSEL) Registers ..........................................................
GPIO Low Power Mode Wakeup Select (GPIOLPMSEL) Register.................................................
Device Configuration (DEVICECNF) Register .......................................................................
Part ID Register ..........................................................................................................
REVID Register ..........................................................................................................
Overview: Multiplexing of Interrupts Using the PIE Block ..........................................................
Typical PIE/CPU Interrupt Response - INTx.y .......................................................................
Reset Flow Diagram .....................................................................................................
PIE Interrupt Sources and External Interrupts XINT1/XINT2/XINT3 ..............................................
Multiplexed Interrupt Request Flow Diagram .........................................................................
PIECTRL Register (Address 0xCE0) ..................................................................................
PIE Interrupt Acknowledge Register (PIEACK) Register (Address 0xCE1) ......................................
PIEIFRx Register (x = 1 to 12) .........................................................................................
PIEIERx Register (x = 1 to 12) .........................................................................................
Interrupt Flag Register (IFR) — CPU Register ......................................................................
Interrupt Enable Register (IER) — CPU Register ...................................................................
Debug Interrupt Enable Register (DBGIER) — CPU Register ....................................................
External Interrupt n Control Register (XINTnCR) ...................................................................
External Interrupt n Counter (XINTnCTR) (Address 7078h) .......................................................
BOR Configuration (BORCFG) Register .............................................................................
List of Figures
90
90
91
91
92
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94
94
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96
97
98
98
106
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108
110
112
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115
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125
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128
130
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133
134
136
SPRUFN3D – January 2009 – Revised February 2013
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List of Tables
1
Flash/OTP Configuration Registers ..................................................................................... 16
2
Flash Options Register (FOPT) Field Descriptions ................................................................... 17
3
Flash Power Register (FPWR) Field Descriptions .................................................................... 17
4
Flash Status Register (FSTATUS) Field Descriptions ................................................................ 18
5
Flash Standby Wait Register (FSTDBYWAIT) Field Descriptions .................................................. 19
6
Flash Standby to Active Wait Counter Register (FACTIVEWAIT) Field Descriptions ............................ 19
7
Flash Wait-State Register (FBANKWAIT) Field Descriptions
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
.......................................................
OTP Wait-State Register (FOTPWAIT) Field Descriptions ..........................................................
Security Levels .............................................................................................................
Resources Affected by the CSM ........................................................................................
Resources Not Affected by the CSM ...................................................................................
Code Security Module (CSM) Registers ...............................................................................
CSM Status and Control Register (CSMSCR) Field Descriptions ..................................................
PLL, Clocking, Watchdog, and Low-Power Mode Registers ........................................................
Peripheral Clock Control 0 Register (PCLKCR0) Field Descriptions ...............................................
Peripheral Clock Control 1 Register (PCLKCR1) Field Descriptions ..............................................
Peripheral Clock Control 3 Register (PCLKCR3) Field Descriptions ...............................................
Low-Speed Peripheral Clock Prescaler Register (LOSPCP) Field Descriptions ..................................
Internal Oscillator n Trim (INTOSCnTRIM) Register Field Descriptions ...........................................
Clocking (XCLK) Field Descriptions .....................................................................................
Clock Control (CLKCTL) Register Field Descriptions .................................................................
Possible PLL Configuration Modes .....................................................................................
NMI Interrupt Registers ...................................................................................................
NMI Configuration (NMICFG) Register Bit Definitions (EALLOW) ..................................................
NMI Flag (NMIFLG) Register Bit Definitions (EALLOW Protected): ................................................
NMI Flag Clear (NMIFLGCLR) Register Bit Definitions (EALLOW Protected) ....................................
NMI Flag Force (NMIFLGFRC) Register Bit Definitions (EALLOW Protected): ...................................
NMI Watchdog Counter (NMIWDCNT) Register Bit Definitions .....................................................
NMI Watchdog Period () Register Bit Definitions (EALLOW Protected) ...........................................
PLL Settings ...............................................................................................................
PLL Status Register (PLLSTS) Field Descriptions ....................................................................
PLL Lock Period (PLLLOCKPRD) Register Field Descriptions .....................................................
Low-Power Mode Summary..............................................................................................
Low Power Modes .........................................................................................................
Low Power Mode Control 0 Register (LPMCR0) Field Descriptions ...............................................
Example Watchdog Key Sequences ....................................................................................
System Control and Status Register (SCSR) Field Descriptions ...................................................
Watchdog Counter Register (WDCNTR) Field Descriptions .........................................................
Watchdog Reset Key Register (WDKEY) Field Descriptions ........................................................
Watchdog Control Register (WDCR) Field Descriptions .............................................................
CPU-Timers 0, 1, 2 Configuration and Control Registers ............................................................
TIMERxTIM Register Field Descriptions ...............................................................................
TIMERxTIMH Register Field Descriptions .............................................................................
TIMERxPRD Register Field Descriptions ..............................................................................
TIMERxPRDH Register Field Descriptions ............................................................................
TIMERxTCR Register Field Descriptions...............................................................................
TIMERxTPR Register Field Descriptions ...............................................................................
SPRUFN3D – January 2009 – Revised February 2013
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List of Tables
20
21
22
24
24
25
26
31
32
33
34
35
37
38
38
41
45
45
46
46
46
46
47
50
50
52
53
53
54
57
59
60
60
60
63
63
64
64
64
64
65
5
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48
TIMERxTPRH Register Field Descriptions ............................................................................. 66
49
GPIO Control Registers................................................................................................... 72
50
GPIO Interrupt and Low Power Mode Select Registers .............................................................. 72
51
GPIO Data Registers
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
6
..................................................................................................... 74
Sampling Period ........................................................................................................... 77
Sampling Frequency ...................................................................................................... 77
Case 1: Three-Sample Sampling Window Width...................................................................... 77
Case 2: Six-Sample Sampling Window Width ......................................................................... 78
Default State of Peripheral Input ........................................................................................ 81
2802x GPIOA MUX ....................................................................................................... 82
2802x GPIOB MUX ....................................................................................................... 83
Analog MUX ................................................................................................................ 83
GPIO Port A Multiplexing 1 (GPAMUX1) Register Field Descriptions.............................................. 84
GPIO Port A MUX 2 (GPAMUX2) Register Field Descriptions ...................................................... 85
GPIO Port B MUX 1 (GPBMUX1) Register Field Descriptions ...................................................... 86
Analog I/O MUX (AIOMUX1) Register Field Descriptions ........................................................... 87
GPIO Port A Qualification Control (GPACTRL) Register Field Descriptions ...................................... 88
GPIO Port B Qualification Control (GPBCTRL) Register Field Descriptions ...................................... 89
GPIO Port A Qualification Select 1 (GPAQSEL1) Register Field Descriptions ................................... 90
GPIO Port A Qualification Select 2 (GPAQSEL2) Register Field Descriptions ................................... 90
GPIO Port B Qualification Select 1 (GPBQSEL1) Register Field Descriptions ................................... 91
GPIO Port A Direction (GPADIR) Register Field Descriptions ...................................................... 91
GPIO Port B Direction (GPBDIR) Register Field Descriptions ...................................................... 92
Analog I/O DIR (AIODIR) Register Field Descriptions ................................................................ 92
GPIO Port A Internal Pullup Disable (GPAPUD) Register Field Descriptions ..................................... 93
GPIO Port B Internal Pullup Disable (GPBPUD) Register Field Descriptions ..................................... 93
GPIO Port A Data (GPADAT) Register Field Descriptions .......................................................... 94
GPIO Port B Data (GPBDAT) Register Field Descriptions .......................................................... 94
Analog I/O DAT (AIODAT) Register Field Descriptions .............................................................. 95
GPIO Port A Set (GPASET) Register Field Descriptions ............................................................ 95
GPIO Port A Clear (GPACLEAR) Register Field Descriptions ...................................................... 96
GPIO Port A Toggle (GPATOGGLE) Register Field Descriptions .................................................. 96
GPIO Port B Set (GPBSET) Register Field Descriptions ............................................................ 96
GPIO Port B Clear (GPBCLEAR) Register Field Descriptions ...................................................... 96
GPIO Port B Toggle (GPBTOGGLE) Register Field Descriptions .................................................. 97
Analog I/O Set (AIOSET) Register Field Descriptions ................................................................ 97
Analog I/O Clear (AIOCLEAR) Register Field Descriptions ......................................................... 97
Analog I/O Toggle (AIOTOGGLE) Register Field Descriptions ..................................................... 97
GPIO XINTn Interrupt Select (GPIOXINTnSEL) Register Field Descriptions ..................................... 98
XINT1/XINT2/XINT3 Interrupt Select and Configuration Registers ................................................. 98
GPIO Low Power Mode Wakeup Select (GPIOLPMSEL) Register Field Descriptions .......................... 99
Peripheral Frame 0 Registers ......................................................................................... 100
Peripheral Frame 1 Registers .......................................................................................... 101
Peripheral Frame 2 Registers .......................................................................................... 101
Access to EALLOW-Protected Registers ............................................................................. 102
EALLOW-Protected Device Emulation Registers .................................................................... 102
EALLOW-Protected Flash/OTP Configuration Registers ........................................................... 102
EALLOW-Protected Code Security Module (CSM) Registers ..................................................... 103
EALLOW-Protected PLL, Clocking, Watchdog, and Low-Power Mode Registers .............................. 103
List of Tables
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97
EALLOW-Protected GPIO Registers .................................................................................. 104
98
EALLOW-Protected PIE Vector Table
99
EALLOW-Protected ePWM1 - ePWM4 Registers ................................................................... 105
100
Device Emulation Registers ............................................................................................ 106
101
DEVICECNF Register Field Descriptions ............................................................................. 106
102
PARTID Register Field Descriptions
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
................................................................................
..................................................................................
CLASSID Register Field Descriptions .................................................................................
REVID Register Field Descriptions ....................................................................................
Enabling Interrupt ........................................................................................................
Interrupt Vector Table Mapping .......................................................................................
Vector Table Mapping After Reset Operation .......................................................................
PIE MUXed Peripheral Interrupt Vector Table .......................................................................
PIE Vector Table .........................................................................................................
PIE Configuration and Control Registers .............................................................................
PIECTRL Register Address Field Descriptions ......................................................................
PIE Interrupt Acknowledge Register (PIEACK) Field Descriptions ................................................
PIEIFRx Register Field Descriptions ..................................................................................
PIEIERx Register (x = 1 to 12) Field Descriptions...................................................................
Interrupt Flag Register (IFR) — CPU Register Field Descriptions ................................................
Interrupt Enable Register (IER) — CPU Register Field Descriptions .............................................
Debug Interrupt Enable Register (DBGIER) — CPU Register Field Descriptions ..............................
Interrupt Control and Counter Registers (not EALLOW Protected) ...............................................
External Interrupt n Control Register (XINTnCR) Field Descriptions..............................................
External Interrupt n Counter (XINTnCTR) Field Descriptions ......................................................
BOR Configuration (BORCFG) Field Descriptions ..................................................................
Revisions to this Document .............................................................................................
SPRUFN3D – January 2009 – Revised February 2013
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List of Tables
105
107
107
108
112
113
113
119
120
124
125
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137
7
Preface
SPRUFN3D – January 2009 – Revised February 2013
Read This First
About This Manual
This reference guide is applicable for the Systems Control and Interrupts found on the TMS320x2802x
Piccolo™ microcontrollers (MCUs).
This guide describes how various system controls and interrupts work. It includes information on the:
• Flash and one-time programmable (OTP) memories
• Code security module (CSM), which is a security feature incorporated in TMS320x28x™ devices.
• Clocking mechanisms including the oscillator, PLL, XCLKOUT, watchdog module, and the low-power
modes. In addition, the 32-bit CPU-Timers are also described.
• GPIO multiplexing (MUX) registers used to select the operation of shared pins on the device.
• Accessing the peripheral frames to write to and read from various peripheral registers on the device.
• Interrupt sources both external and the peripheral interrupt expansion (PIE) block that multiplexes
numerous interrupt sources into a smaller set of interrupt inputs.
Notational Conventions
This document uses the following conventions.
• Hexadecimal numbers are shown with the suffix h or with a leading 0x. For example, the following
number is 40 hexadecimal (decimal 64): 40h or 0x40.
• Registers in this document are shown in figures and described in tables.
– Each register figure shows a rectangle divided into fields that represent the fields of the register.
Each field is labeled with its bit name, its beginning and ending bit numbers above, and its
read/write properties below. A legend explains the notation used for the properties.
– Reserved bits in a register figure designate a bit that is used for future device expansion.
Related Documentation From Texas Instruments
The following books describe the TMS320F2802x and related support tools that are available on the TI
website:
SPRS523 — TMS320F28020, TMS320F28021, TMS320F28022, TMS320F28023, TMS320F28026,
TMS320F28027 Piccolo Microcontrollers Data Manual contains the pinout, signal descriptions,
as well as electrical and timing specifications for the 2802x devices.
SPRZ292 — TMS320F28020, TMS320F28021, TMS320F28022, TMS320F28023, TMS320F28026,
TMS320F28027 Piccolo MCU Silicon Errata describes known advisories on silicon and provides
workarounds.
CPU User's Guides—
SPRU430 — TMS320C28x CPU and Instruction Set Reference Guide describes the central processing
unit (CPU) and the assembly language instructions of the TMS320C28x fixed-point digital signal
processors (DSPs). It also describes emulation features available on these DSPs.
Peripheral Guides—
SPRUFN3 — TMS320F2802x/TMS320F2802xx Piccolo System Control and Interrupts Reference
Guide describes the various interrupts and system control features of the 2802x microcontrollers
(MCUs).
8
Preface
SPRUFN3D – January 2009 – Revised February 2013
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Related Documentation From Texas Instruments
www.ti.com
SPRU566 — TMS320x28xx, 28xxx DSP Peripheral Reference Guide describes the peripheral
reference guides of the 28x digital signal processors (DSPs).
SPRUFN6 — TMS320x2802x Piccolo Boot ROM Reference Guide describes the purpose and features
of the boot loader (factory-programmed boot-loading software) and provides examples of code. It
also describes other contents of the device on-chip boot ROM and identifies where all of the
information is located within that memory.
SPRUGE5 — TMS320x2802x, 2803x Piccolo Analog-to-Digital Converter (ADC) and Comparator
Reference Guide describes how to configure and use the on-chip ADC module, which is a 12-bit
pipelined ADC.
SPRUGE9 — TMS320x2802x, 2803x Piccolo Enhanced Pulse Width Modulator (ePWM) Module
Reference Guide describes the main areas of the enhanced pulse width modulator that include
digital motor control, switch mode power supply control, UPS (uninterruptible power supplies), and
other forms of power conversion.
SPRUGE8 — TMS320x2802x, 2803x Piccolo High-Resolution Pulse Width Modulator (HRPWM)
describes the operation of the high-resolution extension to the pulse width modulator (HRPWM).
SPRUGH1 — TMS320x2802x, 2803x Piccolo Serial Communications Interface (SCI) Reference
Guide describes how to use the SCI.
SPRUFZ8 — TMS320x2802x, 2803x Piccolo Enhanced Capture (eCAP) Module Reference Guide
describes the enhanced capture module. It includes the module description and registers.
SPRUG71 — TMS320x2802x, 2803x Piccolo Serial Peripheral Interface (SPI) Reference Guide
describes the SPI - a high-speed synchronous serial input/output (I/O) port - that allows a serial bit
stream of programmed length (one to sixteen bits) to be shifted into and out of the device at a
programmed bit-transfer rate.
SPRUFZ9 — TMS320x2802x, 2803x Piccolo Inter-Integrated Circuit (I2C) Reference Guide describes
the features and operation of the inter-integrated circuit (I2C) module.
Tools Guides—
SPRU513 — TMS320C28x Assembly Language Tools v5.0.0 User's Guide describes the assembly
language tools (assembler and other tools used to develop assembly language code), assembler
directives, macros, common object file format, and symbolic debugging directives for the
TMS320C28x device.
SPRU514 — TMS320C28x Optimizing C/C++ Compiler v5.0.0 User's Guide describes the
TMS320C28x™ C/C++ compiler. This compiler accepts ANSI standard C/C++ source code and
produces TMS320 DSP assembly language source code for the TMS320C28x device.
SPRU608 — TMS320C28x Instruction Set Simulator Technical Overview describes the simulator,
available within the Code Composer Studio for TMS320C2000 IDE, that simulates the instruction
set of the C28x™ core.
Piccolo, TMS320x28x, TMS320C28x, C28x, Code Composer Studio are trademarks of Texas Instruments.
SPRUFN3D – January 2009 – Revised February 2013
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Read This First
9
Reference Guide
SPRUFN3D – January 2009 – Revised February 2013
System Control
This chapter describes the proper sequence to configure the wait states and operating mode of flash and
one-time programmable (OTP) memories. It also includes information on flash and OTP power modes and
how to improve flash performance by enabling the flash pipeline mode.
1
Flash and OTP Memory
This section describes how to configure flash and one-time programmable (OTP) memory.
1.1
Flash Memory
The on-chip flash is uniformly mapped in both program and data memory space. This flash memory is
always enabled and features:
• Multiple sectors
The minimum amount of flash memory that can be erased is a sector. Having multiple sectors provides
the option of leaving some sectors programmed and only erasing specific sectors.
• Code security
The flash is protected by the Code Security Module (CSM). By programming a password into the flash,
the user can prevent access to the flash by unauthorized persons. See Section 2 for information in
using the Code Security Module.
• Low power modes
To save power when the flash is not in use, two levels of low power modes are available. See
Section 1.3 for more information on the available flash power modes.
• Configurable wait states
Configurable wait states can be adjusted based on CPU frequency to give the best performance for a
given execution speed.
• Enhanced performance
A flash pipeline mode is provided to improve performance of linear code execution.
1.2
OTP Memory
The 1K x 16 block of one-time programmable (OTP) memory is uniformly mapped in both program and
data memory space. Thus, the OTP can be used to program data or code. This block, unlike flash, can be
programmed only one time and cannot be erased.
10
System Control
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1.3
Flash and OTP Power Modes
The following operating states apply to the flash and OTP memory:
• Reset or Sleep State
This is the state after a device reset. In this state, the bank and pump are in a sleep state (lowest
power). When the flash is in the sleep state, a CPU data read or opcode fetch to the flash or OTP
memory map area will automatically initiate a change in power modes to the standby state and then to
the active state. During this transition time to the active state, the CPU will automatically be stalled.
Once the transition to the active state is completed, the CPU access will complete as normal.
• Standby State
In this state, the bank and pump are in standby power mode state. This state uses more power then
the sleep state, but takes a shorter time to transition to the active or read state. When the flash is in
the standby state, a CPU data read or opcode fetch to the flash or OTP memory map area will
automatically initiate a change in power modes to the active state. During this transition time to the
active state, the CPU will automatically be stalled. Once the flash/OTP has reached the active state,
the CPU access will complete as normal.
• Active or Read State
In this state, the bank and pump are in active power mode state (highest power). The CPU read or
fetch access wait states to the flash/OTP memory map area is controlled by the FBANKWAIT and
FOTPWAIT registers. A prefetch mechanism called flash pipeline can also be enabled to improve fetch
performance for linear code execution.
NOTE: During the boot process, the Boot ROM performs a dummy read of the Code Security
Module (CSM) password locations located in the flash. This read is performed to unlock a
new or erased device that has no password stored in it so that flash programming or loading
of code into CSM protected SARAM can be performed. On devices with a password stored,
this read has no affect and the CSM remains locked (see Section 2 for information on the
CSM). One effect of this read is that the flash will transition from the sleep (reset) state to the
active state.
The flash/OTP bank and pump are always in the same power mode. See Figure 1 for a graphic depiction
of the available power states. You can change the current flash/OTP memory power state as follows:
• To move to a lower power state
Change the PWR mode bits from a higher power mode to a lower power mode. This change
instantaneously moves the flash/OTP bank to the lower power state. This register should be accessed
only by code running outside the flash/OTP memory.
• To move to a higher power state
To move from a lower power state to a higher power state, there are two options.
1. Change the FPWR register from a lower state to a higher state. This access brings the flash/OTP
memory to the higher state.
2. Access the flash or OTP memory by a read access or program opcode fetch access. This access
automatically brings the flash/OTP memory to the active state.
There is a delay when moving from a lower power state to a higher one. See Figure 1. This delay is
required to allow the flash to stabilize at the higher power mode. If any access to the flash/OTP memory
occurs during this delay the CPU automatically stalls until the delay is complete.
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Figure 1. Flash Power Mode State Diagram
Highest
power
Active
state
Delay
FACTIVEWAIT
cycles
PWR=0,1
PWR=0,0
Standby
state
PWR=1,1
or access to
the Flash/OTP
Delay
FSTDBYWAIT
cycles
PWR=0,0
Delay
FACTIVEWAIT
cycles
Delay
FSTDBYWAIT
cycles
PWR=0,1
Sleep
state
Lowest power
Longest
Wake up time
PWR=1,1
or access to
the Flash/OTP
Reset
The duration of the delay is determined by the FSTDBYWAIT and FACTIVEWAIT registers. Moving from
the sleep state to a standby state is delayed by a count determined by the FSTDBYWAIT register. Moving
from the standby state to the active state is delayed by a count determined by the FACTIVEWAIT register.
Moving from the sleep mode (lowest power) to the active mode (highest power) is delayed by
FSTDBYWAIT + FACTIVEWAIT. These registers should be left in their default state.
1.3.1
Flash and OTP Performance
CPU read or data fetch operations to the flash/OTP can take one of the following forms:
• 32-bit instruction fetch
• 16-bit or 32-bit data space read
• 16-bit program space read
Once flash is in the active power state, then a read or fetch access to the bank memory map area can be
classified as a flash access or an OTP access.
The main flash array is organized into rows and columns. The rows contain 2048 bits of information.
Accesses to flash and OTP are one of three types:
1. Flash Memory Random Access
The first access to a 2048 bit row is considered a random access.
2. Flash Memory Paged Access
While the first access to a row is considered a random access, subsequent accesses within the same
row are termed paged accesses.
The number of wait states for both a random and a paged access can be configured by programming
the FBANKWAIT register. The number of wait states used by a random access is controlled by the
RANDWAIT bits and the number of wait states used by a paged access is controlled by the
PAGEWAIT bits. The FBANKWAIT register defaults to a worst-case wait state count and, thus, needs
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to be initialized for the appropriate number of wait states to improve performance based on the CPU
clock rate and the access time of the flash. The flash supports 0-wait accesses when the PAGEWAIT
bits are set to zero. This assumes that the CPU speed is low enough to accommodate the access
time. To determine the random and paged access time requirements, refer to the Data Manual for your
particular device.
3. OTP Access
Read or fetch accesses to the OTP are controlled by the OTPWAIT bits in the FOTPWAIT register.
Accesses to the OTP take longer than the flash and there is no paged mode. To determine OTP
access time requirements, see the data manual for your particular device.
Some other points to keep in mind when working with flash:
• CPU writes to the flash or OTP memory map area are ignored. They complete in a single cycle.
• When the Code Security Module (CSM) is secured, reads to the flash/OTP memory map area from
outside the secure zone take the same number of cycles as a normal access. However, the read
operation returns a zero.
• Reads of the CSM password locations are hardwired for 16 wait-states. The PAGEWAIT and
RANDOMWAIT bits have no effect on these locations. See Section 2 for more information on the CSM.
1.3.2
Flash Pipeline Mode
Flash memory is typically used to store application code. During code execution, instructions are fetched
from sequential memory addresses, except when a discontinuity occurs. Usually the portion of the code
that resides in sequential addresses makes up the majority of the application code and is referred to as
linear code. To improve the performance of linear code execution, a flash pipeline mode has been
implemented. The flash pipeline feature is disabled by default. Setting the ENPIPE bit in the FOPT register
enables this mode. The flash pipeline mode is independent of the CPU pipeline.
An instruction fetch from the flash or OTP reads out 64 bits per access. The starting address of the access
from flash is automatically aligned to a 64-bit boundary such that the instruction location is within the 64
bits to be fetched. With flash pipeline mode enabled (see Figure 2), the 64 bits read from the instruction
fetch are stored in a 64-bit wide by 2-level deep instruction prefetch buffer. The contents of this prefetch
buffer are then sent to the CPU for processing as required.
Up to two 32-bit instructions or up to four 16-bit instructions can reside within a single 64-bit access. The
majority of C28x instructions are 16 bits, so for every 64-bit instruction fetch from the flash bank it is likely
that there are up to four instructions in the prefetch buffer ready to process through the CPU. During the
time it takes to process these instructions, the flash pipeline automatically initiates another access to the
flash bank to prefetch the next 64 bits. In this manner, the flash pipeline mode works in the background to
keep the instruction prefetch buffers as full as possible. Using this technique, the overall efficiency of
sequential code execution from flash or OTP is improved significantly.
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Figure 2. Flash Pipeline
Flash and OTP
16 bits
Flash Pipeline
Instruction buffer
Instruction Fetch
CPU
32 bits
64-bit
Buffer
64-bit
Buffer
Flash or OTP
Read
(64 bits)
M
U
X
Data read from either program or data memory
The flash pipeline prefetch is aborted only on a PC discontinuity caused by executing an instruction such
as a branch, BANZ, call, or loop. When this occurs, the prefetch is aborted and the contents of the
prefetch buffer are flushed. There are two possible scenarios when this occurs:
1. If the destination address is within the flash or OTP, the prefetch aborts and then resumes at the
destination address.
2. If the destination address is outside of the flash and OTP, the prefetch is aborted and begins again
only when a branch is made back into the flash or OTP. The flash pipeline prefetch mechanism only
applies to instruction fetches from program space. Data reads from data memory and from program
memory do not utilize the prefetch buffer capability and thus bypass the prefetch buffer. For example,
instructions such as MAC, DMAC, and PREAD read a data value from program memory. When this
read happens, the prefetch buffer is bypassed but the buffer is not flushed. If an instruction prefetch is
already in progress when a data read operation is initiated, then the data read will be stalled until the
prefetch completes.
1.3.3
Reserved Locations Within Flash and OTP
When allocating code and data to flash and OTP memory, keep the following in mind:
1. Address locations 0x3F 7FF6 and 0x3F 7FF7 are reserved for an entry into flash branch instruction.
When the boot to flash boot option is used, the boot ROM will jump to address 0x3F 7FF6. If you
program a branch instruction here that will then redirect code execution to the entry point of the
application.
2. For code security operation, all addresses between 0x3F 7F80 and 0x3F 7FF5 cannot be used for
program code or data, but must be programmed to 0x0000 when the Code Security Password is
programmed. If security is not a concern, then these addresses 0x3F 7F80 through 0x3F 7FF5 may be
used for code or data. See Section 2 for information in using the Code Security Module.
3. Addresses from 0x3F 7FF0 to 0x3F 7FF5 are reserved for data variables and should not contain
program code.
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1.3.4
Procedure to Change the Flash Configuration Registers
During flash configuration, no accesses to the flash or OTP can be in progress. This includes instructions
still in the CPU pipeline, data reads, and instruction prefetch operations. To be sure that no access takes
place during the configuration change, you should follow the procedure shown in Figure 3 for any code
that modifies the FOPT, FPWR, FBANKWAIT, or FOTPWAIT registers.
Figure 3. Flash Configuration Access Flow Diagram
SARAM, Flash, OTP
Branch or call to
configuration code
Begin Flash configuration
change
Branch or call is required to properly flush the
CPU pipeline before the configuration
change.
The function that changes the configuration
cannot execute from the Flash or OTP.
SARAM
Do not execute from
Flash/OTP
Flash configuration
change
Wait 8 cycles (8 NOPs)
Write instructions to FOPT, FBANKWAIT,
etc.
Wait eight cycles to let the write instructions
propagate through the CPU pipeline. This
must be done before the return-from-function
call is made.
Return to calling function
SARAM, Flash,
or OTP
Continue execution
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Flash and OTP Registers
The flash and OTP memory can be configured by the registers shown in Table 1. The configuration
registers are all EALLOW protected. The bit descriptions are in Figure 4 through Figure 10.
Table 1. Flash/OTP Configuration Registers
Name
(1) (2)
Address
Size (x16)
Description
Bit Description
FOPT
0x0A80
1
Flash Option Register
Figure 4
Reserved
0x0A81
1
Reserved
FPWR
0x0A82
1
Flash Power Modes Register
Figure 5
FSTATUS
0x0A83
1
Status Register
Figure 6
0x0A84
1
Flash Sleep To Standby Wait Register
Figure 7
0x0A85
1
Flash Standby To Active Wait Register
Figure 8
FBANKWAIT
0x0A86
1
Flash Read Access Wait State Register
Figure 9
FOTPWAIT
0x0A87
1
OTP Read Access Wait State Register
Figure 10
FSTDBYWAIT
FACTIVEWAIT
(1)
(2)
(3)
(3)
(3)
These registers are EALLOW protected. See Section 5.2 for information.
These registers are protected by the Code Security Module (CSM). See Section 2 for more information.
These registers should be left in their default state.
NOTE: The flash configuration registers should not be written to by code that is running from OTP or
flash memory or while an access to flash or OTP may be in progress. All register accesses
to the flash registers should be made from code executing outside of flash/OTP memory and
an access should not be attempted until all activity on the flash/OTP has completed. No
hardware is included to protect against this.
To summarize, you can read the flash registers from code executing in flash/OTP; however,
do not write to the registers.
CPU write access to the flash configuration registers can be enabled only by executing the EALLOW
instruction. Write access is disabled when the EDIS instruction is executed. This protects the registers
from spurious accesses. Read access is always available. The registers can be accessed through the
JTAG port without the need to execute EALLOW. See Section 5.2 for information on EALLOW protection.
These registers support both 16-bit and 32-bit accesses.
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Figure 4. Flash Options Register (FOPT)
15
1
0
Reserved
ENPIPE
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 2. Flash Options Register (FOPT) Field Descriptions
Bit
15-1
0
Field
Value
Description
(1) (2) (3)
Reserved
Any writes to these bit(s) must always have a value of 0.
ENPIPE
Enable Flash Pipeline Mode Bit. Flash pipeline mode is active when this bit is set. The pipeline
mode improves performance of instruction fetches by prefetching instructions. See Section 1.3.2 for
more information.
When pipeline mode is enabled, the flash wait states (paged and random) must be greater than
zero.
On flash devices, ENPIPE affects fetches from flash and OTP.
(1)
(2)
(3)
0
Flash Pipeline mode is not active. (default)
1
Flash Pipeline mode is active.
This register is EALLOW protected. See Section 5.2 for more information.
This register is protected by the Code Security Module (CSM). See Section 2 for more information.
When writing to this register, follow the procedure described in Section 1.3.4.
Figure 5. Flash Power Register (FPWR)
15
2
1
0
Reserved
PWR
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 3. Flash Power Register (FPWR) Field Descriptions
Bit
(1)
(2)
Field
Value
Description
(1) (2)
15-2
Reserved
Any writes to these bit(s) must always have a value of 0.
1-0
PWR
Flash Power Mode Bits. Writing to these bits changes the current power mode of the flash bank
and pump. See section Section 1.3 for more information on changing the flash bank power mode.
00
Pump and bank sleep (lowest power)
01
Pump and bank standby
10
Reserved (no effect)
11
Pump and bank active (highest power)
This register is EALLOW protected. See Section 5.2 for more information.
This register is protected by the Code Security Module (CSM). See Section 2 for more information.
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Figure 6. Flash Status Register (FSTATUS)
15
9
7
8
Reserved
3VSTAT
R-0
R/W1C-0
3
2
Reserved
4
ACTIVEWAITS
STDBYWAITS
1
PWRS
0
R-0
R-0
R-0
R-0
LEGEND: R/W = Read/Write; R = Read only; W1C = Write 1 to clear; -n = value after reset
Table 4. Flash Status Register (FSTATUS) Field Descriptions
Bit
Field
Value
Description
(1) (2)
15-9
Reserved
Any writes to these bit(s) must always have a value of 0.
8
3VSTAT
Flash Voltage (VDD3VFL) Status Latch Bit. When set, this bit indicates that the 3VSTAT signal from
the pump module went to a high level. This signal indicates that the flash 3.3-V supply went out of
the allowable range.
0
Writes of 0 are ignored.
1
When this bit reads 1, it indicates that the flash 3.3-V supply went out of the allowable range.
Clear this bit by writing a 1.
7-4
3
2
1-0
Reserved
Any writes to these bit(s) must always have a value of 0.
ACTIVEWAITS
Bank and Pump Standby To Active Wait Counter Status Bit. This bit indicates whether the
respective wait counter is timing out an access.
0
The counter is not counting.
1
The counter is counting.
STDBYWAITS
Bank and Pump Sleep To Standby Wait Counter Status Bit. This bit indicates whether the
respective wait counter is timing out an access.
0
The counter is not counting.
1
The counter is counting.
PWRS
Power M odes Status Bits. These bits indicate which power mode the flash/OTP is currently in.
The PWRS bits are set to the new power mode only after the appropriate timing delays have
expired.
(1)
(2)
18
00
Pump and bank in sleep mode (lowest power)
01
Pump and bank in standby mode
10
Reserved
11
Pump and bank active and in read mode (highest power)
This register is EALLOW protected. See Section 5.2 for more information.
This register is protected by the Code Security Module (CSM). See Section 2 for more information.
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Figure 7. Flash Standby Wait Register (FSTDBYWAIT)
15
9
8
0
Reserved
STDBYWAIT
R-0
R/W-0x1FF
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 5. Flash Standby Wait Register (FSTDBYWAIT) Field Descriptions
Bit
Field
Value
Description
(1) (2)
15-9
Reserved
Any writes to these bit(s) must always have a value of 0.
8-0
STDBYWAIT
This register should be left in its default state.
Bank and Pump Sleep To Standby Wait Count.
111111111
(1)
(2)
511 SYSCLKOUT cycles (default)
This register is EALLOW protected. See Section 5.2 for more information.
This register is protected by the Code Security Module (CSM). See Section 2 for more information.
Figure 8. Flash Standby to Active Wait Counter Register (FACTIVEWAIT)
7
9
8
0
Reserved
ACTIVEWAIT
R-0
R/W-0x1FF
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 6. Flash Standby to Active Wait Counter Register (FACTIVEWAIT) Field Descriptions
Bits
Field
Value
Description
(1) (2)
15-9
Reserved
Any writes to these bit(s) must always have a value of 0.
8-0
ACTIVEWAIT
This register should be left in its default state.
Bank and Pump Standby To Active Wait Count:
111111111
(1)
(2)
511 SYSCLKOUT cycles (default)
This register is EALLOW protected. See Section 5.2 for more information.
This register is protected by the Code Security Module (CSM). See Section 2 for more information.
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Figure 9. Flash Wait-State Register (FBANKWAIT)
15
12
11
8
7
4
3
0
Reserved
PAGEWAIT
Reserved
RANDWAIT
R-0
R/W-0xF
R-0
R/W-0xF
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 7. Flash Wait-State Register (FBANKWAIT) Field Descriptions
Bits
Field
Value
Description
(1) (2) (3)
15-12 Reserved
Any writes to these bit(s) must always have a value of 0.
11-8
Flash Paged Read Wait States. These register bits specify the number of wait states for a paged
read operation in CPU clock cycles (0..15 SYSCLKOUT cycles) to the flash bank. See Section 1.3.1
for more information.
PAGEWAIT
See the device-specific data manual for the minimum time required for a PAGED flash access.
You must set RANDWAIT to a value greater than or equal to the PAGEWAIT setting. No hardware is
provided to detect a PAGEWAIT value that is greater then RANDWAIT.
0000
Zero wait-state per paged flash access or one SYSCLKOUT cycle per access
0001
One wait state per paged flash access or a total of two SYSCLKOUT cycles per access
0010
Two wait states per paged flash access or a total of three SYSCLKOUT cycles per access
0011
Three wait states per paged flash access or a total of four SYSCLKOUT cycles per access
...
1111
...
15 wait states per paged flash access or a total of 16 SYSCLKOUT cycles per access. (default)
7-4
Reserved
Any writes to these bit(s) must always have a value of 0.
3-0
RANDWAIT
Flash Random Read Wait States. These register bits specify the number of wait states for a random
read operation in CPU clock cycles (1..15 SYSCLKOUT cycles) to the flash bank. See Section 1.3.1
for more information.
See the device-specific data manual for the minimum time required for a RANDOM flash access.
RANDWAIT must be set greater than 0. That is, at least 1 random wait state must be used. In
addition, you must set RANDWAIT to a value greater than or equal to the PAGEWAIT setting. The
device will not detect and correct a PAGEWAIT value that is greater then RANDWAIT.
0000
Illegal value. RANDWAIT must be set greater then 0.
0001
One wait state per random flash access or a total of two SYSCLKOUT cycles per access.
0010
Two wait states per random flash access or a total of three SYSCLKOUT cycles per access.
0011
Three wait states per random flash access or a total of four SYSCLKOUT cycles per access.
...
1111
(1)
(2)
(3)
20
...
15 wait states per random flash access or a total of 16 SYSCLKOUT cycles per access. (default)
This register is EALLOW protected. See Section 5.2 for more information.
This register is protected by the Code Security Module (CSM). See Section 2 for more information.
When writing to this register, follow the procedure described in Section 1.3.4.
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Figure 10. OTP Wait-State Register (FOTPWAIT)
15
5
4
0
Reserved
OTPWAIT
R-0
R/W-0x1F
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 8. OTP Wait-State Register (FOTPWAIT) Field Descriptions
Bits
Field
Value
Description
(1) (2) (3)
15-5
Reserved
Any writes to these bit(s) must always have a value of 0.
4-0
OTPWAIT
OTP Read Wait States. These register bits specify the number of wait states for a read operation in
CPU clock cycles (1..31 SYSCLKOUT cycles) to the OTP. See CPU Read Or Fetch Access From
flash/OTP section for details. There is no PAGE mode in the OTP.
OTPWAIT must be set greater than 0. That is, a minimum of 1 wait state must be used. See the
device-specific data manual for the minimum time required for an OTP access.
00000 Illegal value. OTPWAIT must be set to 1 or greater.
00001 One wait state will be used each OTP access for a total of two SYSCLKOUT cycles per access.
00010 Two wait states will be used for each OTP access for a total of three SYSCLKOUT cycles per access.
00011 Three wait states will be used for each OTP access for a total of four SYSCLKOUT cycles per access.
...
...
11111 31 wait states will be used for an OTP access for a total of 32 SYSCLKOUT cycles per access.
(1)
(2)
(3)
This register is EALLOW protected. See Section 5.2 for more information.
This register is protected by the Code Security Module (CSM). See Section 2 for more information.
When writing to this register, follow the procedure described in Section 1.3.4.
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Code Security Module (CSM)
The code security module (CSM) is a security feature incorporated in 28x devices. It prevents
access/visibility to on-chip memory to unauthorized persons—that is, it prevents duplication/reverse
engineering of proprietary code.
The word secure means access to on-chip memory is protected. The word unsecure means access to onchip secure memory is not protected — that is, the contents of the memory could be read by any means
(through a debugging tool such as Code Composer Studio™, for example).
2.1
Functional Description
The security module restricts the CPU access to certain on-chip memory without interrupting or stalling
CPU execution. When a read occurs to a protected memory location, the read returns a zero value and
CPU execution continues with the next instruction. This, in effect, blocks read and write access to various
memories through the JTAG port or external peripherals. Security is defined with respect to the access of
on-chip memory and prevents unauthorized copying of proprietary code or data.
The device is secure when CPU access to the on-chip secure memory locations is restricted. When
secure, two levels of protection are possible, depending on where the program counter is currently
pointing. If code is currently running from inside secure memory, only an access through JTAG is blocked
(that is, through the emulator). This allows secure code to access secure data. Conversely, if code is
running from nonsecure memory, all accesses to secure memories are blocked. User code can
dynamically jump in and out of secure memory, thereby allowing secure function calls from nonsecure
memory. Similarly, interrupt service routines can be placed in secure memory, even if the main program
loop is run from nonsecure memory.
Security is protected by a password of 128-bits of data (eight 16-bit words) that is used to secure or
unsecure the device. This password is stored at the end of flash in 8 words referred to as the password
locations.
The device is unsecured by executing the password match flow (PMF), described in Section 2.3.2. Table 9
shows the levels of security.
Table 9. Security Levels
PMF Executed
With Correct
Password?
Operating Mode
Program Fetch
Location
Security Description
No
Secure
Outside secure memory
No
Secure
Inside secure memory
CPU has full access.
JTAG port cannot read the secured memory contents.
Yes
Not Secure
Anywhere
Full access for CPU and JTAG port to secure memory
Only instruction fetches by the CPU are allowed to secure
memory. In other words, code can still be executed, but not
read
The password is stored in code security password locations (PWL) in flash memory (0x3F 7FF8 0x3F 7FFF). These locations store the password predetermined by the system designer.
If the password locations have all 128 bits as ones, the device is labeled unsecure. Since new flash
devices have erased flash (all ones), only a read of the password locations is required to bring the device
into unsecure mode. If the password locations have all 128 bits as zeros, the device is secure, regardless
of the contents of the KEY registers. Do not use all zeros as a password or reset the device during an
erase of the flash. Resetting the device during an erase routine can result in either an all zero or unknown
password. If a device is reset when the password locations are all zeros, the device cannot be unlocked
by the password match flow described in Section 2.3.2. Using a password of all zeros will seriously limit
your ability to debug secure code or reprogram the flash.
NOTE: If a device is reset while the password locations are all zero or an unknown value, the device
will be permanently locked unless a method to run the flash erase routine from secure
SARAM is embedded into the flash or OTP. Care must be taken when implementing this
procedure to avoid introducing a security hole.
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User accessible registers (eight 16-bit words) that are used to unsecure the device are referred to as key
registers. These registers are mapped in the memory space at addresses 0x00 0AE0 - 0x00 0AE7 and
are EALLOW protected.
In addition to the CSM, the emulation code security logic (ECSL) has been implemented to prevent
unauthorized users from stepping through secure code. Any code or data access to flash, user OTP, L0
memory while the emulator is connected will trip the ECSL and break the emulation connection. To allow
emulation of secure code, while maintaining the CSM protection against secure memory reads, you must
write the correct value into the lower 64 bits of the KEY register, which matches the value stored in the
lower 64 bits of the password locations within the flash. Note that dummy reads of all 128 bits of the
password in the flash must still be performed. If the lower 64 bits of the password locations are all ones
(unprogrammed), then the KEY value does not need to match.
When initially debugging a device with the password locations in flash programmed (that is, secured), the
emulator takes some time to take control of the CPU. During this time, the CPU will start running and may
execute an instruction that performs an access to a protected ECSL area. If this happens, the ECSL will
trip and cause the emulator connection to be cut. Two solutions to this problem exist:
1. The first is to use the Wait-In-Reset emulation mode, which will hold the device in reset until the
emulator takes control. The emulator must support this mode for this option.
2. The second option is to use the “Branch to check boot mode” boot option. This will sit in a loop and
continuously poll the boot mode select pins. You can select this boot mode and then exit this mode
once the emulator is connected by re-mapping the PC to another address or by changing the boot
mode selection pin to the desired boot mode.
NOTE:
Reserved Flash Locations When Using Code Security
For code security operation, all addresses between 0x3F 7F80 and 0x3F 7FF5 cannot be
used as program code or data, but must be programmed to 0x0000 when the Code
Security Password is programmed. If security is not a concern, then these addresses may be
used for code or data. The 128-bit password (at 0x3F 7FF8 - 0x3F 7FFF) must not be
programmed to zeros. Doing so would permanently lock the device.
Addresses 0x3F 7FF0 through 0x3F 7FF5 are reserved for data variables and should not
contain program code.
Disclaimer:
Code Security Module Disclaimer
The Code Security Module ( CSM ) included on this device was designed to password
protect the data stored in the associated memory and is warranted by Texas Instruments
(TI), in accordance with its standard terms and conditions, to conform to TI's published
specifications for the warranty period applicable for this device.
TI DOES NOT, HOWEVER, WARRANT OR REPRESENT THAT THE CSM CANNOT BE
COMPROMISED OR BREACHED OR THAT THE DATA STORED IN THE ASSOCIATED
MEMORY CANNOT BE ACCESSED THROUGH OTHER MEANS. MOREOVER, EXCEPT
AS SET FORTH ABOVE, TI MAKES NO WARRANTIES OR REPRESENTATIONS
CONCERNING THE CSM OR OPERATION OF THIS DEVICE, INCLUDING ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
IN NO EVENT SHALL TI BE LIABLE FOR ANY CONSEQUENTIAL, SPECIAL, INDIRECT,
INCIDENTAL, OR PUNITIVE DAMAGES, HOWEVER CAUSED, ARISING IN ANY WAY
OUT OF YOUR USE OF THE CSM OR THIS DEVICE, WHETHER OR NOT TI HAS BEEN
ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. EXCLUDED DAMAGES INCLUDE,
BUT ARE NOT LIMITED TO LOSS OF DATA, LOSS OF GOODWILL, LOSS OF USE OR
INTERRUPTION OF BUSINESS OR OTHER ECONOMIC LOSS.
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2.2
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CSM Impact on Other On-Chip Resources
The CSM affects access to the on-chip resources listed in Table 10:
Table 10. Resources Affected by the CSM
Address
Block
0x00 0A80 - 0x00 0A87
Flash Configuration Registers
0x00 8000 - 0x00 83FF or
0x00 8000 - 0x00 8BFF or
0x00 8000 - 0x00 8FFF
L0 SARAM (1K X 16)
L0 SARAM (3K X 16)
L0 SARAM (4K X 16)
0x3F 4000 - 0x3F 7FFF or
0x3F 0000 - 0x3F 7FFF
Flash (16K X 16)
Flash (32K X 16)
0x3D 7800 - 0x3D 7BFF
User One-Time Programmable (OTP) (1K X 16)
0x3D 7C00 - 0x3D 7FFF
TI One-Time Programmable (OTP) (1) (1K X 16)
0x3F 8000 - 0x3F 83FF or
0x3F 8000 - 0x3F 8BFF or
0x3F 8000 - 0x3F 8FFF
L0 SARAM (1K X 16)
L0 SARAM (3K X 16)
L0 SARAM (4K X 16)
(1)
Not affected by ECSL
The Code Security Module has no impact whatsoever on the following on-chip resources:
• Single-access RAM (SARAM) blocks not designated as secure - These memory blocks can be freely
accessed and code run from them, whether the device is in secure or unsecure mode.
• Boot ROM contents - Visibility to the boot ROM contents is not impacted by the CSM.
• On-chip peripheral registers - The peripheral registers can be initialized by code running from on-chip
or off-chip memory, whether the device is in secure or unsecure mode.
• PIE Vector Table - Vector tables can be read and written regardless of whether the device is in secure
or unsecure mode. Table 10 and Table 11 show which on-chip resources are affected (or are not
affected) by the CSM.
Table 11. Resources Not Affected by the CSM
Address
Block
0x00 0000 - 0x00 03FF
M0 SARAM (1K X 16)
0x00 0400 - 0x00 07FF
M1 SARAM (1K X16)
0x00 0800 - 0x00 0CFF
Peripheral Frame 0 (2K X 16)
0x00 0D00 - 0x00 0FFF
PIE Vector RAM (256 X 16)
0x00 6000 - 0x00 6FFF
Peripheral Frame 1 (4K X 16)
0x00 7000 - 0x00 7FFF
Peripheral Frame 2 (4K X 16)
0x3F E000 - 0x3F FFFF
Boot ROM (4K X 16)
To summarize, it is possible to load code onto the unprotected on-chip program SARAM via the JTAG
connector without any impact from the Code Security Module. The code can be debugged and the
peripheral registers initialized, independent of whether the device is in secure or unsecure mode.
2.3
Incorporating Code Security in User Applications
Code security is typically not required in the development phase of a project; however, security is needed
once a robust code is developed. Before such a code is programmed in the flash memory, a password
should be chosen to secure the device. Once a password is in place, the device is secured (that is,
programming a password at the appropriate locations and either performing a device reset or setting the
FORCESEC bit (CSMSCR.15) is the action that secures the device). From that time on, access to debug
the contents of secure memory by any means (via JTAG, code running off external/on-chip memory, and
so on) requires the supply of a valid password. A password is not needed to run the code out of secure
memory (such as in a typical end-customer usage); however, access to secure memory contents for
debug purpose requires a password.
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Table 12. Code Security Module (CSM) Registers
Memory
Address
Register Name
Reset Values
Register Description
KEY Registers
0x00 - 0AE0
KEY0 (1)
0xFFFF
Low word of the 128-bit KEY register
0x00 - 0AE1
KEY1
(1)
0xFFFF
Second word of the 128-bit KEY register
0x00 - 0AE2
KEY2 (1)
0xFFFF
Third word of the 128-bit KEY register
0x00 - 0AE3
KEY3 (1)
0xFFFF
Fourth word of the 128-bit key
0x00 - 0AE4
KEY4 (1)
0xFFFF
Fifth word of the 128-bit key
0x00 - 0AE5
KEY5
(1)
0xFFFF
Sixth word of the 128-bit key
0x00 - 0AE6
KEY6 (1)
0xFFFF
Seventh word of the 128-bit key
0x00 - 0AE7
KEY7 (1)
0xFFFF
High word of the 128-bit KEY register
0x002F
CSM status and control register
0x00 - 0AEF
CSMSCR
(1)
Password Locations (PWL) in Flash Memory - Reserved for the CSM password only
0x3F - 7FF8
PWL0
User defined
Low word of the 128-bit password
0x3F - 7FF9
PWL1
User defined
Second word of the 128-bit password
0x3F - 7FFA
PWL2
User defined
Third word of the 128-bit password
0x3F - 7FFB
PWL3
User defined
Fourth word of the 128-bit password
0x3F - 7FFC
PWL4
User defined
Fifth word of the 128-bit password
0x3F - 7FFD
PWL5
User defined
Sixth word of the 128-bit password
0x3F - 7FFE
PWL6
User defined
Seventh word of the 128-bit password
0x3F - 7FFF
PWL7
User defined
High word of the 128-bit password
(1)
These registers are EALLOW protected. Refer to Section 5.2 for more information.
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Figure 11. CSM Status and Control Register (CSMSCR)
15
14
1
0
FORCESEC
Reserved
SECURE
W-0
R-0x002E
R-1
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 13. CSM Status and Control Register (CSMSCR) Field Descriptions
Bits
15
(1)
Field
Value
FORCESEC
14-1
Reserved
0
SECURE
Description
(1)
Writing a 1 clears the KEY registers and secures the device.
0
A read always returns a zero.
1
Clears the KEY registers and secures the device. The password match flow described in
Section 2.3.2 must be followed to unsecure the device again.
Reserved
Read-only bit that reflects the security state of the device.
0
Device is unsecure (CSM unlocked).
1
Device is secure (CSM locked).
This register is EALLOW protected. Refer to Section 5.2 for more information.
2.3.1
Environments That Require Security Unlocking
Following are the typical situations under which unsecuring can be required:
• Code development using debuggers (such as Code Composer Studio ).
This is the most common environment during the design phase of a product.
• Flash programming using TI's flash utilities such as Code Composer Studio F28xx On-Chip Flash
Programmer plug-in.
Flash programming is common during code development and testing. Once the user supplies the
necessary password, the flash utilities disable the security logic before attempting to program the flash.
The flash utilities can disable the code security logic in new devices without any authorization, since
new devices come with an erased flash. However, reprogramming devices (that already contain a
custom password) require the password to be supplied to the flash utilities in order to unlock the device
to enable programming. In custom programming solutions that use the flash API supplied by TI
unlocking the CSM can be avoided by executing the flash programming algorithms from secure
memory.
• Custom environment defined by the application
In addition to the above, access to secure memory contents can be required in situations such as:
• Using the on-chip bootloader to load code or data into secure SARAM or to erase/program the flash.
• Executing code from on-chip unsecure memory and requiring access to secure memory for lookup
table. This is not a suggested operating condition as supplying the password from external code could
compromise code security.
The unsecuring sequence is identical in all the above situations. This sequence is referred to as the
password match flow (PMF) for simplicity. Figure 12 explains the sequence of operation that is required
every time the user attempts to unsecure a device. A code example is listed for clarity.
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2.3.2
Password Match Flow
Password match flow (PMF) is essentially a sequence of eight dummy reads from password locations
(PWL) followed by eight writes to KEY registers.
Figure 12 shows how the PMF helps to initialize the security logic registers and disable security logic.
Figure 12. Password Match Flow (PMF)
Start
Device secure after
reset or runtime
KEY registers = all ones
Do dummy read of PWL
0x3F 7FF8 − 0x3F 7FFF
Device permanently secured
Are PWL =
all zeros?
Yes
CPU access is limited.
Device cannot be debugged
or reprogrammed.
No
Yes
Are PWL =
all Fs?
No
Write the password to
KEY registers
0x00 0AE0 − 0x00 0AE7
(A)
Device unsecure
Correct
password?
Yes
User can access
on-chip secure
memory
No
A
The KEY registers are EALLOW protected.
NOTE: Any read of the CSM password would yield 0x0000 until the device is unlocked. These reads are
labeled "dummy read" or a "fake read". The application reads the password locations, but will always get
0's no matter what the actual value is. What is important is the actual value of the password. If the actual
value is all 0xFFFF, then doing this "dummy read" will unlock the device. If the actual value is all 0x0000,
then no matter what the application code does, one will never be able to unlock the device. If the actual
value is something other than all 0xFFFF or 0x0000, then when the dummy read is performed, the actual
value must match the password the user provided.
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2.3.3
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Unsecuring Considerations for Devices With/Without Code Security
Case 1 and Case 2 provide unsecuring considerations for devices with and without code security.
Case 1: Device With Code
Security
A device with code security should have a predetermined password stored in the password locations
(0x3F 7FF8 - 0x3F 7FFF in memory). In addition, locations 0x3F 7F80 - 0x3F 7FF5 should be
programmed with all 0x0000 and not used for program and/or data storage. The following are steps to
unsecure this device:
1. Perform a dummy read of the password locations.
2. Write the password into the KEY registers (locations 0x00 0AE0 - 0x00 0AE7 in memory).
3. If the password is correct, the device becomes unsecure; otherwise, it stays secure.
Case 2: Device Without Code Security
A device without code security should have 0x FFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFF (128 bits
of all ones) stored in the password locations. The following are steps to use this device:
1. At reset, the CSM will lock memory regions protected by the CSM.
2. Perform a dummy read of the password locations.
3. Since the password is all ones, this alone will unlock all memory regions. Secure memory is fully
accessible immediately after this operation is completed.
NOTE: Even if a device is not protected with a password (all password locations all ones), the CSM
will lock at reset. Thus, a dummy read operation must still be performed on these devices
prior to reading, writing, or programming secure memory if the code performing the access is
executing from outside of the CSM protected memory region. The Boot ROM code does this
dummy read for convenience.
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2.3.3.1
C Code Example to Unsecure
volatile int *CSM = (volatile int *)0x000AE0; //CSM register file
volatile int *PWL = (volatile int *)0x003F7FF8; //Password location
volatile int tmp;
int I;
// Read the 128-bits of the password locations (PWL)
// in flash at address 0x3F 7FF8 - 0x3F 7FFF
// If the device is secure, then the values read will
// not actually be loaded into the temp variable, so
// this is called a dummy read.
for (I=0; i<8; I++) tmp = *PWL++;
// If the password locations (PWL) are all = ones (0xFFFF),
// then the device will now be unsecure. If the password
// is not all ones (0xFFFF), then the code below is required
// to unsecure the CSM.
// Write the 128-bit password to the KEY registers
// If this password matches that stored in the
// PWL then the CSM will become unsecure. If it does not
// match, then the device will remain secure.
// An example password of:
// 0x11112222333344445555666677778888 is used.
asm(" EALLOW"); // Key registers are EALLOW protected
*CSM++ = 0x1111; // Register KEY0 at 0xAE0
*CSM++ = 0x2222; // Register KEY1 at 0xAE1
*CSM++ = 0x3333; // Register KEY2 at 0xAE2
*CSM++ = 0x4444; // Register KEY3 at 0xAE3
*CSM++ = 0x5555; // Register KEY4 at 0xAE4
*CSM++ = 0x6666; // Register KEY5 at 0xAE5
*CSM++ = 0x7777; // Register KEY6 at 0xAE6
*CSM++ = 0x8888; // Register KEY7 at 0xAE7
asm(" EDIS");
2.3.3.2
C Code Example to Resecure
volatile int *CSMSCR = 0x00AEF;
asm(" EALLOW");
//CSMSCR register
//Set FORCESEC bit
//CSMSCR register is EALLOW protected.
*CSMSCR = 0x8000;
asm("EDIS");
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Code Security Module (CSM)
2.4
Do's and Don'ts to Protect Security Logic
2.4.1
•
•
•
•
2.4.2
•
•
•
•
2.5
www.ti.com
Do's
To keep the debug and code development phase simple, use the device in the unsecure mode; that is,
use all 128 bits as ones in the password locations (or use a password that is easy to remember). Use
a password after the development phase when the code is frozen.
Recheck the password stored in the password locations before programming the COFF file using flash
utilities.
The flow of code execution can freely toggle back and forth between secure memory and unsecure
memory without compromising security. To access data variables located in secure memory when the
device is secured, code execution must currently be running from secure memory.
Program locations 0x3F 7F80 - 0x3F 7FF5 with 0x0000 when using the CSM.
Don'ts
If code security is desired, do not embed the password in your application anywhere other than in the
password locations or security can be compromised.
Do not use 128 bits of all zeros as the password. This automatically secures the device, regardless of
the contents of the KEY register. The device is not debuggable nor reprogrammable.
Do not pull a reset during an erase operation on the flash array. This can leave either zeros or an
unknown value in the password locations. If the password locations are all zero during a reset, the
device will always be secure, regardless of the contents of the KEY register.
Do not use locations 0x3F 7F80 - 0x3F 7FF5 to store program and/or data. These locations should be
programmed to 0x0000 when using the CSM.
CSM Features - Summary
1. The flash is secured after a reset until the password match flow described in Section 2.3.2 is executed.
2. The standard way of running code out of the flash is to program the flash with the code and power up
the device. Since instruction fetches are always allowed from secure memory, regardless of the state
of the CSM, the code functions correctly even without executing the password match flow.
3. Secure memory cannot be modified by code executing from unsecure memory while the device is
secured.
4. Secure memory cannot be read from any code running from unsecure memory while the device is
secured.
5. Secure memory cannot be read or written to by the debugger (Code Composer Studio) at any time that
the device is secured.
6. Complete access to secure memory from both the CPU code and the debugger is granted while the
device is unsecured.
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Clocking
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3
Clocking
This section describes the oscillator, PLL and clocking mechanisms, the watchdog function, and the lowpower modes.
3.1
Clocking and System Control
Figure 13 shows the various clock and reset domains.
Figure 13. Clock and Reset Domains
PCLKCR0/1/3
(System Control Regs)
LSPCLK
Clock Enables
LOSPCP
(System Control Regs)
C28x Core
Peripheral
Registers
SPI-A, SCI-A
I/ O
SYSCLKOUT
Clock Enables
GPIO
Mux
I/ O
ECAP1
Peripheral
Registers
EPWM1/.../5
Peripheral
Registers
Clock Enables
I/ O
I2C-A
Peripheral
Registers
12-Bit ADC
ADC
Registers
COMP1/2
Comparator
Registers
Bridge
Memory Bus
I/ O
Peripheral Bus
Clock Enables
Clock Enables
16 Ch
Analog
GPIO
Mux
Clock Enables
6
The PLL, clocking, watchdog and low-power modes, are controlled by the registers listed in Table 14.
Table 14. PLL, Clocking, Watchdog, and Low-Power Mode Registers
Name
Address
Size
(x16)
Description
XCLK
0x0000-7010
1
XCLKOUT/XCLKIN Control
PLLSTS
0x0000-7011
1
PLL Status Register
CLKCTL
0x0000-7012
1
Clock Control Register
PLLLOCKPRD
0x0000-7013
1
PLL Lock Period Register
INTOSC1TRIM
0x0000-7014
1
Internal Oscillator 1 Trim Register
INTOSC2TRIM
0x0000-7016
1
Internal Oscillator 2 Trim Register
LOSPCP
0x0000-701B
1
Low-Speed Peripheral Clock Pre-Scaler Register
PCLKCR0
0x0000-701C
1
Peripheral Clock Control Register 0
PCLKCR1
0x0000-701D
1
Peripheral Clock Control Register 1
LPMCR0
0x0000-701E
1
Low Power Mode Control Register 0
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Table 14. PLL, Clocking, Watchdog, and Low-Power Mode Registers (continued)
Name
Address
Size
(x16)
PCLKCR3
0x0000-7020
1
Peripheral Clock Control Register 3
PLLCR
0x0000-7021
1
PLL Control Register
SCSR
0x0000-7022
1
System Control and Status Register
WDCNTR
0x0000-7023
1
Watchdog Counter Register
WDKEY
0x0000-7025
1
Watchdog Reset Key Register
WDCR
0x0000-7029
1
Watchdog Control Register
0x000985
1
BOR Configuration Register
BORCFG
3.1.1
Description
Enabling/Disabling Clocks to the Peripheral Modules
The PCLKCR0/1/3 registers enable/disable clocks to the various peripheral modules. There is a 2SYSCLKOUT cycle delay from when a write to the PCLKCR0/1/3 registers occurs to when the action is
valid. This delay must be taken into account before attempting to access the peripheral configuration
registers. Due to the peripheral-GPIO multiplexing at the pin level, all peripherals cannot be used at the
same time. While it is possible to turn on the clocks to all the peripherals at the same time, such a
configuration may not be useful. If this is done, the current drawn will be more than required. To avoid this,
only enable the clocks required by the application.
Figure 14. Peripheral Clock Control 0 Register (PCLKCR0)
15
11
7
10
9
8
Reserved
SCIAENCLK
Reserved
SPIAENCLK
R-0
R/W-0
R-0
R/W-0
4
3
2
1
0
Reserved
5
I2CAENCLK
ADCENCLK
TBCLKSYNC
Reserved
HRPWMENCLK
R-0
R/W-0
R/W-0
R/W-0
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 15. Peripheral Clock Control 0 Register (PCLKCR0) Field Descriptions
Bit
15-11
10
Description
Any writes to these bit(s) must always have a value of 0.
SCIAENCLK
SCI-A clock enable
(1)
0
The SCI-A module is not clocked. (default)
1
The SCI-A module is clocked by the low-speed clock (LSPCLK).
Reserved
Any writes to these bit(s) must always have a value of 0.
8
SPIAENCLK
SPI-A clock enable
4
3
32
Value
Reserved
9
7-5
(1)
Field
(1)
0
The SPI-A module is not clocked. (default)
1
The SPI-A module is clocked by the low-speed clock (LSPCLK).
Reserved
Any writes to these bit(s) must always have a value of 0.
I2CAENCLK
I2C clock enable
0
The I2C module is not clocked. (default) (1)
1
The I2C module is clocked.
ADCENCLK
ADC clock enable
0
The ADC is not clocked. (default)
1
The ADC module is clocked
(1)
If a peripheral block is not used, the clock to that peripheral can be turned off to minimize power consumption.
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Table 15. Peripheral Clock Control 0 Register (PCLKCR0) Field Descriptions (continued)
Bit
Field
2
Value
TBCLKSYNC
Description
ePWM Module Time Base Clock (TBCLK) Sync: Allows the user to globally synchronize all enabled
ePWM modules to the time base clock (TBCLK):
0
The TBCLK (Time Base Clock) within each enabled ePWM module is stopped. (default). If,
however, the ePWM clock enable bit is set in the PCLKCR1 register, then the ePWM module will
still be clocked by SYSCLKOUT even if TBCLKSYNC is 0.
1
All enabled ePWM module clocks are started with the first rising edge of TBCLK aligned. For
perfectly synchronized TBCLKs, the prescaler bits in the TBCTL register of each ePWM module
must be set identically. The proper procedure for enabling ePWM clocks is as follows:
•
•
•
•
Enable ePWM module clocks in the PCLKCR1 register.
Set TBCLKSYNC to 0.
Configure prescaler values and ePWM modes.
Set TBCLKSYNC to 1.
1
Reserved
Any writes to these bit(s) must always have a value of 0.
0
HRPWMENCLK
HRPWM clock enable
0
HRPWM is not enabled.
1
HRPWM is enabled.
Figure 15. Peripheral Clock Control 1 Register (PCLKCR1)
15
9
7
8
Reserved
ECAP1ENCLK
R-0
R/W-0
4
Reserved
3
2
1
0
EPWM4ENCLK EPWM3ENCLK EPWM2ENCLK EPWM1ENCLK
R-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 16. Peripheral Clock Control 1 Register (PCLKCR1) Field Descriptions
Bits
15-9
8
7-4
3
2
1
0
(1)
(2)
(3)
Field
Value
Description
(1)
Reserved
Any writes to these bit(s) must always have a value of 0.
ECAP1ENCLK
eCAP1 clock enable
(2)
0
The eCAP1 module is not clocked. (default)
1
The eCAP1 module is clocked by the system clock (SYSCLKOUT).
Reserved
Any writes to these bit(s) must always have a value of 0.
EPWM4ENCLK
ePWM4 clock enable.
(3)
(2)
0
The ePWM4 module is not clocked. (default)
1
The ePWM4 module is clocked by the system clock (SYSCLKOUT).
EPWM3ENCLK
ePWM3 clock enable.
(3)
(2)
0
The ePWM3 module is not clocked. (default)
1
The ePWM3 module is clocked by the system clock (SYSCLKOUT).
EPWM2ENCLK
ePWM2 clock enable.
(3)
(2)
0
The ePWM2 module is not clocked. (default)
1
The ePWM2 module is clocked by the system clock (SYSCLKOUT).
EPWM1ENCLK
ePWM1 clock enable.
(3)
(2)
0
The ePWM1 module is not clocked. (default)
1
The ePWM1 module is clocked by the system clock (SYSCLKOUT).
This register is EALLOW protected. See Section 5.2 for more information.
If a peripheral block is not used, the clock to that peripheral can be turned off to minimize power consumption.
To start the ePWM Time-base clock (TBCLK) within the ePWM modules, the TBCLKSYNC bit in PCLKCR0 must also be set.
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Figure 16. Peripheral Clock Control 3 Register (PCLKCR3)
15
14
10
9
8
Reserved
GPIOINENCLK
13
12
Reserved
11
CPUTIMER2ENCLK
CPUTIMER1ENCLK
CPUTIMER0ENCLK
R-0
R/W-1
R-0
R/W-1
R/W-1
R/W-1
7
2
Reserved
1
0
COMP2ENCLK
COMP1ENCLK
R-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 17. Peripheral Clock Control 3 Register (PCLKCR3) Field Descriptions
Bit
15-14
13
12-11
10
9
8
7:2
1
0
34
Field
Value
Reserved
Any writes to these bit(s) must always have a value of 0.
GPIOINENCLK
GPIO Input Clock Enable
0
The GPIO module is not clocked.
1
The GPIO module is clocked.
Reserved
Any writes to these bit(s) must always have a value of 0.
CPUTIMER2ENCLK
CPU Timer 2 Clock Enable
0
The CPU Timer 2 is not clocked.
1
The CPU Timer 2 is clocked.
CPUTIMER1ENCLK
CPU Timer 1 Clock Enable
0
The CPU Timer 1 is not clocked.
1
The CPU Timer 1 is clocked.
CPUTIMER0ENCLK
CPU Timer 0 Clock Enable
0
The CPU Timer 0 is not clocked.
1
The CPU Timer 0 is clocked.
Reserved
Any writes to these bit(s) must always have a value of 0.
COMP2ENCLK
Comparator2 clock enable
0
Comparator2 is not clocked
1
Comparator2 is clocked
COMP1ENCLK
System Control
Description
Comparator1 clock enable
0
Comparator1 is not clocked
1
Comparator1 is clocked
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3.1.2
Configuring the Low-Speed Peripheral Clock Prescaler
The low-speed peripheral clock prescale (LOSPCP) registers are used to configure the low-speed
peripheral clocks. See Figure 17 for the LOSPCP layout.
Figure 17. Low-Speed Peripheral Clock Prescaler Register (LOSPCP)
15
3
2
0
Reserved
LSPCLK
R-0
R/W-010
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 18. Low-Speed Peripheral Clock Prescaler Register (LOSPCP) Field Descriptions
Bits
Field
Value
Description
(1)
15-3
Reserved
Any writes to these bit(s) must always have a value of 0.
2-0
LSPCLK
These bits configure the low-speed peripheral clock (LSPCLK) rate relative to SYSCLKOUT:
If LOSPCP (2) ≠ 0, then LSPCLK = SYSCLKOUT/(LOSPCP X 2)
If LOSPCP = 0, then LSPCLK = SYSCLKOUT
(1)
(2)
000
Low speed clock = SYSCLKOUT/1
001
Low speed clock= SYSCLKOUT/2
010
Low speed clock= SYSCLKOUT/4 (reset default)
011
Low speed clock= SYSCLKOUT/6
100
Low speed clock= SYSCLKOUT/8
101
Low speed clock= SYSCLKOUT/10
110
Low speed clock= SYSCLKOUT/12
111
Low speed clock= SYSCLKOUT/14
This register is EALLOW protected. See Section 5.2 for more information.
LOSPCP in this equation denotes the value of bits 2:0 in the LOSPCP register.
3.2
OSC and PLL Block
The on-chip oscillator and phase-locked loop (PLL) block provide the clocking signals for the device, as
well as control for low-power mode (LPM) entry/exit.
3.2.1
Input Clock Options
These devices have two internal oscillators (INTOSC1 and INTOSC2) that need no external components.
They also have an on-chip, PLL-based clock module. Figure 18 shows the different options that are
available to clock the device. Following are the input clock options available:
• INTOSC1 (Internal zero-pin Oscillator 1): This is the on-chip internal oscillator 1. This can provide
the clock for the Watchdog block, core and CPU-Timer 2. This is the default clock source upon reset.
• INTOSC2 (Internal zero-pin Oscillator 2): This is the on-chip internal oscillator 2. This can provide
the clock for the Watchdog block, core and CPU-Timer 2. Both INTOSC1 and INTOSC2 can be
independently chosen for the Watchdog block, core and CPU-Timer 2.
• Crystal/Resonator Operation: The on-chip crystal oscillator enables the use of an external
crystal/resonator attached to the device to provide the time base. The crystal/resonator is connected to
the X1/X2 pins.
• External clock source operation: If the on-chip crystal oscillator is not used, this mode allows it to be
bypassed. The device clock is generated from an external clock source input on the XCLKIN pin. Note
that the XCLKIN is multiplexed with a GPIO19 or GPIO38 pin. The XCLKIN input can be selected as
GPIO19 or GPIO38 via the XCLKINSEL bit in the XCLK register. The CLKCTL[XCLKINOFF] bit
disables this clock input (forced low). If the clock source is not used or the respective pins are used as
GPIOs, the user should disable it at boot time.
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Figure 18. Clocking Options
CLKCTL[WDCLKSRCSEL]
INTOSC1TRIM Reg
Internal
OSC 1
(10 MHz)
(A)
0
OSC1CLK
OSCCLKSRC1
WDCLK
CPU-watchdog
(OSC1CLK on XRS reset)
OSCE
1
CLKCTL[INTOSC1OFF]
1 = Turn OSC Off
CLKCTL[INTOSC1HALT]
CLKCTL[OSCCLKSRCSEL]
WAKEOSC
1 = Ignore HALT
INTOSC2TRIM Reg
0
Internal OSC2CLK
OSC 2
(10 MHz)
(A)
OSCCLK
PLL /
Missing-clock-detect circuit
(OSC1CLK on XRS reset)
(B)
1
OSCE
CLKCTL[TMR2CLKPRESCALE]
CLKCTL[TMR2CLKSRCSEL]
1 = Turn OSC Off
10
CLKCTL[INTOSC2OFF]
11
1 = Ignore HALT
1
Prescale
/1, /2, /4,
/8, /16
01, 10, 11
CPUTMR2CLK
01
00
CLKCTL[INTOSC2HALT]
SYSCLKOUT
OSCCLKSRC2
0
0 = GPIO38
1 = GPIO19
XCLK[XCLKINSEL]
SYNC
Edge
Detect
CLKCTL[OSCCLKSRC2SEL]
CLKCTL[XCLKINOFF]
0
GPIO19
or
GPIO38
(from
external oscillator)
XCLKIN
1
0
XCLKIN
X1
(Crystal)
OSC
XTAL
EXTCLK
WAKEOSC
(Oscillators enabled when this signal is high)
X2
CLKCTL[XTALOSCOFF]
36
0 = OSC on (default on reset)
1 = Turn OSC off
A
Register loaded from TI OTP-based calibration function.
B
See the device-specific datasheet for details on missing clock detection.
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3.2.1.1
Trimming INTOSCn
The nominal frequency of both INTOSC1 and INTOSC2 is 10 MHz. Two 16-bit registers are provided for
trimming each oscillator at manufacturing time (called coarse trim) and also provide you with a way to trim
the oscillator using software (called fine trim). Both registers are the same so only one is shown with "n" in
place of the numbers 1 or 2.
Figure 19. Internal Oscillator n Trim (INTOSCnTRIM) Register
15
14
9
8
Reserved
FINETRIM
Reserved
R-0
R/W-0
R-0
7
0
COARSETRIM
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 19. Internal Oscillator n Trim (INTOSCnTRIM) Register Field Descriptions
Bit
Field
Description
(1)
15
Reserved
Any writes to these bit(s) must always have a value of 0.
14-9
FINETRIM
6-bit Fine Trim Value: Signed magnitude value (- 31 to + 31)
8
Reserved
Any writes to these bits must always have a value of 0.
COARSETRIM
8-bit Coarse Trim Value: Signed magnitude value (- 127 to + 127)
7-0
(1)
Value
The internal oscillators are software trimmed with parameters stored in OTP. During boot time, the boot-ROM copies this value to the
above registers.
3.2.1.2
Device_Cal
The Device_cal() routine is programmed into TI reserved memory by the factory. The boot ROM
automatically calls the Device_cal() routine to calibrate the internal oscillators and ADC with device
specific calibration data. During normal operation, this process occurs automatically and no action is
required by the user.
If the boot ROM is bypassed by Code Composer Studio during the development process, then the
calibration must be initialized by application. For working examples, see the system initialization in the
C2802x C/C++ Header Files and Peripheral Examples.
NOTE: Failure to initialize these registers will cause the oscillators and ADC to function out of
specification. The following three steps describe how to call the Device_cal routine from an
application.
Step 1: Create a pointer to the Device_cal function as shown in Example 1. This #define is included in the
Header Files and Peripheral Examples.
Step 2: Call the function pointed to by Device_cal() as shown in Example 1. The ADC clocks must be
enabled before making this call.
Example 1. Calling the Device_cal() function
//Device_cal is a pointer to a function
//that begins at the address shown
# define Device_cal (void(*)(void))0x3D7C80
... ...
EALLOW;
SysCtrlRegs.PCLKCR0.bit.ADCENCLK = 1;
(*Device_cal)();
SysCtrlRegs.PCLKCR0.bit.ADCENCLK = 0;
EDIS;
...
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Configuring Input Clock Source and XCLKOUT Options
The XCLK register is used to choose the GPIO pin for XCLKIN input and to configure the XCLKOUT pin
frequency.
Figure 20. Clocking (XCLK) Register
15
8
Reserved
R-0
7
6
Reserved
XCLKINSEL
5
Reserved
2
1
XCLKOUTDIV
0
R-0
R/W-0
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 20. Clocking (XCLK) Field Descriptions
Bit
Field
15-7
Reserved
6
(1)
Value
Description
(1)
Any writes to these bit(s) must always have a value of 0.
XCLKINSEL
XCLKIN Source Select Bit: This bit selects the source
0
GPIO38 is XCLKIN input source (this is also the JTAG port TCK source)
1
GPIO19 is XCLKIN input source
5-2
Reserved
Any writes to these bit(s) must always have a value of 0.
1-0
XCLKOUTDIV (2)
XCLKOUT Divide Ratio: These two bits select the XCLKOUT frequency ratio relative to
SYSCLKOUT. The ratios are:
00
XCLKOUT = SYSCLKOUT/4
01
XCLKOUT = SYSCLKOUT/2
10
XCLKOUT = SYSCLKOUT
11
XCLKOUT = Off
The XCLKINSEL bit in the XCLK register is reset by XRS input signal.
Refer to the device datasheet for the maximum permissible XCLKOUT frequency.
(2)
3.2.3
Configuring Device Clock Domains
The CLKCTL register is used to choose between the avaliable clock sources and also configure device
behavior during clock failure.
Figure 21. Clock Control (CLKCTL) Register
15
14
13
12
11
10
9
8
NMIRESETSEL
XTALOSCOFF
XCLKINOFF
WDHALTI
INTOSC2HALTI
INTOSC2OFF
INTOSC1HALTI
INTOSC1OFF
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
5
4
3
7
2
1
0
TMR2CLKPRESCALE
TMR2CLKSRCSEL
WDCLKSRCSEL
OSCCLKSRC2SEL
OSCCLKSRCSEL
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 21. Clock Control (CLKCTL) Register Field Descriptions
Bit
Field
15
NMIRESETSEL
Value
Description
NMI Reset Select Bit: This bit selects between generating the MCLKRS signal directly
when a missing clock condition is detected or the NMIRS reset is used:
0
MCLKRS is driven without any delay (default on reset)
1
NMI Watcdog Reset (NMIRS) initiates MCLKRS
Note: The CLOCKFAIL signal is generated regardless of this mode selection.
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Table 21. Clock Control (CLKCTL) Register Field Descriptions (continued)
Bit
Field
14
XTALOSCOFF
13
Value
Description
Crystal Oscillator Off Bit: This bit could be used to turn off the crystal oscillator if it is not
used.
0
Crystal oscillator on (default on reset)
1
Crystal oscillator off
XCLKINOFF
XCLKIN Off Bit: This bit turns external XCLKIN oscillator input off:
0
XCLKIN oscillator input on (default on reset)
1
XCLKIN oscillator input off
Note: You need to select XCLKIN GPIO pin source via the XCLKINSEL bit in the XCLK
register. See the XCLK register description for more details. XTALOSCOFF must be set to
1 if XCLKIN is used.
12
11
10
9
8
7-5
4-3
WDHALTI
Watchdog HALT Mode Ignore Bit: This bit selects if the watchdog is automatically turned
on/off by the HALT mode or not. This feature can be used to allow the selected WDCLK
source to continue clocking the watchdog when HALT mode is active. This would enable
the watchdog to periodically wake up the device.
0
Watchdog Automatically Turned On/Off By HALT (default on reset)
1
Watchdog Ignores HALT Mode
INTOSC2HALTI
Internal Oscillator 2 HALT Mode Ignore Bit: This bit selects if the internal oscillator 2 is
automatically turned on/off by the HALT mode or not. This feature can be used to allow the
internal oscillator to continue clocking when HALT mode is active. This would enable a
quicker wake-up from HALT.
0
Internal Oscillator 2 Automatically Turned On/Off By HALT (default on reset)
1
Internal Oscillator 2 Ignores HALT Mode
INTOSC2OFF
Internal Oscillator 2 Off Bit: This bit turns oscillator 2 off:
0
Internal Oscillator 2 On (default on reset)
1
Internal Oscillator 2 Off. This bit could be used by the user to turn off the internal oscillator
2 if it is not used. This selection is not affected by the missing clock detect circuit.
INTOSC1HALTI
Internal Oscillator 1 HALT Mode Ignore Bit: This bit selects if the internal oscillator 1 is
automatically turned on/off by the HALT mode or not:
0
Internal Oscillator 1 Automatically Turned On/Off By HALT (default on reset)
1
Internal Oscillator 1 Ignores HALT Mode. This feature can be used to allow the internal
oscillator to continue clocking when HALT mode is active. This would enable a quicker
wake-up from HALT.
INTOSC1OFF
Internal Oscillator 1 Off Bit: This bit turns oscillator 1 off:
0
Internal Oscillator 1 On (default on reset)
1
Internal Oscillator 1 Off. This bit could be used by the user to turn off the internal oscillator
1 if it is not used. This selection is not affected by the missing clock detect circuit.
TMR2CLKPRESCALE
CPU Timer 2 Clock Pre-Scale Value: These bits select the pre-scale value for the selected
clock source for CPU Timer 2. This selection is not affected by the missing clock detect
circuit.
000
/1 (default on reset)
001
/2
010
/4
011
/8
100
/16
101
Reserved
110
Reserved
111
Reserved
TMR2CLKSRCSEL
CPU Timer 2 Clock Source Select Bit: This bit selects the source for CPU Timer 2:
00
SYSCLKOUT Selected (default on reset, pre-scaler is bypassed)
01
External Oscillator Selected (at XOR output)
10
Internal Oscillator 1 Selected
11
Internal Oscillator 2 Selected. This selection is not affected by the missing clock detect
circuit.
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Table 21. Clock Control (CLKCTL) Register Field Descriptions (continued)
Bit
Field
2
Value
WDCLKSRCSEL
1
Watchdog Clock Source Select Bit: This bit selects the source for WDCLK. On XRS low
and after XRS goes high, internal oscillator 1 is selected by default. User would need to
select external oscillator or Internal Oscillator 2 during their initialization process. If missing
clock detect circuit detects a missing clock, then this bit is forced to 0 and internal oscillator
1 is selected. The user changing this bit does not affect the PLLCR value.
0
Internal Oscillator 1 Selected (default on reset)
1
External Oscillator or Internal Oscillator 2 Selected
OSCCLKSRC2SEL
0
Oscillator 2 Clock Source Select Bit: This bit selects between internal oscillator 2 or
external oscillator. This selection is not affected by the missing clock detect circuit.
0
External Oscillator Selected (default on reset)
1
Internal Oscillator 2 Selected
OSCCLKSRCSEL
3.2.3.1
Description
Oscillator Clock Source Select Bit. This bit selects the source for OSCCLK. On XRS low
and after XRS goes high, internal oscillator 1 is selected by default. User would need to
select external oscillator or Internal Oscillator 2 during their initialization process. Whenever
the user changes the clock source, using these bits, the PLLCR register will be
automatically forced to zero. This prevents potential PLL overshoot. The user will then have
to write to the PLLCR register to configure the appropriate divisor ratio. The user can also
configure the PLL lock period using the PLLLOCKPRD register to reduce the lock time if
necessary. If missing clock detect circuit detects a missing clock, then this bit is
automatically forced to 0 and internal oscillator 1 is selected. The PLLCR register will also
be automatically forced to zero to prevent any potential overshoot.
0
Internal Oscillator 1 Selected (default on reset)
1
External Oscillator or Internal Oscillator 2 Selected Note: If users wish to use Oscillator 2 or
External Oscillator to clock the CPU, they should configure the OSCCLKSRC2SEL bit first,
and then write to the OSCCLKSRCSEL bit next.
Switching the Input Clock Source
The following procedure may be used to switch clock sources:
1. Use CPU Timer 2 to detect if clock sources are functional.
2. If any of the clock sources is not functional, turn off the respective clock source (using the respective
CLKCTL bit).
3. Switch over to a new clock source.
4. If clock source switching occurred while in Limp Mode, then write a 1 to MCLKCLR to exit Limp Mode.
If External Oscillator or XCLKIN or Internal Oscillator 2 (OSCCLKSRC2) is selected and a missing clock is
detected, the missing clock detect circuit will automatically switch to Internal Oscillator 1 (OSCCLKSRC1)
and generate a CLOCKFAIL signal. In addition, the PLLCR register is forced to zero (PLL is bypassed) to
prevent any potential overshoot. The user can then write to the PLLCR register to re-lock the PLL. Under
this situation, the missing clock detect circuit will be automatically re-enabled (PLLSTS[MCLKSTS] bit will
be automatically cleared). If Internal Oscillator 1 (OSCCLKSRC1) should also fail, then under this
situation, the missing clock detect circuit will remain in limp mode. The user will have to re-enable the logic
via the PLLSTS[MCLKCLR] bit.
3.2.3.2
Switching to INTOSC2 in the Absence of External Clocks
For the device to work properly upon a switch from INTOSC1 to INTOSC2 in the absence of any external
clock, the application code needs to write a 1 to the CLKCTL.XTALOSCOFF and CLKCTL.XCLKINOFF
bits first. This is to indicate to the clock switching circuitry that external clocks are not present. Only after
this should the OSCCLKSRCSEL and OSCCLKSRC2SEL bits be written to. Note that this sequence
should be separated into two writes as follows:
First write → CLKCTL.XTALOSCOFF=1 and CLKCTL.XCLKINOFF=1
Second write → CLKCTL.OSCCLKLSRCSEL=1 and CLKCTL.OSCCLKSRC2SEL=1
The second write should not alter the values of XTALOSCOFF and XCLKINOFF bits. If the DSP28 header
files (SPRC823) supplied by Texas Intruments are used, clock switching can be achieved with the
following code snip:
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SysCtrlRegs.CLKCTL.all = 0x6000; // Set XTALOSCOFF=1 & XCLKINOFF=1
SysCtrlRegs.CLKCTL.all = 0x6003; // Set OSCCLKLSRCSEL=1 & OSCCLKSRC2SEL=1
The system initialization file (DSP2802x_SysCtrl.c ) provided as part of the header files also contain
functions to switch to different clock sources. If an attempt is made to switch from INTOSC1 to INTOSC2
without the write to the XTALOSCOFF and XCLKINOFF bits, a missing clock will be detected due to the
absence of external clock source (even after the proper source selection). The PLLCR will be zeroed out
and the device will automatically clear the MCLKSTS bit and switch back INTOSC1.
3.2.4
PLL-based Clock Module
The figure below shows the OSC and PLL block diagram.
Figure 22. OSC and PLL Block
OSCCLK
OSCCLK
0
PLLSTS[OSCOFF]
PLL
OSCCLK or
VCOCLK
VCOCLK
n
/1
/2
CLKIN
To
CPU
/4
n≠ 0
PLLSTS[PLLOFF]
PLLSTS[DIVSEL]
4-bit Multiplier PLLCR[DIV]
The following is applicable for devices that have X1 and X2 pins:
When using XCLKIN as the external clock source, you must tie X1 low and leave X2 disconnected.
Table 22. Possible PLL Configuration Modes
PLL Mode
Remarks
PLLSTS[DIVSEL]
(1)
CLKIN and
SYSCLKOUT
(2)
PLL Off
Invoked by the user setting the PLLOFF bit in the PLLSTS register. The
PLL block is disabled in this mode. The CPU clock (CLKIN) can then be
derived directly from any one of the following sources: INTOSC1,
INTOSC2, XCLKIN pin, X1 pin or X1/X2 pins.This can be useful to
reduce system noise and for low power operation. The PLLCR register
must first be set to 0x0000 (PLL Bypass) before entering this mode. The
CPU clock (CLKIN) is derived directly from the input clock on either
X1/X2, X1 or XCLKIN.
0, 1
2
3
OSCCLK/4
OSCCLK/2
OSCCLK/1
PLL Bypass
PLL Bypass is the default PLL configuration upon power-up or after an
external reset (XRS). This mode is selected when the PLLCR register is
set to 0x0000 or while the PLL locks to a new frequency after the
PLLCR register has been modified. In this mode, the PLL itself is
bypassed but the PLL is not turned off.
0, 1
2
3
OSCCLK/4
OSCCLK/2
OSCCLK/1
0, 1
2
3
OSCCLK*n/4
OSCCLK*n/2
OSCCLK*n/1
PLL Enabled Achieved by writing a non-zero value n into the PLLCR register. Upon
writing to the PLLCR, the device will switch to PLL Bypass mode until
the PLL locks.
(1)
(2)
PLLSTS[DIVSEL] must be 0 before writing to the PLLCR and should be changed only after PLLSTS[PLLLOCKS] = 1. See
Figure 26.
The input clock and PLLCR[DIV] bits should be chosen in such a way that the output frequency of the PLL (VCOCLK) is a
minimum of 50 MHz.
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Input Clock Fail Detection
It is possible for the clock source of the device to fail. When the PLL is not disabled, the main oscillator fail
logic allows the device to detect this condition and default to a known state as described in this section.
Two counters are used to monitor the presence of the OSCCLK signal as shown in Figure 23. The first
counter is incremented by the OSCCLK signal itself. When the PLL is not turned off, the second counter is
incremented by the VCOCLK coming out of the PLL block. These counters are configured such that when
the 7-bit OSCCLK counter overflows, it clears the 13-bit VCOCLK counter. In normal operating mode, as
long as OSCCLK is present, the VCOCLK counter will never overflow.
Figure 23. Oscillator Logic Diagram
WDINT
WD
Block
WAKEINT
WDHALT
Low Power
Modes Block
WDHALTI
(ignore HALT)
XRS
TZ5
CLOCKFAIL
CLKCTL Reg
ePWM1.../ePWMx
VREGHALT
VREG
NORMRDY
GPIO
Mux
PIE
LPMINT
WAKEOSC
HALT
STANDBY
WDRST
WDCLK
XCLKIN
X1 (Vcore)
X2 (Vcore)
CLOCKFAIL
Internal
CPUTMR2CLK
&
OSCCLK
External
Oscillators
CPU Timer2
NMI
WD
NMIRS
PLLDIS
(used in device test mode)
WAKEOSC
OSCCLK
0
NMI
SYSCLKOUT
CLKIN
PLLDIS (turn off when 0, used in device test mode)
PLLSTS[PLLOFF]
(turn off when 1)
PLLCLK
PLLLOCKPRD Reg
VCOCLK
(OSCCLK * PLLCR ratio)
PLL
res
clk
PLLSTS[OSCOFF]
VCOCLK
Counter
(13 bits)
clear clear
1
DIVSEL
(/4 on reset)
PLLLOCKS
MCLKOFF
(turn off when 1)
NORMRDYE
MCLKSTS
MCLKCLR
clear
PLL Clock
Counter
clk
ovf
(17 bits)
1
Clock
Switch
Logic
/1,
/2,
/4
off
ovf
PLLSTS
Reg
C28
Core
PLLCR Reg
GPIO
Mux
res
0
clear
XCLKOUT
OSCCLK
Counter
clk (7 Bits) ovf
clear clear
MCLKRES
res
XCLK Reg
/1, /2,
/4, off
SYSCLKOUT
Sync
XRS
If the OSCCLK input signal is missing, then the PLL will output a default limp mode frequency and the
VCOCLK counter will continue to increment. Since the OSCCLK signal is missing, the OSCCLK counter
will not increment and, therefore, the VCOCLK counter is not periodically cleared. Eventually, the
VCOCLK counter overflows and, if required, the device switches the CLKIN input to the CPU to the limp
mode output frequency of the PLL.
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When the VCOCLK counter overflows, the missing clock detection logic resets the CPU, peripherals, and
other device logic. The reset generated is known as a missing clock detect logic reset (MCLKRS). The
MCLKRS is an internal reset only. The external XRS pin of the device is not pulled low by MCLKRS and
the PLLCR and PLLSTS registers are not reset. This is the default behavior at reset.
In addition to resetting the device, the missing oscillator logic sets the PLLSTS[MCLKSTS] register bit.
When the MCLKCSTS bit is 1, this indicates that the missing oscillator detect logic has reset the part and
that the CPU is now running at the limp mode frequency.
Software should check the PLLSTS[MCLKSTS] bit after a reset to determine if the device was reset by
MCLKRS due to a missing clock condition. If MCLKSTS is set, then the firmware should take the action
appropriate for the system such as a system shutdown. The missing clock status can be cleared by writing
a 1 to the PLLSTS[MCLKCLR] bit. This will reset the missing clock detection circuits and counters. If
OSCCLK is still missing after writing to the MCLKCLR bit, then the VCOCLK counter again overflows and
the process will repeat.
NOTE: Applications in which the correct CPU operating frequency is absolutely critical should
implement a mechanism by which the device will be held in reset should the input clocks
ever fail. For example, an R-C circuit may be used to trigger the XRS pin of the device
should the capacitor ever get fully charged. An I/O pin may be used to discharge the
capacitor on a periodic basis to prevent it from getting fully charged. Such a circuit would
also help in detecting failure of the flash memory.
The following precautions and limitations should be kept in mind:
• Use the proper procedure when changing the PLL Control Register. Always follow the procedure
outlined in Figure 26 when modifying the PLLCR register.
• Do not write to the PLLCR register when the device is operating in limp mode. When writing to
the PLLCR register, the device switches to the CPU's CLKIN input to OSCCLK/2. When operating after
limp mode has been detected, OSCCLK may not be present and the clocks to the system will stop.
Always check that the PLLSTS[MCLKSTS] bit = 0 before writing to the PLLCR register as described in
Figure 26.
• The watchdog is not functional without an external clock. The watchdog is not functional and
cannot generate a reset when OSCCLK is not present. No special hardware has been added to switch
the watchdog to the limp mode clock should OSCCLK become missing.
• Do not enter HALT low power mode when the device is operating in limp mode.If you try to enter
HALT mode when the device is already operating in limp mode then the device may not properly enter
HALT. The device may instead enter STANDBY mode or may hang and you may not be able to exit
HALT mode. For this reason, always check that the PLLSTS[MCLKSTS] bit = 0 before entering HALT
mode.
The following list describes the behavior of the missing clock detect logic in various operating modes:
• PLL by-pass mode
When the PLL control register is set to 0x0000, the PLL is by-passed. Depending on the state of the
PLLSTS[DIVSEL] bit, OSCCLK, OSCCLK/2, or OSCCLK/4 is connected directly to the CPU's input
clock, CLKIN. If the OSCCLK is detected as missing, the device will automatically switch to the PLL,
set the missing clock detect status bit, and generate a missing clock reset. The device will now run at
the PLL limp mode frequency or one-half of the PLL limp mode frequency.
• PLL enabled mode
When the PLL control register is non-zero (PLLCR = n, where n ≠ 0x0000), the PLL is enabled. In this
mode, OSCCLK*n, OSCCLK*n/2, or OSCCLK*n/4 is connected to CLKIN of the CPU. If OSCCLK is
detected as missing, the missing clock detect status bit will be set and the device will generate a
missing clock reset. The device will now run at one-half of the PLL limp mode frequency.
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•
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STANDBY low power mode
In this mode, the CLKIN to the CPU is stopped. If a missing input clock is detected, the missing clock
status bit will be set and the device will generate a missing clock reset. If the PLL is in by-pass mode
when this occurs, then one-half of the PLL limp frequency will automatically be routed to the CPU. The
device will now run at the PLL limp mode frequency or at one-half or one-fourth of the PLL limp mode
frequency, depending on the state of the PLLSTS[DIVSEL] bit.
HALT low power mode
In HALT low power mode, all of the clocks to the device are turned off. When the device comes out of
HALT mode, the oscillator and PLL will power up. The counters that are used to detect a missing input
clock (VCOCLK and OSCCLK) will be enabled only after this power-up has completed. If VCOCLK
counter overflows, the missing clock detect status bit will be set and the device will generate a missing
clock reset. If the PLL is in by-pass mode when the overflow occurs, then one-half of the PLL limp
frequency will automatically be routed to the CPU. The device will now run at the PLL limp mode
frequency or at one-half or one-fourth of the PLL limp mode frequency depending on the state of the
PLLSTS[DIVSEL] bit.
NMI Interrupt and Watchdog
The NMI watchdog (NMIWD) is used to detect and aid in recovery from a clock failure condition. The NMI
interrupt enables the monitoring of the erroneous CLOCKFAIL condition in the system. In
280x/2833x/2823x devices, when a missing clock is detected, a missing-clock-reset (MCLKRS) is
generated immediately. In Piccolo devices however, a CLOCKFAIL signal can be generated first, which is
then fed to the NMI Watchdog circuit and a reset is generated after a preprogrammed delay. This feature
is not enabled upon power-up, however. That is, when Piccolo first powers up, the MCLKRS signal is
generated immediately upon clock failure like other 28xx devices. The user must enable the generation of
the CLOCKFAIL signal via the CLKCTL[NMIRESETSEL] bit. Note that the NMI watchdog is different from
the watchdog described in Section 3.4.
When the OSCCLK goes missing, the CLOCKFAIL signal triggers the NMI and gets the NMIWD counter
running. In the NMI ISR, the application is expected to take corrective action (such as switch to an
alternate clock source) and clear the CLOCKFAIL and NMIINT flags. If this is not done, the NMIWDCTR
overflows and generates an NMI reset (NMIRS) after a preprorammed number of SYSCLKOUT cycles.
NMIRS is fed to MCLKRS to generate a system reset back into the core. The purpose of this is to allow
software to gracefully shut down the system before a reset is generated. Note that NMI reset will not be
reflected on the XRS pin and is internal to the device.
The CLOCKFAIL signal could also be used to activate the TZ5 signal to drive the PWM pins into a high
impedance state. This allows the PWM outputs to be tripped in case of clock failure. Figure 24 shows the
CLOCKFAIL interrupt mechanism. Likewise, TZ6 is connected to EMUSTOP output from the CPU. This
allows the user to configure trip action during a CPU halt, such as during emulation or debug sessions.
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Figure 24. Clock Fail Interrupt
NMIFLG[NMINT]
NMIFLGCLR[NMINT]
Clear
Latch
Set Clear
XRS
Generate
Interrupt
Pulse
When
Input = 1
NMINT
1
NMIFLG[CLOCKFAIL]
0
Clear
NMIFLGCLR[CLOCKFAIL]
CLOCKFAIL
SYNC?
SYSCLKOUT
Latch
Clear Set
0
NMICFG[CLOCKFAIL]
NMIFLGFRC[CLOCKFAIL]
XRS
SYSCLKOUT
SYSRS
NMIWDPRD[15:0]
NMIWDCNT[15:0]
A
NMI Watchdog
NMIRS
See System
Control Section
The NMI watchdog module is clocked by SYSCLKOUT. Due to the limp mode function of the PLL, SYSCLKOUT is
present even if the source clock for OSCCLK fails.
The NMI Interrupt support registers are listed in Table 23.
Table 23. NMI Interrupt Registers
Name
Address Range
Size (x16)
EALLOW
Description
NMICFG
0x7060
1
yes
NMI Configuration Register
NMIFLG
0x7061
1
yes
NMI Flag Register
NMIFLGCLR
0x7062
1
yes
NMI Flag Clear Register
NMIFLGFRC
0x7063
1
yes
NMI Flag Force Register
NMIWDCNT
0x7064
1
-
NMIWDPRD
0x7065
1
yes
NMI Watchdog Counter Register
NMI Watchdog Period Register
Table 24. NMI Configuration (NMICFG) Register Bit Definitions (EALLOW)
Bits Name
Type
15:2 Reserved
1
0
Any writes to these bit(s) must always have a value of 0.
CLOCKFAIL
Reserved
Description
CLOCKFAIL-interrupt Enable Bit: This bit, when set to 1 enables the CLOCKFAIL condition to
generate an NMI interrupt. Once enabled, the flag cannot be cleared by the user. Only a device
reset clears the flag. Writes of 0 are ignored. Reading the bit will indicate if the flag is enabled or
disabled:
0
CLOCKFAIL Interrupt Disabled
1
CLOCKFAIL Interrupt Enabled
Any writes to these bit(s) must always have a value of 0.
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Table 25. NMI Flag (NMIFLG) Register Bit Definitions (EALLOW Protected):
Bits
Name
15:2
Reserved
Any writes to these bit(s) must always have a value of 0.
CLOCKFAIL
CLOCKFAIL Interrupt Flag: This bit indicates if the CLOCKFAIL condition is latched. This bit can
be cleared only by writing to the respective bit in the NMIFLGCLR register or by a device reset
(XRS):
1
0
Type Description
0
No CLOCKFAIL condition pending
1
CLOCKFAIL condition detected. This bit will be set in the event of any clock failure.
NMIINT
NMI Interrupt Flag: This bit indicates if an NMI interrupt was generated. This bit can only be
cleared by writing to the respective bit in the NMIFLGCLR register or by an XRS reset:
0
No NMI interrupt generated
1
NMI interrupt generated
No further NMI interrupts are generated until you clear this flag.
Table 26. NMI Flag Clear (NMIFLGCLR) Register Bit Definitions (EALLOW Protected)
Bits
Name
15:2
Reserved
Any writes to these bit(s) must always have a value of 0.
CLOCKFAIL (1)
1
CLOCKFAIL Flag Clear
0
Writes of 0 are ignored. Always reads back 0.
1
Writing a 1 to the respective bit clears the corresponding flag bit in the NMIFLG register.
NMIINT (1)
0
(1)
Type Description
NMI Flag Clear
0
Writes of 0 are ignored. Always reads back 0.
1
Writing a 1 to the respective bit clears the corresponding flag bit in the NMIFLG register.
If hardware is trying to set a bit to 1 while software is trying to clear a bit to 0 on the same cycle, hardware has priority. You
should clear the pending CLOCKFAIL flag first and then clear the NMIINT flag.
Table 27. NMI Flag Force (NMIFLGFRC) Register Bit Definitions (EALLOW Protected):
Bits
15:02
1
0
Name
Value
Reserved
Description
Any writes to these bit(s) must always have a value of 0.
CLOCKFAIL
CLOCKFAIL flag force
0
Writes of 0 are ignored. Always reads back 0. This can be used as a means to test the NMI
mechanisms.
1
Writing a 1 sets the CLOCKFAIL flag.
Reserved
Any writes to these bit(s) must always have a value of zero.
Table 28. NMI Watchdog Counter (NMIWDCNT) Register Bit Definitions
Bits
Name
15:0
NMIWDCNT
Type
Description
NMI Watchdog Counter: This 16-bit incremental counter will start incrementing whenever any
one of the enabled FAIL flags are set. If the counter reaches the period value, an NMIRS
signal is fired, which then resets the system. The counter resets to zero when it reaches the
period value and then restarts counting if any of the enabled FAIL flags are set.
0
If no enabled FAIL flag is set, then the counter resets to zero and remains at zero until an
enabled FAIL flag is set.
1
Normally, the software would respond to the NMI interrupt generated and clear the offending
FLAGs before the NMI watchdog triggers a reset. In some situations, the software may decide
to allow the watchdog to reset the device anyway.
The counter is clocked at the SYSCLKOUT rate. Reset value of this counter is zero.
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Table 29. NMI Watchdog Period () Register Bit Definitions (EALLOW Protected)
3.2.6.1
Bits
Name
Type
Description
15:0
NMIWDPRD
R/W
NMI Watchdog Period: This 16-bit value contains the period value at which a reset is
generated when the watchdog counter matches. At reset this value is set at the maximum.
The software can decrease the period value at initialization time.
Writing a PERIOD value that is equal to the current counter value automatically forces an
NMIRS and resets the watchdog counter. If a PERIOD value is written that is smaller than the
current counter value, the counter will continue counting until it overflows and starts counting
up again from 0. After the overflow, once the COUNTER value equals the new PERIOD
value, an NMIRS is forced which resets the watchdog counter.
NMI Watchdog Emulation Considerations
The NMI watchdog module does not operate when trying to debug the target device (emulation suspend
such as breakpoint). The NMI watchdog module behaves as follows under various debug conditions:
CPU Suspended:
Run-Free Mode:
Real-Time Single-Step
Mode:
Real-Time Run-Free
Mode:
When the CPU is suspended, the NMI watchdog counter is suspended.
When the CPU is placed in run-free mode, the NMI watchdog counter
resumes operation as normal.
When the CPU is in real-time single-step mode, the NMI watchdog
counter is suspended. The counter remains suspended even within
real-time interrupts.
When the CPU is in real-time run-free mode, the NMI watchdog counter
operates as normal.
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XCLKOUT Generation
The XCLKOUT signal is directly derived from the system clock SYSCLKOUT as shown in Figure 25.
XCLKOUT can be either equal to, one-half, or one-fourth of SYSCLKOUT. By default, at power-up,
XCLKOUT = SYSCLKOUT/4 or XCLKOUT = OSCCLK/16.
Figure 25. XCLKOUT Generation
/4
PLL Bypass
OSCCLK
/2
0
0
or
1
2
CLKIN
3
n
PLL
/4
0,0
/2
0,1
28x CPU
SYSCLKOUT
1,0
XCLKOUT
Pin
n≠0
PLLCR
PLLSTS[DIVSEL]
XCLK[XCLKOUTDIV]
Default at reset
If XCLKOUT is not being used, it can be turned off by setting the XCLKOUTDIV bit to 3 in the XCLK
register.
3.2.8
PLL Control (PLLCR) Register
The PLLCR register is used to change the PLL multiplier of the device. Before writing to the PLLCR
register, the following requirements must be met:
• The PLLSTS[DIVSEL] bit must be 0 (CLKIN divide by 4 enabled). Change PLLSTS[DIVSEL] only after
the PLL has completed locking, that is, after PLLSTS[PLLLOCKS] = 1.
Once the PLL is stable and has locked at the new specified frequency, the PLL switches CLKIN to the
new value as shown in Table 30. When this happens, the PLLLOCKS bit in the PLLSTS register is set,
indicating that the PLL has finished locking and the device is now running at the new frequency. User
software can monitor the PLLLOCKS bit to determine when the PLL has completed locking. Once
PLLSTS[PLLLOCKS] = 1, DIVSEL can be changed.
Follow the procedure in Figure 26 any time you are writing to the PLLCR register.
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Figure 26. PLLCR Change Procedure Flow Chart
Start
PLLSTS[MCLKSTS]
= 1?
Yes
No
Device is operating in limp
mode. Take appropriate
action for your system.
Do not write to PLLCR.
Yes
Set PLLSTS[DIVSEL] = 0
PLLSTS[DIVSEL]
= 2 or 3?
No
Set PLLSTS[MCLKOFF] = 1
to disable failed oscillator
detect logic
Set new PLLCR value
Is
PLLSTS[PLLLOCKS]
= 1?
No
Continue to wait for PLL
to lock. This is important
for time-critical software.
Yes
Set PLL[MCLKOFF] = 0
to enable failed oscillator
detect logic.
If required,
PLLSTS [DIVSEL]
can now be changed.
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PLL Control, Status and XCLKOUT Register Descriptions
The DIV field in the PLLCR register controls whether the PLL is bypassed or not and sets the PLL
clocking ratio when it is not bypassed. PLL bypass is the default mode after reset. Do not write to the DIV
field if the PLLSTS[DIVSEL] bit is 10 or 11, or if the PLL is operating in limp mode as indicated by the
PLLSTS[MCLKSTS] bit being set. See the procedure for changing the PLLCR described in Figure 26.
Figure 27. PLLCR Register Layout
15
4
3
0
Reserved
DIV
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 30. PLL Settings (1)
SYSCLKOUT (CLKIN)
PLLCR[DIV] Value
(1)
(3)
(2)
PLLSTS[DIVSEL] = 0 or 1
PLLSTS[DIVSEL] = 2
0000 (PLL bypass)
OSCCLK/4 (Default)
OSCCLK/2
PLLSTS[DIVSEL] = 3
OSCCLK/1
0001
(OSCCLK * 1)/4
(OSCCLK * 1)/2
(OSCCLK * 1)/1
0010
(OSCCLK * 2)/4
(OSCCLK * 2)/2
(OSCCLK * 2)/1
0011
(OSCCLK * 3)/4
(OSCCLK * 3)/2
(OSCCLK * 3)/1
0100
(OSCCLK * 4)/4
(OSCCLK * 4)/2
(OSCCLK * 4)/1
0101
(OSCCLK * 5)/4
(OSCCLK * 5)/2
(OSCCLK * 5)/1
0110
(OSCCLK * 6)/4
(OSCCLK * 6)/2
(OSCCLK * 6)/1
0111
(OSCCLK * 7)/4
(OSCCLK * 7)/2
(OSCCLK * 7)/1
1000
(OSCCLK * 8)/4
(OSCCLK * 8)/2
(OSCCLK * 8)/1
1001
(OSCCLK * 9)/4
(OSCCLK * 9)/2
(OSCCLK * 9)/1
1010
(OSCCLK * 10)/4
(OSCCLK * 10)/2
(OSCCLK * 10)/1
1011
(OSCCLK * 11)/4
(OSCCLK * 11)/2
(OSCCLK * 11)/1
1100
(OSCCLK * 12)/4
(OSCCLK * 12)/2
(OSCCLK * 12)/1
1101-1111
Reserved
Reserved
Reserved
This register is EALLOW protected. See Section 5.2 for more information.
PLLSTS[DIVSEL] must be 0 or 1 before writing to the PLLCR and should be changed only after PLLSTS[PLLLOCKS] = 1. See
Figure 26.
The PLL control register (PLLCR) and PLL Status Register (PLLSTS) are reset to their default state by the XRS signal or a
watchdog reset only. A reset issued by the debugger or the missing clock detect logic have no effect.
(2)
(3)
Figure 28. PLL Status Register (PLLSTS)
15
14
9
8
NORMRDYE
Reserved
DIVSEL
R/W-0
R-0
R/W-0
7
6
5
4
3
2
1
0
DIVSEL
MCLKOFF
OSCOFF
MCLKCLR
MCLKSTS
PLLOFF
Reserved
PLLLOCKS
R/W-0
R/W-0
R/W-0
R/W-0
R-0
R/W-0
R-0
R-1
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 31. PLL Status Register (PLLSTS) Field Descriptions
Bits
15
(1)
(2)
50
Field
NORMRDYE
Value
Description
(1) (2)
NORMRDY Enable Bit: This bit selects if NORMRDY signal from VREG gates the PLL from turning
on when the VREG is out of regulation. It may be required to keep the PLL off while coming in and
out of HALT mode and this signal can be used for that purpose:
This register is reset to its default state only by the XRS signal or a watchdog reset. It is not reset by a missing clock or debugger reset.
This register is EALLOW protected. See Section 5.2 for more information.
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Table 31. PLL Status Register (PLLSTS) Field Descriptions (continued)
Bits
Field
Value
Description
(1) (2)
0
NORMRDY signal from VREG does not gate PLL (PLL ignores NORMRDY)
1
NORMRDY signal from VREG will gate PLL (PLL off when NORMRDY low)
The NORMRDY signal from the VREG is low when the VREG is out of regulation and this signal
will go high if the VREG is within regulation.
14-9
Reserved
Any writes to these bit(s) must always have a value of 0.
8:7
DIVSEL
Divide Select: This bit selects between /4, /2, and /1 for CLKIN to the CPU.
The configuration of the DIVSEL bit is as follows:
6
5
00, 01
Select Divide By 4 for CLKIN
10
Select Divide By 2 for CLKIN
11
Select Divide By 1 for CLKIN. (This mode can be used only when PLL is off or bypassed.)
MCLKOFF
Missing clock-detect off bit
0
Main oscillator fail-detect logic is enabled. (default)
1
Main oscillator fail-detect logic is disabled and the PLL will not issue a limp-mode clock. Use this
mode when code must not be affected by the detection circuit. For example, if external clocks are
turned off.
OSCOFF
Oscillator Clock Off Bit
0
The OSCCLK signal from X1/X2 or XCLKIN is fed to the PLL block. (default)
1
The OSCCLK signal from X1/X2 or XCLKIN is not fed to the PLL block. This does not shut down
the internal oscillator. The OSCOFF bit is used for testing the missing clock detection logic.
When the OSCOFF bit is set, do not enter HALT or STANDBY modes or write to PLLCR as these
operations can result in unpredictable behavior.
When the OSCOFF bit is set, the behavior of the watchdog is different depending on which input
clock source (X1, X1/X2 or XCLKIN) is being used:
• X1/X2: The watchdog is not functional.
• XCLKIN: The watchdog is functional and should be disabled before setting OSCOFF.
4
3
MCLKCLR
Missing Clock Clear Bit.
0
Writing a 0 has no effect. This bit always reads 0.
1
Forces the missing clock detection circuits to be cleared and reset. If OSCCLK is still missing, the
detection circuit will again generate a reset to the system, set the missing clock status bit
(MCLKSTS), and the CPU will be clocked by the PLL operating at a limp mode frequency.
MCLKSTS
Missing Clock Status Bit. Check the status of this bit after a reset to determine whether a missing
oscillator condition was detected. Under normal conditions, this bit should be 0. Writes to this bit
are ignored. This bit will be cleared by writing to the MCLKCLR bit or by forcing an external reset.
0
Indicates normal operation. A missing clock condition has not been detected.
1
Indicates that OSCCLK was detected as missing. The main oscillator fail detect logic has reset the
device and the CPU is now clocked by the PLL operating at the limp mode frequency.
When the missing clock detection circuit automatically switches between OSCCLKSRC2 to
OSCCLKSRC1 (upon detecting OSCCLKSRC2 failure), this bit will be automatically cleared and
the missing clock detection circuit will be re-enabled. For all other cases, the user needs to reenable this mode by writing a 1 to the MCLKCLR bit.
2
PLLOFF
PLL Off Bit. This bit turns off the PLL. This is useful for system noise testing. This mode must only
be used when the PLLCR register is set to 0x0000.
0
PLL On (default)
1
PLL Off. While the PLLOFF bit is set the PLL module will be kept powered down.
The device must be in PLL bypass mode (PLLCR = 0x0000) before writing a 1 to PLLOFF. While
the PLL is turned off (PLLOFF = 1), do not write a non-zero value to the PLLCR.
The STANDBY and HALT low power modes will work as expected when PLLOFF = 1. After waking
up from HALT or STANDBY the PLL module will remain powered down.
1
Reserved
Any writes to these bit(s) must always have a value of 0.
0
PLLLOCKS
PLL Lock Status Bit.
0
Indicates that the PLLCR register has been written to and the PLL is currently locking. The CPU is
clocked by OSCCLK/2 until the PLL locks.
1
Indicates that the PLL has finished locking and is now stable.
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Figure 29. PLL Lock Period (PLLLOCKPRD) Register
15
0
PLLLOCKPRD
R/W-FFFFh
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 32. PLL Lock Period (PLLLOCKPRD) Register Field Descriptions
Bit
15:0
Field
Value
PLLLOCKPRD
(2)
(1) (2)
PLL Lock Counter Period Value
0
These 16-bits select the PLL lock counter period. This value is programmable, so shorter PLL locktime can be programmed by user. The user needs to compute the number of OSCCLK cycles
(based on the OSCCLK value used in the design) and update this register.
1
PLL Lock Period
FFFFh
65535 OSCLK Cycles (default on reset)
FFFEh
65534 OSCLK Cycles
...
(1)
Description
...
0001h
1 OSCCLK Cycles
0000h
0 OSCCLK Cycles (no PLL lock period)
PLLLOCKPRD is affected by XRSn signal only.
This register is EALLOW protected. See Section 5.2 for more information.
3.2.10
External Reference Oscillator Clock Option
TI recommends that customers have the resonator/crystal vendor characterize the operation of their
device with the device chip. The resonator/crystal vendor has the equipment and expertise to tune the
tank circuit. The vendor can also advise the customer regarding the proper tank component values to
provide proper start-up and stability over the entire operating range.
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3.3
Low-Power Modes Block
Table 33 summarizes the various modes.
The various low-power modes operate as shown in Table 34.
See the TMS320F2802x Microcontrollers (MCUs) Data Manual (literature number SPRS523 ) for exact
timing for entering and exiting the low power modes.
Table 33. Low-Power Mode Summary
(1)
(2)
Exit
(1)
Mode
LPMCR0[1:0]
OSCCLK
CLKIN
SYSCLKOUT
IDLE
00
On
On
On
XRS,
Watchdog interrupt,
Any enabled interrupt
STANDBY
01
On
(watchdog still running)
Off
Off
XRS,
Watchdog interrupt,
GPIO Port A signal,
Debugger (2)
HALT
1X
Off
(oscillator and PLL turned off,
watchdog not functional)
Off
Off
XRS,
GPIO Port A Signal,
Debugger (2)
The Exit column lists which signals or under what conditions the low power mode is exited. This signal must be kept low long enough for
an interrupt to be recognized by the device. Otherwise the IDLE mode is not exited and the device goes back into the indicated low
power mode.
On the 28x, the JTAG port can still function even if the clock to the CPU (CLKIN) is turned off.
Table 34. Low Power Modes
Mode
Description
IDLE
Mode:
This mode is exited by any enabled interrupt. The LPM block itself performs no tasks during this mode.
STANDBY
Mode:
If the LPM bits in the LPMCR0 register are set to 01, the device enters STANDBY mode when the IDLE instruction is
executed. In STANDBY mode the clock input to the CPU (CLKIN) is disabled, which disables all clocks derived from
SYSCLKOUT. The oscillator and PLL and watchdog will still function. Before entering the STANDBY mode, you should
perform the following tasks:
• Enable the WAKEINT interrupt in the PIE module. This interrupt is connected to both the watchdog and the low
power mode module interrupt.
• If desired, specify one of the GPIO port A signals to wake the device in the GPIOLPMSEL register. The
GPIOLPMSEL register is part of the GPIO module. In addition to the selected GPIO signal, the XRS input and the
watchdog interrupt, if enabled in the LPMCR0 register, can wake the device from the STANDBY mode.
• Select the input qualification in the LPMCR0 register for the signal that will wake the device.
When the selected external signal goes low, it must remain low a number of OSCCLK cycles as specified by the
qualification period in the LPMCR0 register. If the signal should be sampled high during this time, the qualification will
restart. At the end of the qualification period, the PLL enables the CLKIN to the CPU and the WAKEINT interrupt is
latched in the PIE block. The CPU then responds to the WAKEINT interrupt if it is enabled.
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Table 34. Low Power Modes (continued)
Mode
HALT
Mode:
Description
If the LPM bits in the LPMCR0 register are set to 1x, the device enters the HALT mode when the IDLE instruction is
executed. In HALT mode all of the device clocks, including the PLL and oscillator, are shut down. Before entering the
HALT mode, you should perform the following tasks:
• Enable the WAKEINT interrupt in the PIE module (PIEIER1.8 = 1). This interrupt is connected to both the
watchdog and the Low-Power-Mode module interrupt.
• Specify one of the GPIO port A signals to wake the device in the GPIOLPMSEL register. The GPIOLPMSEL
register is part of the GPIO module. In addition to the selected GPIO signal, the XRS input can also wake the
device from the HALT mode.
• Disable all interrupts with the possible exception of the HALT mode wakeup interrupt. The interrupts can be reenabled after the device is brought out of HALT mode.
1.
For device to exit HALT mode properly, the following conditions must be met:
Bit 7 (INT1.8) of PIEIER1 register should be 1.
Bit 0 (INT1) of IER register must be 1.
2.
If the above conditions are met,
(a) WAKE_INT ISR will be executed first, followed by the instructions after IDLE, if INTM =
0.
(b) WAKE_INT ISR will not be executed and instructions after IDLE will be executed, if
INTM = 1.
Do not enter HALT low power mode when the device is operating in limp mode (PLLSTS[MCLKSTS] = 1).
If you try to enter HALT mode when the device is already operating in limp mode then the device may not properly enter
HALT. The device may instead enter STANDBY mode or may hang and you may not be able to exit HALT mode. For
this reason, always check that the PLLSTS[MCLKSTS] bit = 0 before entering HALT mode.
When the selected external signal goes low, it is fed asynchronously to the LPM block. The oscillator is turned on and
begins to power up. You must hold the signal low long enough for the oscillator to complete power up. When the signal
is held low for enough time and driven high, this will asynchronously release the PLL and it will begin to lock. Once the
PLL has locked, it feeds the CLKIN to the CPU at which time the CPU responds to the WAKEINT interrupt if enabled.
The low-power modes are controlled by the LPMCR0 register (Figure 30).
Figure 30. Low Power Mode Control 0 Register (LPMCR0)
15
14
8
7
2
1
0
WDINTE
Reserved
QUALSTDBY
LPM
R/W-0
R-0
R/W-0x3F
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 35. Low Power Mode Control 0 Register (LPMCR0) Field Descriptions
Bits
15
Field
Value
WDINTE
0
The watchdog interrupt is not allowed to wake the device from STANDBY. (default)
1
The watchdog is allowed to wake the device from STANDBY. The watchdog interrupt must also
be enabled in the SCSR Register.
14-8
Reserved
Any writes to these bit(s) must always have a value of 0.
7-2
QUALSTDBY
Select number of OSCCLK clock cycles to qualify the selected GPIO inputs that wake the device
from STANDBY mode. This qualification is only used when in STANDBY mode. The GPIO
signals that can wake the device from STANDBY are specified in the GPIOLPMSEL register.
000000
2 OSCCLKs
000001
3 OSCCLKs
111111
54
(1)
Watchdog interrupt enable
...
(1)
Description
...
65 OSCCLKs (default)
This register is EALLOW protected. See Section 5.2 for more information.
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Table 35. Low Power Mode Control 0 Register (LPMCR0) Field Descriptions (continued)
Bits
1-0
(2)
(3)
Field
LPM
Value
(2)
Description
(1)
These bits set the low power mode for the device.
00
Set the low power mode to IDLE (default)
01
Set the low power mode to STANDBY
10
Set the low power mode to HALT
(3)
11
Set the low power mode to HALT
(3)
The low power mode bits (LPM) only take effect when the IDLE instruction is executed. Therefore, you must set the LPM bits to the
appropriate mode before executing the IDLE instruction.
If you try to enter HALT mode when the device is already operating in limp mode then the device may not properly enter HALT. The
device may instead enter STANDBY mode or may hang and you may not be able to exit HALT mode. For this reason, always check that
the PLLSTS[MCLKSTS] bit = 0 before entering HALT mode.
3.3.1
Options for Automatic Wakeup in Low-power Modes
The device provides two options to automatically wake up from HALT and STANDBY modes, without the
need for an external stimulus:
Wakeup from HALT: Set WDHALTI bit in CLKCTL register to 1. When the device wakes up from HALT, it
will be through a CPU-watchdog reset. The WDFLAG bit in the WDCR register can be used to differentiate
between a CPU-watchdog-reset and a device reset.
Wakeup from STANDBY: Set WDINTE bit in LPMCR0 register to 1. When the device wakes up from
STANDBY, it will be through the WAKEINT interrupt (Interrupt 1.8 in the PIE).
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CPU Watchdog Block
The watchdog module generates an output pulse, 512 oscillator-clocks (OSCCLK) wide whenever the 8bit watchdog up counter has reached its maximum value. To prevent this, the user can either disable the
counter or the software must periodically write a 0x55 + 0xAA sequence into the watchdog key register
which resets the watchdog counter. Figure 31 shows the various functional blocks within the watchdog
module.
Figure 31. CPU Watchdog Module
WDCR (WDPS(2:0))
WDCR (WDDIS)
WDCNTR(7:0)
OSCCLK
Watchdog
Prescaler
/512
WDCLK
8-Bit
Watchdog
Counter
CLR
Clear Counter
Internal
Pullup
WDKEY(7:0)
Watchdog
55 + AA
Key Detector
WDRST
Generate
Output Pulse
WDINT
(512 OSCCLKs)
Good Key
XRS
Core-reset
WDCR (WDCHK(2:0))
WDRST(A)
A
56
1
0
Bad
WDCHK
Key
SCSR (WDENINT)
1
The WDRST and XRS signals are driven low for 512 OSCCLK cycles when a watchdog reset occurs. Likewise, if the
watchdog interrupt is enabled, the WDINT signal will be driven low for 512 OSCCLK cycles when an interrupt occurs.
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3.4.1
Servicing The Watchdog Timer
The WDCNTR is reset when the proper sequence is written to the WDKEY register before the 8-bit
watchdog counter (WDCNTR) overflows. The WDCNTR is reset-enabled when a value of 0x55 is written
to the WDKEY. When the next value written to the WDKEY register is 0xAA then the WDCNTR is reset.
Any value written to the WDKEY other than 0x55 or 0xAA causes no action. Any sequence of 0x55 and
0xAA values can be written to the WDKEY without causing a system reset; only a write of 0x55 followed
by a write of 0xAA to the WDKEY resets the WDCNTR.
Table 36. Example Watchdog Key Sequences
Step
Value Written to WDKEY
1
0xAA
No action
Result
2
0xAA
No action
3
0x55
WDCNTR is enabled to be reset if next value is 0xAA.
4
0x55
WDCNTR is enabled to be reset if next value is 0xAA.
5
0x55
WDCNTR is enabled to be reset if next value is 0xAA.
6
0xAA
WDCNTR is reset.
7
0xAA
No action
8
0x55
WDCNTR is enabled to be reset if next value is 0xAA.
9
0xAA
WDCNTR is reset.
10
0x55
WDCNTR is enabled to be reset if next value is 0xAA.
11
0x32
Improper value written to WDKEY.
No action, WDCNTR no longer enabled to be reset by next 0xAA.
12
0xAA
No action due to previous invalid value.
13
0x55
WDCNTR is enabled to be reset if next value is 0xAA.
14
0xAA
WDCNTR is reset.
Step 3 in Table 36 is the first action that enables the WDCNTR to be reset. The WDCNTR is not actually
reset until step 6. Step 8 again re-enables the WDCNTR to be reset and step 9 resets the WDCNTR. Step
10 again re-enables the WDCNTR ro be reset. Writing the wrong key value to the WDKEY in step 11
causes no action, however the WDCNTR is no longer enabled to be reset and the 0xAA in step 12 now
has no effect.
If the watchdog is configured to reset the device, then a WDCR overflow or writing the incorrect value to
the WDCR[WDCHK] bits will reset the device and set the watchdog flag (WDFLAG) in the WDCR register.
After a reset, the program can read the state of this flag to determine the source of the reset. After reset,
the WDFLAG should be cleared by software to allow the source of subsequent resets to be determined.
Watchdog resets are not prevented when the flag is set.
3.4.2
Watchdog Reset or Watchdog Interrupt Mode
The watchdog can be configured in the SCSR register to either reset the device (WDRST) or assert an
interrupt (WDINT) if the watchdog counter reaches its maximum value. The behavior of each condition is
described below:
• Reset mode:
If the watchdog is configured to reset the device, then the WDRST signal will pull the device reset
(XRS) pin low for 512 OSCCLK cycles when the watchdog counter reaches its maximum value.
• Interrupt mode:
If the watchdog is configured to assert an interrupt, then the WDINT signal will be driven low for 512
OSCCLK cycles, causing the WAKEINT interrupt in the PIE to be taken if it is enabled in the PIE
module. The watchdog interrupt is edge triggered on the falling edge of WDINT. Thus, if the WAKEINT
interrupt is re-enabled before WDINT goes inactive, you will not immediately get another interrupt. The
next WAKEINT interrupt will occur at the next watchdog timeout.
If the watchdog is re-configured from interrupt mode to reset mode while WDINT is still active low, then
the device will reset immediately. The WDINTS bit in the SCSR register can be read to determine the
current state of the WDINT signal before reconfiguring the watchdog to reset mode.
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Watchdog Operation in Low Power Modes
In STANDBY mode, all of the clocks to the peripherals are turned off on the device. The only peripheral
that remains functional is the watchdog since the watchdog module runs off the oscillator clock
(OSCCLK). The WDINT signal is fed to the Low Power Modes (LPM) block so that it can be used to wake
the device from STANDBY low power mode (if enabled). See the Low Power Modes Block section of the
device data manual for details.
In IDLE mode, the watchdog interrupt (WDINT) signal can generate an interrupt to the CPU to take the
CPU out of IDLE mode. The watchdog is connected to the WAKEINT interrupt in the PIE.
NOTE:
If the watchdog interrupt is used to wake-up from an IDLE or STANDBY low power mode
condition, then make sure that the WDINT signal goes back high again before attempting to
go back into the IDLE or STANDBY mode. The WDINT signal will be held low for 512
OSCCLK cycles when the watchdog interrupt is generated. You can determine the current
state of WDINT by reading the watchdog interrupt status bit (WDINTS) bit in the SCSR
register. WDINTS follows the state of WDINT by two SYSCLKOUT cycles.
In HALT mode, this feature cannot be used because the oscillator (and PLL) are turned off and, therefore,
so is the watchdog.
3.4.4
Emulation Considerations
The watchdog module behaves as follows under various debug conditions:
CPU Suspended:
Run-Free Mode:
Real-Time Single-Step
Mode:
Real-Time Run-Free
Mode:
58
System Control
When the CPU is suspended, the watchdog clock (WDCLK) is suspended
When the CPU is placed in run-free mode, then the watchdog module
resumes operation as normal.
When the CPU is in real-time single-step mode, the watchdog clock
(WDCLK) is suspended. The watchdog remains suspended even within realtime interrupts.
When the CPU is in real-time run-free mode, the watchdog operates as
normal.
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3.4.5
Watchdog Registers
The system control and status register (SCSR) contains the watchdog override bit and the watchdog
interrupt enable/disable bit. Figure 32 describes the bit functions of the SCSR register.
Figure 32. System Control and Status Register (SCSR)
15
8
Reserved
R-0
7
2
1
0
Reserved
3
WDINTS
WDENINT
WDOVERRIDE
R-0
R-1
R/W-0
R/W1C-1
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 37. System Control and Status Register (SCSR) Field Descriptions
Bit
Field
Value
Description
(1)
15-3
Reserved
Any writes to these bit(s) must always have a value of 0.
2
WDINTS
Watchdog interrupt status bit. WDINTS reflects the current state of the WDINT signal from the
watchdog block. WDINTS follows the state of WDINT by two SYSCLKOUT cycles.
If the watchdog interrupt is used to wake the device from IDLE or STANDBY low power mode, use
this bit to make sure WDINT is not active before attempting to go back into IDLE or STANDBY
mode.
1
0
Watchdog interrupt signal (WDINT) is active.
1
Watchdog interrupt signal (WDINT) is not active.
WDENINT
Watchdog interrupt enable.
0
The watchdog reset (WDRST) output signal is enabled and the watchdog interrupt (WDINT) output
signal is disabled. This is the default state on reset (XRS). When the watchdog interrupt occurs the
WDRST signal will stay low for 512 OSCCLK cycles.
If the WDENINT bit is cleared while WDINT is low, a reset will immediately occur. The WDINTS bit
can be read to determine the state of the WDINT signal.
1
The WDRST output signal is disabled and the WDINT output signal is enabled. When the watchdog
interrupt occurs, the WDINTsignal will stay low for 512 OSCCLK cycles.
If the watchdog interrupt is used to wake the device from IDLE or STANDBY low power mode, use
the WDINTS bit to make sure WDINT is not active before attempting to go back into IDLE or
STANDBY mode.
0
(1)
WDOVERRIDE
Watchdog override
0
Writing a 0 has no effect. If this bit is cleared, it remains in this state until a reset occurs. The
current state of this bit is readable by the user.
1
You can change the state of the watchdog disable (WDDIS) bit in the watchdog control (WDCR)
register. If the WDOVERRIDE bit is cleared by writing a 1, you cannot modify the WDDIS bit.
This register is EALLOW protected. See Section 5.2 for more information.
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Figure 33. Watchdog Counter Register (WDCNTR)
15
8
7
0
Reserved
WDCNTR
R-0
R-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 38. Watchdog Counter Register (WDCNTR) Field Descriptions
Bits
Field
Description
15-8
Reserved
Any writes to these bit(s) must always have a value of 0.
7-0
WDCNTR
These bits contain the current value of the WD counter. The 8-bit counter continually increments at the
watchdog clock (WDCLK), rate. If the counter overflows, then the watchdog initiates a reset. If the WDKEY
register is written with a valid combination, then the counter is reset to zero. The watchdog clock rate is
configured in the WDCR register.
Figure 34. Watchdog Reset Key Register (WDKEY)
15
8
7
0
Reserved
WDKEY
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 39. Watchdog Reset Key Register (WDKEY) Field Descriptions
Bits
Field
15-8
Reserved
7-0
WDKEY
Value
Description
(1)
Any writes to these bit(s) must always have a value of 0.
Refer to Table 36 for examples of different WDKEY write sequences.
0x55 + 0xAA
Writing 0x55 followed by 0xAA to WDKEY causes the WDCNTR bits to be cleared.
Other value
Writing any value other than 0x55 or 0xAA causes no action to be generated. If any value other than
0xAA is written after 0x55, then the sequence must restart with 0x55.
Reads from WDKEY return the value of the WDCR register.
(1)
This register is EALLOW protected. See Section 5.2 for more information.
Figure 35. Watchdog Control Register (WDCR)
15
8
Reserved
R-0
7
6
WDFLAG
WDDIS
5
WDCHK
3
2
WDPS
0
R/W1C-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 40. Watchdog Control Register (WDCR) Field Descriptions
Bits
15-8
Reserved
7
WDFLAG
6
(1)
60
Field
Value
Description
(1)
Any writes to these bit(s) must always have a value of 0.
Watchdog reset status flag bit
0
The reset was caused either by the XRS pin or because of power-up. The bit remains latched
until you write a 1 to clear the condition. Writes of 0 are ignored.
1
Indicates a watchdog reset (WDRST) generated the reset condition. .
WDDIS
Watchdog disable. On reset, the watchdog module is enabled.
0
Enables the watchdog module. WDDIS can be modified only if the WDOVERRIDE bit in the
SCSR register is set to 1. (default)
1
Disables the watchdog module.
This register is EALLOW protected. See Section 5.2 for more information.
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Table 40. Watchdog Control Register (WDCR) Field Descriptions (continued)
Bits
5-3
2-0
Field
Value
WDCHK
Description
(1)
Watchdog check.
0,0,0
You must ALWAYS write 1,0,1 to these bits whenever a write to this register is performed
unless the intent is to reset the device via software.
other
Writing any other value causes an immediate device reset or watchdog interrupt to be taken.
Note that this happens even when watchdog module is disabled. Do not write to WDCHK bits
when the watchdog module is disabled. These bits can be used to generate a software reset
of the device. These three bits always read back as zero (0, 0, 0).
WDPS
Watchdog pre-scale. These bits configure the watchdog counter clock (WDCLK) rate relative
to OSCCLK/512:
000
WDCLK = OSCCLK/512/1 (default)
001
WDCLK = OSCCLK/512/1
010
WDCLK = OSCCLK/512/2
011
WDCLK = OSCCLK/512/4
100
WDCLK = OSCCLK/512/8
101
WDCLK = OSCCLK/512/16
110
WDCLK = OSCCLK/512/32
111
WDCLK = OSCCLK/512/64
When the XRS line is low, the WDFLAG bit is forced low. The WDFLAG bit is only set if a rising edge on
WDRST signal is detected (after synch and an 8192 SYSCLKOUT cycle delay) and the XRS signal is
high. If the XRS signal is low when WDRST goes high, then the WDFLAG bit remains at 0. In a typical
application, the WDRST signal connects to the XRS input. Hence to distinguish between a watchdog reset
and an external device reset, an external reset must be longer in duration then the watchdog pulse.
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32-Bit CPU Timers 0/1/2
This section describes the three 32-bit CPU-timers (TIMER0/1/2) shown in (Figure 36).
The CPU Timer-0 and CPU-Timer 1 can be used in user applications. Timer 2 is reserved for DSP/BIOS.
If the application is not using DSP/BIOS, then Timer 2 can be used in the application. The CPU-timer
interrupt signals (TINT0, TINT1, TINT2) are connected as shown in Figure 37.
Figure 36. CPU-Timers
Reset
Timer reload
16-bit timer divide-down
TDDRH:TDDR
32-bit timer period
PRDH:PRD
16-bit prescale counter
PSCH:PSC
SYSCLKOUT
TCR.4
(Timer start status)
32-bit counter
TIMH:TIM
Borrow
Borrow
TINT
Figure 37. CPU-Timer Interrupts Signals and Output Signal
INT1
to
INT12
PIE
TINT0
CPU-TIMER 0
28x
CPU
TINT1
CPU-TIMER 1
INT13
XINT13
TINT2
INT14
62
CPU-TIMER 2
A
The timer registers are connected to the Memory Bus of the 28x processor.
B
The timing of the timers is synchronized to SYSCLKOUT of the processor clock.
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The general operation of the CPU-timer is as follows: The 32-bit counter register TIMH:TIM is loaded with
the value in the period register PRDH:PRD. The counter decrements once every (TPR[TDDRH:TDDR]+1)
SYSCLKOUT cycles, where TDDRH:TDDR is the timer divider. When the counter reaches 0, a timer
interrupt output signal generates an interrupt pulse. The registers listed in Table 41 are used to configure
the timers.
Table 41. CPU-Timers 0, 1, 2 Configuration and Control Registers
Name
Address
Size (x16)
Description
Bit Description
TIMER0TIM
0x0C00
1
CPU-Timer 0, Counter Register
Figure 38
TIMER0TIMH
0x0C01
1
CPU-Timer 0, Counter Register High
Figure 39
TIMER0PRD
0x0C02
1
CPU-Timer 0, Period Register
Figure 40
TIMER0PRDH
0x0C03
1
CPU-Timer 0, Period Register High
Figure 41
TIMER0TCR
0x0C04
1
CPU-Timer 0, Control Register
Figure 42
TIMER0TPR
0x0C06
1
CPU-Timer 0, Prescale Register
Figure 43
TIMER0TPRH
0x0C07
1
CPU-Timer 0, Prescale Register High
Figure 44
TIMER1TIM
0x0C08
1
CPU-Timer 1, Counter Register
Figure 38
TIMER1TIMH
0x0C09
1
CPU-Timer 1, Counter Register High
Figure 39
TIMER1PRD
0x0C0A
1
CPU-Timer 1, Period Register
Figure 40
TIMER1PRDH
0x0C0B
1
CPU-Timer 1, Period Register High
Figure 41
TIMER1TCR
0x0C0C
1
CPU-Timer 1, Control Register
Figure 42
TIMER1TPR
0x0C0E
1
CPU-Timer 1, Prescale Register
Figure 43
TIMER1TPRH
0x0C0F
1
CPU-Timer 1, Prescale Register High
Figure 44
TIMER2TIM
0x0C10
1
CPU-Timer 2, Counter Register
Figure 38
TIMER2TIMH
0x0C11
1
CPU-Timer 2, Counter Register High
Figure 39
TIMER2PRD
0x0C12
1
CPU-Timer 2, Period Register
Figure 40
TIMER2PRDH
0x0C13
1
CPU-Timer 2, Period Register High
Figure 41
TIMER2TCR
0x0C14
1
CPU-Timer 2, Control Register
Figure 42
TIMER2TPR
0x0C16
1
CPU-Timer 2, Prescale Register
Figure 43
TIMER2TPRH
0x0C17
1
CPU-Timer 2, Prescale Register High
Figure 44
Figure 38. TIMERxTIM Register (x = 0, 1, 2)
15
0
TIM
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 42. TIMERxTIM Register Field Descriptions
Bits
15-0
Field
TIM
Description
CPU-Timer Counter Registers (TIMH:TIM): The TIM register holds the low 16 bits of the current 32-bit count
of the timer. The TIMH register holds the high 16 bits of the current 32-bit count of the timer. The TIMH:TIM
decrements by one every (TDDRH:TDDR+1) clock cycles, where TDDRH:TDDR is the timer prescale dividedown value. When the TIMH:TIM decrements to zero, the TIMH:TIM register is reloaded with the period
value contained in the PRDH:PRD registers. The timer interrupt (TINT) signal is generated.
Figure 39. TIMERxTIMH Register (x = 0, 1, 2)
15
0
TIMH
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
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Table 43. TIMERxTIMH Register Field Descriptions
Bits
Field
Description
15-0
TIMH
See description for TIMERxTIM.
Figure 40. TIMERxPRD Register (x = 0, 1, 2)
15
0
PRD
R/W-1
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 44. TIMERxPRD Register Field Descriptions
Bits
Field
15-0
Description
PRD
CPU-Timer Period Registers (PRDH:PRD): The PRD register holds the low 16 bits of the 32-bit period. The
PRDH register holds the high 16 bits of the 32-bit period. When the TIMH:TIM decrements to zero, the
TIMH:TIM register is reloaded with the period value contained in the PRDH:PRD registers, at the start of
the next timer input clock cycle (the output of the prescaler). The PRDH:PRD contents are also loaded into
the TIMH:TIM when you set the timer reload bit (TRB) in the Timer Control Register (TCR).
Figure 41. TIMERxPRDH Register (x = 0, 1, 2)
15
0
PRDH
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 45. TIMERxPRDH Register Field Descriptions
Bits
Field
15-0
Description
PRDH
See description for TIMERxPRD
Figure 42. TIMERxTCR Register (x = 0, 1, 2)
15
14
13
12
11
10
9
8
TIF
TIE
Reserved
FREE
SOFT
Reserved
R/W-0
R/W-0
R-0
R/W-0
R/W-0
R-0
7
5
4
Reserved
6
TRB
TSS
3
Reserved
0
R-0
R/W-0
R/W-0
R-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 46. TIMERxTCR Register Field Descriptions
Bits
15
Field
Value
TIF
Description
CPU-Timer Interrupt Flag.
0
The CPU-Timer has not decremented to zero.
Writes of 0 are ignored.
1
This flag gets set when the CPU-timer decrements to zero.
Writing a 1 to this bit clears the flag.
14
TIE
13-12 Reserved
64
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CPU-Timer Interrupt Enable.
0
The CPU-Timer interrupt is disabled.
1
The CPU-Timer interrupt is enabled. If the timer decrements to zero, and TIE is set, the
timer asserts its interrupt request.
Any writes to these bit(s) must always have a value of 0.
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Table 46. TIMERxTCR Register Field Descriptions (continued)
Bits
Field
Value
Description
11-10 FREE
SOFT
CPU-Timer Emulation Modes: These bits are special emulation bits that determine the
state of the timer when a breakpoint is encountered in the high-level language
debugger. If the FREE bit is set to 1, then, upon a software breakpoint, the timer
continues to run (that is, free runs). In this case, SOFT is a don't care. But if FREE is 0,
then SOFT takes effect. In this case, if SOFT = 0, the timer halts the next time the
TIMH:TIM decrements. If the SOFT bit is 1, then the timer halts when the TIMH:TIM
has decremented to zero.
FREE
SOFT
0
0
CPU-Timer Emulation Mode
Stop after the next decrement of the TIMH:TIM (hard stop)
0
1
Stop after the TIMH:TIM decrements to 0 (soft stop)
1
0
Free run
1
1
Free run
In the SOFT STOP mode, the timer generates an interrupt before shutting down (since
reaching 0 is the interrupt causing condition).
9-6
5
4
Reserved
Any writes to these bit(s) must always have a value of 0.
TRB
CPU-Timer Reload bit.
0
The TRB bit is always read as zero. Writes of 0 are ignored.
1
When you write a 1 to TRB, the TIMH:TIM is loaded with the value in the PRDH:PRD,
and the prescaler counter (PSCH:PSC) is loaded with the value in the timer dividedown register (TDDRH:TDDR).
TSS
CPU-Timer stop status bit. TSS is a 1-bit flag that stops or starts the CPU-timer.
0
Reads of 0 indicate the CPU-timer is running.
To start or restart the CPU-timer, set TSS to 0. At reset, TSS is cleared to 0 and the
CPU-timer immediately starts.
1
Reads of 1 indicate that the CPU-timer is stopped.
To stop the CPU-timer, set TSS to 1.
3-0
Reserved
Any writes to these bit(s) must always have a value of 0.
Figure 43. TIMERxTPR Register (x = 0, 1, 2)
15
8
7
0
PSC
TDDR
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 47. TIMERxTPR Register Field Descriptions
Bits
Field
Description
15-8
PSC
CPU-Timer Prescale Counter. These bits hold the current prescale count for the timer. For every timer clock
source cycle that the PSCH:PSC value is greater than 0, the PSCH:PSC decrements by one. One timer clock
(output of the timer prescaler) cycle after the PSCH:PSC reaches 0, the PSCH:PSC is loaded with the contents
of the TDDRH:TDDR, and the timer counter register (TIMH:TIM) decrements by one. The PSCH:PSC is also
reloaded whenever the timer reload bit (TRB) is set by software. The PSCH:PSC can be checked by reading
the register, but it cannot be set directly. It must get its value from the timer divide-down register
(TDDRH:TDDR). At reset, the PSCH:PSC is set to 0.
7-0
TDDR
CPU-Timer Divide-Down. Every (TDDRH:TDDR + 1) timer clock source cycles, the timer counter register
(TIMH:TIM) decrements by one. At reset, the TDDRH:TDDR bits are cleared to 0. To increase the overall timer
count by an integer factor, write this factor minus one to the TDDRH:TDDR bits. When the prescaler counter
(PSCH:PSC) value is 0, one timer clock source cycle later, the contents of the TDDRH:TDDR reload the
PSCH:PSC, and the TIMH:TIM decrements by one. TDDRH:TDDR also reloads the PSCH:PSC whenever the
timer reload bit (TRB) is set by software.
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Figure 44. TIMERxTPRH Register (x = 0, 1, 2)
15
8
7
0
PSCH
TDDRH
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 48. TIMERxTPRH Register Field Descriptions
66
Bits
Field
Description
15-8
PSCH
See description of TIMERxTPR.
7-0
TDDRH
See description of TIMERxTPR.
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4
General-Purpose Input/Output (GPIO)
The GPIO multiplexing (MUX) registers are used to select the operation of shared pins. The pins are
named by their general purpose I/O name (that is, GPIO0 - GPIO38 ). These pins can be individually
selected to operate as digital I/O, referred to as GPIO, or connected to one of up to three peripheral I/O
signals (via the GPxMUXn registers). If selected for digital I/O mode, registers are provided to configure
the pin direction (via the GPxDIR registers). You can also qualify the input signals to remove unwanted
noise (via the GPxQSELn, GPACTRL, and GPBCTRL registers).
4.1
GPIO Module Overview
Up to three independent peripheral signals are multiplexed on a single GPIO-enabled pin in addition to
individual pin bit-I/O capability. There are three I/O ports. Port A consists of GPIO0-GPIO31, port B
consists of GPIO32-GPIO38 . The analog port consists of AIO0-AIO15. Figure 45 shows the basic modes
of operation for the GPIO module. Note that GPIO functionality is provided on JTAG pins as well.
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Figure 45. GPIO0 to GPIO31 Multiplexing Diagram
GPIOLPMSEL
GPIO XINT1SEL
LPMCR0
GPIO XINT2SEL
GPIO XINT3SEL
Low power
modes block
External
interrupt
MUX
GPIOx.async
GPAPUD
0 = enable PU
1 = disable PU
(disabled after reset)
XRS
PU
(async disable
when low)
GPADAT (read)
SYSCLKOUT
(default
on reset)
Sync
3 samples
Qual
GPIO0
to
GPIO31
Pins
PIE
6 samples
async
00
00
N/C (default on reset)
01
01
Peripheral 1 input
10
10
Peripheral 2 input
11
11
Peripheral 3 input
GPASET,
GPACTRL
GPACLEAR,
GPAQSEL 1/2
GPATOGGLE
2
High
impedance
output
control
00
GPAMUX 1/2
(default on reset)
GPIOx_OUT
GPADAT
(latch)
01
Peripheral 1 output
10
Peripheral 2 output
11
Peripheral 3 output
2
00
(default on reset)
GPIOx_DIR
GPADIR
01
(latch)
Peripheral 1 output enable
10
Peripheral 2 output enable
11
Peripheral 3 output enable
0 = input, 1 = output
XRS
A
68
GPxDAT latch/read are accessed at the same memory location.
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Figure 46. GPIO32, GPIO33 Multiplexing Diagram
GPBPUD
SYSCLKOUT
0 = enable PU
1 = disable PU
(disabled after reset)
XRS
PU
(async disable
when low)
GPBDAT (read)
(default on reset)
Sync
3 samples
Qual
6 samples
async
GPIO32,
GPIO33
Pins
00
00
N/C
01
01
Perpheral 1 input
10
10
Peripheral 2 input
11
11
Peripheral 3 input
GPBSET
GPBCTRL
GPBCLEAR
GPBTOGGLE
High
Impedance
Output
Control
GPBSEL1
2
GPIO32/33_OUT
(default on reset)
00
GPBMUX1
01
Perpheral 1 output
10
Peripheral 2 output
11
Peripheral 3 output
(default on reset)
GPIO32/33-DIR
2
00
0x
0 = Input , 1 = Output
Default at Reset
GPBDAT
(latch)
GPBDIR
(latch)
SDAA/SCLA (I2C output enable)
01
SDAA/SCLA (I2C data out)
10
1x
Peripheral 2 output enable
11
Peripheral 3 output enable
XRS
4.1.1
A
The GPIOINENCLK bit in the PCLKCR3 register does not affect the above GPIOs (I2C pins) since the pins are bidirectional.
B
The input qualification circuit is not reset when modes are changed (such as changing from output to input mode).
Any state will get flushed by the circuit eventually.
JTAG Port
On this device, the JTAG port is reduced to five pins (TRST, TCK, TDI, TMS, TDO). TCK, TDI, TMS and
TDO pins are also GPIO pins. The TRST signal selects either JTAG or GPIO operating mode for the pins
in Figure 47.
NOTE: The JTAG pins may also be used as GPIO pins. Care should be taken in the board design to
ensure that the circuitry connected to these pins do not affect the emulation capabilities of
the JTAG pin function. Any circuitry connected to these pins should not prevent the emulator
from driving (or being driven by) the JTAG pins for successful debug.
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Figure 47. JTAG Port/GPIO Multiplexing
TRST = 0: JTAG Disabled (GPIO Mode)
TRST = 1: JTAG Mode
TRST
TRST
XCLKIN
GPIO38_in
TCK
TCK/GPIO38
GPIO38_out
C28x
Core
GPIO37_in
TDO/GPIO37
1
0
TDO
GPIO37_out
GPIO36_in
1
TMS/GPIO36
GPIO36_out
1
TMS
0
GPIO35_in
1
TDI/GPIO35
GPIO35_out
70
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1
TDI
0
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Figure 48. Analog/GPIO Multiplexing
To COMPy A or B input
To ADC Channel X
Logic implemented in GPIO MUX block
AIOx Pin
SYSCLKOUT
AIOxIN
1
AIOxINE
AIODAT Reg
(Read)
SYNC
0
AIODAT Reg
(Latch)
AIOMUX1 Reg
AIOxDIR
(1 = Input,
0 = Output)
AIOSET,
AIOCLEAR,
AIOTOGGLE
Regs
AIODIR Reg
(Latch)
1
(0 = Input, 1 = Output)
0
A
The ADC/Comparator path is always enabled, irrespective of the AIOMUX1 value.
B
The AIO section is blocked off when the corresponding AIOMUX1 bit is 1.
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Configuration Overview
The pin function assignments, input qualification, and the external interrupt sources are all controlled by
the GPIO configuration control registers. In addition, you can assign pins to wake the device from the
HALT and STANDBY low power modes and enable/disable internal pullup resistors. Table 49 and
Table 50 list the registers that are used to configure the GPIO pins to match the system requirements.
Table 49. GPIO Control Registers
Name
(1)
Register Description
Bit Description
GPACTRL
0x6F80
2
GPIO A Control Register (GPIO0-GPIO31)
Figure 55
GPAQSEL1
0x6F82
2
GPIO A Qualifier Select 1 Register (GPIO0-GPIO15)
Figure 57
GPAQSEL2
0x6F84
2
GPIO A Qualifier Select 2 Register (GPIO16-GPIO31)
Figure 58
GPAMUX1
0x6F86
2
GPIO A MUX 1 Register (GPIO0-GPIO15)
Figure 51
GPAMUX2
0x6F88
2
GPIO A MUX 2 Register (GPIO16-GPIO31)
Figure 52
GPADIR
0x6F8A
2
GPIO A Direction Register (GPIO0-GPIO31)
Figure 60
GPAPUD
0x6F8C
2
GPIO A Pull Up Disable Register (GPIO0-GPIO31)
Figure 63
GPBCTRL
0x6F90
2
GPIO B Control Register (GPIO32-GPIO38 )
Figure 56
GPBQSEL1
0x6F92
2
GPIO B Qualifier Select 1 Register (GPIO32-GPIO38 )
Figure 59
GPBMUX1
0x6F96
2
GPIO B MUX 1 Register (GPIO32-GPIO38 )
Figure 53
GPBDIR
0x6F9A
2
GPIO B Direction Register (GPIO32-GPIO38 )
Figure 61
GPBPUD
0x6F9C
2
GPIO B Pull Up Disable Register (GPIO32-GPIO38 )
Figure 64
AIOMUX1
0x6FB6
2
Analog, I/O MUX 1 register (AIO0 - AIO15)
Figure 54
AIODIR
0x6FBA
2
Analog, I/O Direction Register (AIO0 - AIO15)
Figure 62
(1)
Address
Size (x16)
The registers in this table are EALLOW protected. See Section 5.2 for more information.
Table 50. GPIO Interrupt and Low Power Mode Select Registers
Address
Size
(x16)
GPIOXINT1SEL
0x6FE0
GPIOXINT2SEL
0x6FE1
GPIOXINT3SEL
GPIOLPMSEL
Name
(1)
72
(1)
Register Description
Bit Description
1
XINT1 Source Select Register (GPIO0-GPIO31)
Figure 71
1
XINT2 Source Select Register (GPIO0-GPIO31)
Figure 71
0x6FE2
1
XINT3 Source Select Register (GPIO0 - GPIO31)
Figure 71
0x6FE8
1
LPM wakeup Source Select Register (GPIO0-GPIO31)
Figure 72
The registers in this table are EALLOW protected. See Section 5.2 for more information.
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To plan configuration of the GPIO module, consider the following steps:
Step 1. Plan the device pin-out:
Through a pin multiplexing scheme, a lot of flexibility is provided for assigning functionality to the
GPIO-capable pins. Before getting started, look at the peripheral options available for each pin, and
plan pin-out for your specific system. Will the pin be used as a general purpose input or output (GPIO)
or as one of up to three available peripheral functions? Knowing this information will help determine
how to further configure the pin.
Step 2. Enable or disable internal pull-up resistors:
To enable or disable the internal pullup resistors, write to the respective bits in the GPIO pullup disable
(GPAPUD and GPBPUD) registers. For pins that can function as ePWM output pins, the internal pullup
resistors are disabled by default. All other GPIO-capable pins have the pullup enabled by default. The
AIOx pins do not have internal pull-up resistors.
Step 3. Select input qualification:
If the pin will be used as an input, specify the required input qualification, if any. The input qualification
is specified in the GPACTRL, GPBCTRL, GPAQSEL1, GPAQSEL2, GPBQSEL1, and GPBQSEL2
registers. By default, all of the input signals are synchronized to SYSCLKOUT only.
Step 4. Select the pin function:
Configure the GPxMUXn or AIOMUXn registers such that the pin is a GPIO or one of three available
peripheral functions. By default, all GPIO-capable pins are configured at reset as general purpose input
pins.
Step 5. For digital general purpose I/O, select the direction of the pin:
If the pin is configured as an GPIO, specify the direction of the pin as either input or output in the
GPADIR, GPBDIR, or AIODIR registers. By default, all GPIO pins are inputs. To change the pin from
input to output, first load the output latch with the value to be driven by writing the appropriate value to
the GPxCLEAR, GPxSET, or GPxTOGGLE (or AIOCLEAR, AIOSET, or AIOTOGGLE) registers. Once
the output latch is loaded, change the pin direction from input to output via the GPxDIR registers. The
output latch for all pins is cleared at reset.
Step 6. Select low power mode wake-up sources:
Specify which pins, if any, will be able to wake the device from HALT and STANDBY low power
modes. The pins are specified in the GPIOLPMSEL register.
Step 7. Select external interrupt sources:
Specify the source for the XINT1 - XINT3 interrupts. For each interrupt you can specify one of the port
A signals as the source. This is done by specifying the source in the GPIOXINTnSEL register. The
polarity of the interrupts can be configured in the XINTnCR register as described in Section 6.6.
NOTE: There is a 2-SYSCLKOUT cycle delay from when a write to configuration registers such as
GPxMUXn and GPxQSELn occurs to when the action is valid.
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Digital General Purpose I/O Control
For pins that are configured as GPIO you can change the values on the pins by using the registers in
Table 51.
Table 51. GPIO Data Registers
Name
Address
Size (x16)
Register Description
Bit Description
GPADAT
0x6FC0
2
GPIO A Data Register (GPIO0-GPIO31-)
Figure 65
GPASET
0x6FC2
2
GPIO A Set Register (GPIO0-GPIO31)
Figure 68
GPACLEAR
0x6FC4
2
GPIO A Clear Register (GPIO0-GPIO31)
Figure 68
GPATOGGLE
0x6FC6
2
GPIO A Toggle Register (GPIO0-GPIO31)
Figure 68
GPBDAT
0x6FC8
2
GPIO B Data Register (GPIO32-GPIO44)
Figure 66
GPBSET
0x6FCA
2
GPIO B Set Register (GPIO32-GPIO44)
Figure 69
GPBCLEAR
0x6FCC
2
GPIO B Clear Register (GPIO32-GPIO44)
Figure 69
GPBTOGGLE
0x6FCE
2
GPIO B Toggle Register (GPIO32-GPIO44)
Figure 69
AIODAT
0x6FD8
2
Analog I/O Data Register (AIO0 - AIO15)
Figure 67
AIOSET
0x6FDA
2
Analog I/O Data Set Register (AIO0 - AIO15)
Figure 70
AIOCLEAR
0x6FDC
2
Analog I/O Clear Register (AIO0 - AIO15)
Figure 70
AIOTOGGLE
0x6FDE
2
Analog I/O Toggle Register (AIO0 - AIO15)
Figure 70
•
GPxDAT/AIODAT Registers
Each I/O port has one data register. Each bit in the data register corresponds to one GPIO pin. No
matter how the pin is configured (GPIO or peripheral function), the corresponding bit in the data
register reflects the current state of the pin after qualification (This does not apply to AIOx pins).
Writing to the GPxDAT/AIODAT register clears or sets the corresponding output latch and if the pin is
enabled as a general purpose output (GPIO output) the pin will also be driven either low or high. If the
pin is not configured as a GPIO output then the value will be latched, but the pin will not be driven.
Only if the pin is later configured as a GPIO output, will the latched value be driven onto the pin.
When using the GPxDAT register to change the level of an output pin, you should be cautious not to
accidentally change the level of another pin. For example, if you mean to change the output latch level
of GPIOA1 by writing to the GPADAT register bit 0 using a read-modify-write instruction, a problem can
occur if another I/O port A signal changes level between the read and the write stage of the instruction.
Following is an analysis of why this happens:
The GPxDAT registers reflect the state of the pin, not the latch. This means the register reflects the
actual pin value. However, there is a lag between when the register is written to when the new pin
value is reflected back in the register. This may pose a problem when this register is used in
subsequent program statements to alter the state of GPIO pins. An example is shown below where two
program statements attempt to drive two different GPIO pins that are currently low to a high state.
If Read-Modify-Write operations are used on the GPxDAT registers, because of the delay between the
output and the input of the first instruction (I1), the second instruction (I2) will read the old value and
write it back.
GpioDataRegs.GPADAT.bit.GPIO1 = 1 ; I1 performs read-modifywrite of GPADAT GpioDataRegs.GPADAT.bit.GPIO2 = 1 ; I2 also a read-modifywrite of GPADAT. ; It gets the old value of GPIO1 due to the delay
The second instruction will wait for the first to finish its write due to the write-followed-by-read
protection on this peripheral frame. There will be some lag, however, between the write of (I1) and the
GPxDAT bit reflecting the new value (1) on the pin. During this lag, the second instruction will read the
old value of GPIO1 (0) and write it back along with the new value of GPIO2 (1). Therefore, GPIO1 pin
stays low.
One solution is to put some NOP’s between instructions. A better solution is to use the
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•
•
•
4.4
GPxSET/GPxCLEAR/GPxTOGGLE registers instead of the GPxDAT registers. These registers always
read back a 0 and writes of 0 have no effect. Only bits that need to be changed can be specified
without disturbing any other bits that are currently in the process of changing.
GPxSET/AIOSET Registers
The set registers are used to drive specified GPIO pins high without disturbing other pins. Each I/O
port has one set register and each bit corresponds to one GPIO pin. The set registers always read
back 0. If the corresponding pin is configured as an output, then writing a 1 to that bit in the set register
will set the output latch high and the corresponding pin will be driven high. If the pin is not configured
as a GPIO output, then the value will be latched but the pin will not be driven. Only if the pin is later
configured as a GPIO output will the latched value will be driven onto the pin. Writing a 0 to any bit in
the set registers has no effect.
GPxCLEAR/AIOCLEAR Registers
The clear registers are used to drive specified GPIO pins low without disturbing other pins. Each I/O
port has one clear register. The clear registers always read back 0. If the corresponding pin is
configured as a general purpose output, then writing a 1 to the corresponding bit in the clear register
will clear the output latch and the pin will be driven low. If the pin is not configured as a GPIO output,
then the value will be latched but the pin will not be driven. Only if the pin is later configured as a GPIO
output will the latched value will be driven onto the pin. Writing a 0 to any bit in the clear registers has
no effect.
GPxTOGGLE/AIOTOGGLE Registers
The toggle registers are used to drive specified GPIO pins to the opposite level without disturbing other
pins. Each I/O port has one toggle register. The toggle registers always read back 0. If the
corresponding pin is configured as an output, then writing a 1 to that bit in the toggle register flips the
output latch and pulls the corresponding pin in the opposite direction. That is, if the output pin is driven
low, then writing a 1 to the corresponding bit in the toggle register will pull the pin high. Likewise, if the
output pin is high, then writing a 1 to the corresponding bit in the toggle register will pull the pin low. If
the pin is not configured as a GPIO output, then the value will be latched but the pin will not be driven.
Only if the pin is later configured as a GPIO output will the latched value will be driven onto the pin.
Writing a 0 to any bit in the toggle registers has no effect.
Input Qualification
The input qualification scheme has been designed to be very flexible. You can select the type of input
qualification for each GPIO pin by configuring the GPAQSEL1, GPAQSEL2, GPBQSEL1 and GPBQSEL2
registers. In the case of a GPIO input pin, the qualification can be specified as only synchronize to
SYSCLKOUT or qualification by a sampling window. For pins that are configured as peripheral inputs, the
input can also be asynchronous in addition to synchronized to SYSCLKOUT or qualified by a sampling
window. The remainder of this section describes the options available.
4.4.1
No Synchronization (asynchronous input)
This mode is used for peripherals where input synchronization is not required or the peripheral itself
performs the synchronization. Examples include communication ports SCI, SPI, and I2C. In addition, it may
be desirable to have the ePWM trip zone (TZn) signals function independent of the presence of
SYSCLKOUT.
The asynchronous option is not valid if the pin is used as a general purpose digital input pin (GPIO). If the
pin is configured as a GPIO input and the asynchronous option is selected then the qualification defaults
to synchronization to SYSCLKOUT as described in Section 4.4.2.
4.4.2
Synchronization to SYSCLKOUT Only
This is the default qualification mode of all the pins at reset. In this mode, the input signal is only
synchronized to the system clock (SYSCLKOUT). Because the incoming signal is asynchronous, it can
take up to a SYSCLKOUT period of delay in order for the input to the device to be changed. No further
qualification is performed on the signal.
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Qualification Using a Sampling Window
In this mode, the signal is first synchronized to the system clock (SYSCLKOUT) and then qualified by a
specified number of cycles before the input is allowed to change. Figure 49 and Figure 50 show how the
input qualification is performed to eliminate unwanted noise. Two parameters are specified by the user for
this type of qualification: 1) the sampling period, or how often the signal is sampled, and 2) the number of
samples to be taken.
Figure 49. Input Qualification Using a Sampling Window
Time between samples
GPxCTRL Reg
GPIOx
SYNC
Qualification
Input Signal
Qualified By 3
or 6 Samples
GPxQSEL1/2
SYSCLKOUT
Number of Samples
Time between samples (sampling period):
To qualify the signal, the input signal is sampled at a regular period. The sampling period is specified by
the user and determines the time duration between samples, or how often the signal will be sampled,
relative to the CPU clock (SYSCLKOUT).
The sampling period is specified by the qualification period (QUALPRDn) bits in the GPxCTRL register.
The sampling period is configurable in groups of 8 input signals. For example, GPIO0 to GPIO7 use
GPACTRL[QUALPRD0] setting and GPIO8 to GPIO15 use GPACTRL[QUALPRD1]. Table 52 and
Table 53 show the relationship between the sampling period or sampling frequency and the
GPxCTRL[QUALPRDn] setting.
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Table 52. Sampling Period
If GPxCTRL[QUALPRDn] = 0
If GPxCTRL[QUALPRDn] ≠ 0
Sampling Period
1 × TSYSCLKOUT
2 × GPxCTRL[QUALPRDn] × TSYSCLKOUT
Where TSYSCLKOUT is the period in time of SYSCLKOUT
Table 53. Sampling Frequency
If GPxCTRL[QUALPRDn] = 0
If GPxCTRL[QUALPRDn] ≠ 0
Sampling Frequency
fSYSCLKOUT
fSYSCLKOUT × 1 ÷ (2 × GPxCTRL[QUALPRDn])
Where fSYSCLKOUT is the frequency of SYSCLKOUT
From these equations, the minimum and maximum time between samples can be calculated for a given
SYSCLKOUT frequency:
Example: Maximum Sampling Frequency:
If GPxCTRL[QUALPRDn] = 0
then the sampling frequency is fSYSCLKOUT
If, for example, fSYSCLKOUT = 60 MHz
then the signal will be sampled at 60 MHz or one sample every 16.67 ns.
Example: Minimum Sampling Frequency:
If GPxCTRL[QUALPRDn] = 0xFF (that is, 255)
then the sampling frequency is fSYSCLKOUT × 1 ÷ (2 × GPxCTRL[QUALPRDn])
If, for example, fSYSCLKOUT = 60 MHz
then the signal will be sampled at 60 MHz × 1 ÷ (2 × 255) or one sample every 8.5 μs.
Number of samples:
The number of times the signal is sampled is either 3 samples or 6 samples as specified in the
qualification selection (GPAQSEL1, GPAQSEL2, GPBQSEL1, and GPBQSEL2) registers. When 3 or 6
consecutive cycles are the same, then the input change will be passed through to the DSP.
Total Sampling Window Width:
The sampling window is the time during which the input signal will be sampled as shown in Figure 50. By
using the equation for the sampling period along with the number of samples to be taken, the total width of
the window can be determined.
For the input qualifier to detect a change in the input, the level of the signal must be stable for the duration
of the sampling window width or longer.
The number of sampling periods within the window is always one less then the number of samples taken.
For a thee-sample window, the sampling window width is 2 sampling periods wide where the sampling
period is defined in Table 52. Likewise, for a six-sample window, the sampling window width is 5 sampling
periods wide. Table 54 and Table 55 show the calculations that can be used to determine the total
sampling window width based on GPxCTRL[QUALPRDn] and the number of samples taken.
Table 54. Case 1: Three-Sample Sampling Window Width
If GPxCTRL[QUALPRDn] = 0
If GPxCTRL[QUALPRDn] ≠ 0
2 × TSYSCLKOUT
2 × 2 × GPxCTRL[QUALPRDn] × TSYSCLKOUT
Where TSYSCLKOUT is the period in time of SYSCLKOUT
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Table 55. Case 2: Six-Sample Sampling Window Width
If GPxCTRL[QUALPRDn] = 0
If GPxCTRL[QUALPRDn] ≠ 0
Total Sampling Window Width
5 × TSYSCLKOUT
5 × 2 × GPxCTRL[QUALPRDn] × TSYSCLKOUT
Where TSYSCLKOUT is the period in time of SYSCLKOUT
NOTE: The external signal change is asynchronous with respect to both the sampling period and
SYSCLKOUT. Due to the asynchronous nature of the external signal, the input should be
held stable for a time greater than the sampling window width to make sure the logic detects
a change in the signal. The extra time required can be up to an additional sampling period +
TSYSCLKOUT.
The required duration for an input signal to be stable for the qualification logic to detect a
change is described in the device specific data manual.
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Example Qualification Window:
For the example shown in Figure 50, the input qualification has been configured as follows:
• GPxQSEL1/2 = 1,0. This indicates a six-sample qualification.
• GPxCTRL[QUALPRDn] = 1. The sampling period is tw(SP) = 2 × GPxCTRL[QUALPRDn] × TSYSCLKOUT .
This configuration results in the following:
• The width of the sampling window is: .
tw(IQSW) = 5 × tw(SP) = 5 × 2 × GPxCTRL[QUALPRDn] × TSYSCLKOUT or 5 × 2 × TSYSCLKOUT
• If, for example, TSYSCLKOUT = 16.67 ns, then the duration of the sampling window is:
tw(IQSW) = 5 × 2 × 16.67 ns =166.7 ns.
• To account for the asynchronous nature of the input relative to the sampling period and SYSCLKOUT,
up to an additional sampling period, tw(SP), + TSYSCLKOUT may be required to detect a change in the
input signal. For this example:
tw(SP) + TSYSCLKOUT = 333.4 ns + 166.67 ns = 500.1 ns
• In Figure 50, the glitch (A) is shorter then the qualification window and will be ignored by the input
qualifier.
Figure 50. Input Qualifier Clock Cycles
(A)
GPIO Signal
GPxQSELn = 1,0 (6 samples)
1
1
0
0
0
0
0
0
0
1
tw(SP)
0
0
0
1
1
1
1
1
1
1
1
1
Sampling Period determined
by GPxCTRL[QUALPRD](B)
tw(IQSW)
(SYSCLKOUT cycle * 2 * QUALPRD) * 5(C))
Sampling Window
SYSCLKOUT
QUALPRD = 1
(SYSCLKOUT/2)
(D)
Output From
Qualifier
A. This glitch will be ignored by the input qualifier. The QUALPRD bit field specifies the qualification sampling period. It can vary from 00 to
0xFF. If QUALPRD = 00, then the sampling period is 1 SYSCLKOUT cycle. For any other value “n”, the qualification sampling period in 2n
SYSCLKOUT cycles (i.e., at every 2n SYSCLKOUT cycles, the GPIO pin will be sampled).
B. The qualification period selected via the GPxCTRL register applies to groups of 8 GPIO pins.
C. The qualification block can take either three or six samples. The GPxQSELn Register selects which sample mode is used.
D. In the example shown, for the qualifier to detect the change, the input should be stable for 10 SYSCLKOUT cycles or greater. In other words,
the inputs should be stable for (5 x QUALPRD x 2) SYSCLKOUT cycles. That would ensure 5 sampling periods for detection to occur. Since
external signals are driven asynchronously, an 13-SYSCLKOUT-wide pulse ensures reliable recognition.
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GPIO and Peripheral Multiplexing (MUX)
Up to three different peripheral functions are multiplexed along with a general input/output (GPIO) function
per pin. This allows you to pick and choose a peripheral mix that will work best for the particular
application.
Table 57 and Table 58 and show an overview of the possible multiplexing combinations sorted by GPIO
pin. The second column indicates the I/O name of the pin on the device. Since the I/O name is unique, it
is the best way to identify a particular pin. Therefore, the register descriptions in this section only refer to
the GPIO name of a particular pin. The MUX register and particular bits that control the selection for each
pin are indicated in the first column.
For example, the multiplexing for the GPIO6 pin is controlled by writing to GPAMUX[13:12]. By writing to
these bits, the pin is configured as either GPIO6, or one of up to three peripheral functions. The GPIO6
pin can be configured as follows:
GPAMUX1[13:12] Bit Setting
Pin Functionality Selected
If GPAMUX1[13:12] = 0,0
Pin configured as GPIO6
If GPAMUX1[13:12] = 0,1
Pin configured as EPWM4A (O)
If GPAMUX1[13:12] = 1,0
Pin configured as EPWMSYNCI (I)
If GPAMUX1[13:12] = 1,1
Pin configured as EPWMSYNCO (O)
The 2802x and 2803x devices have different multiplexing schemes. If a peripheral is not available on a
particular device, that MUX selection is reserved on that device and should not be used.
NOTE: If you should select a reserved GPIO MUX configuration that is not mapped to a peripheral,
the state of the pin will be undefined and the pin may be driven. Reserved configurations are
for future expansion and should not be selected. In the device MUX tablesTable 57 and
Table 58 and these options are indicated as Reserved .
Some peripherals can be assigned to more than one pin via the MUX registers. For example, in the 2803x
device, the SPISIMOB can be assigned to either the GPIO12 or GPIO24 pin, depending on individual
system requirements as shown below:
Pin Assigned to SPISIMOB
MUX Configuration
Choice 1 - GPIO12
GPAMUX[25:24] = 1,1
or Choice 2 - GPIO24
GPAMUX2[17:16] = 1,1
If no pin is configured as an input to a peripheral, or if more than one pin is configured as an input for the
same peripheral, then the input to the peripheral will either default to a 0 or a 1 as shown in Table 56. For
example, if SPISIMOB were assigned to both GPIO12 and GPIO24, the input to the SPI peripheral would
default to a high state as shown in Table 56 and the input would not be connected to GPIO12 or GPIO24.
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Table 56. Default State of Peripheral Input
Peripheral Input
Description
Default Input
TZ1-TZ3
Trip zone 1-3
1
EPWMSYNCI
ePWM Synch Input
0
ECAP1
eCAP1 input
1
SPICLKA
SPI-A clock
1
SPISTEA
SPI-A transmit enable
0
SPISIMOA
SPI-A Slave-in, master-out
1
SPISOMIA
SPI-A Slave-out, master-in
1
SCIRXDA - SCIRXDB
SCI-A - SCI-B receive
1
SDAA
I2C data
1
SCLA1
I2C clock
1
(1)
(1)
This value will be assigned to the peripheral input if more then one pin has been assigned to the peripheral function in the
GPxMUX1/2 registers or if no pin has been assigned.
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Table 57. 2802x GPIOA MUX
(1)
82
Default at Reset
Primary I/O Function
Peripheral Selection 1
Peripheral Selection 2
Peripheral Selection 3
GPAMUX1 Register
Bits
(GPAMUX1 bits = 00)
(GPAMUX1 bits = 01)
(GPAMUX1 bits = 10)
(GPAMUX1 bits = 11)
1-0
GPIO0
EPWM1A (O)
Reserved (1)
Reserved (1)
3-2
GPIO1
EPWM1B (O)
Reserved
COMP1OUT (O)
5-4
GPIO2
EPWM2A (O)
Reserved
Reserved (1)
7-6
GPIO3
EPWM2B (O)
Reserved
COMP2OUT (O)
9-8
GPIO4
EPWM3A (O)
Reserved
Reserved (1)
11-10
GPIO5
EPWM3B (O)
Reserved
ECAP1 (I/O)
13-12
GPIO6
EPWM4A (O)
EPWMSYNCI (I)
EPWMSYNCO (O)
15-14
GPIO7
EPWM4B (O)
SCIRXDA (I)
Reserved
17-16
Reserved
Reserved
Reserved
Reserved
19-18
Reserved
Reserved
Reserved
Reserved
21-20
Reserved
Reserved
Reserved
Reserved
23-22
Reserved
Reserved
Reserved
Reserved
25-24
GPIO12
TZ1 (I)
SCITXDA (O)
Reserved
27-26
Reserved
Reserved
Reserved
Reserved
29-28
Reserved
Reserved
Reserved
Reserved
31-30
Reserved
Reserved
Reserved
Reserved
GPAMUX2 Register
Bits
(GPAMUX2 bits = 00)
(GPAMUX2 bits = 01)
(GPAMUX2 bits = 10)
(GPAMUX2 bits = 11)
1-0
GPIO16
SPISIMOA (I/O)
Reserved
TZ2 (I)
3-2
GPIO17
SPISOMIA (I/O)
Reserved
TZ3 (I)
5-4
GPIO18
SPICLKA (I/O)
SCITXDA (O)
XCLKOUT (O)
7-6
GPIO19/XCLKIN
SPISTEA (I/O)
SCIRXDA (I)
ECAP1 (I/O)
9-8
Reserved
Reserved
Reserved
Reserved
11-10
Reserved
Reserved
Reserved
Reserved
13-12
Reserved
Reserved
Reserved
Reserved
15-14
Reserved
Reserved
Reserved
Reserved
17-16
Reserved
Reserved
Reserved
Reserved
19-18
Reserved
Reserved
Reserved
Reserved
21-20
Reserved
Reserved
Reserved
Reserved
23-22
Reserved
Reserved
Reserved
Reserved
25-24
GPIO28
SCIRXDA (I)
SDAA (I/OC)
TZ2 (O)
27-26
GPIO29
SCITXDA (O)
SCLA (I/OC)
TZ3 (O)
29-28
Reserved
Reserved
Reserved
Reserved
31-30
Reserved
Reserved
Reserved
Reserved
The word Reserved means that there is no peripheral assigned to this GPxMUX1/2 register setting. Should it be selected, the
state of the pin will be undefined and the pin may be driven. This selection is a reserved configuration for future expansion.
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Table 58. 2802x GPIOB MUX
Default at Reset
Primary I/O Function
Peripheral Selection 1
Peripheral Selection 2
Peripheral Selection 3
GPBMUX1 Register
Bits
(GPBMUX1 bits = 00)
(GPBMUX1 bits = 01)
(GPBMUX1 bits = 10)
(GPBMUX1 bits = 11)
1,0
GPIO32
SDAA (I/OC)
EPWMSYNCI (I)
ADCSOCAO (O)
3,2
GPIO33
SCLA (I/OC)
EPWMSYNCO (O)
ADCSOCBO (O)
5,4
GPIO34
COMP2OUT (O)
Reserved
Reserved
7,6
GPIO35 (TDI)
Reserved
Reserved
Reserved
9,8
GPIO36 (TMS)
Reserved
Reserved
Reserved
11,10
GPIO37 (TDO)
Reserved
Reserved
Reserved
13,12
GPIO38/XCLKIN (TCK)
Reserved
Reserved
Reserved
15,14
Reserved
Reserved
Reserved
Reserved
17,16
Reserved
Reserved
Reserved
Reserved
19,18
Reserved
Reserved
Reserved
Reserved
21,20
Reserved
Reserved
Reserved
Reserved
23,22
Reserved
Reserved
Reserved
Reserved
25,24
Reserved
Reserved
Reserved
Reserved
27,26
Reserved
Reserved
Reserved
Reserved
29,28
Reserved
Reserved
Reserved
Reserved
31,30
Reserved
Reserved
Reserved
Reserved
Table 59. Analog MUX
Default at Reset
AIOx and Peripheral Selection1
Peripheral Selection 2 and Peripheral
Selection 3
AIOMUX1 Register bits
AIOMUX1 bits = 0,x
AIOMUX1 bits = 1,x
1-0
ADCINA0 (I)
ADCINA0 (I)
3-2
ADCINA1 (I)
ADCINA1 (I)
5-4
AIO2 (I/O)
ADCINA2 (I), COMP1A (I)
7-6
ADCINA3 (I)
ADCINA3 (I)
9-8
AIO4 (I/O)
ADCINA4 (I), COMP2A (I)
11-10
ADCINA5 (I)
ADCINA5 (I)
13-12
AIO6 (I/O)
ADCINA6 (I), COMP3A (1)
15-14
ADCINA7 (I)
ADCINA7 (I)
17-16
ADCINB0 (I)
ADCINB0 (I)
19-18
ADCINB1 (I)
ADCINB1 (I)
21-20
AIO10 (I/O)
ADCINB2 (I), COMP1B (I)
23-22
ADCINB3 (I)
ADCINB3 (I)
25-24
AIO12 (I/O)
ADCINB4 (I), COMP2B (I)
27-26
ADCINB5 (I)
ADCINB5 (I)
29-28
AIO14 (I/O)
ADCINB6 (I), COMP3B (1)
31-30
ADCINB7 (I)
ADCINB7 (I)
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Register Bit Definitions
Figure 51. GPIO Port A MUX 1 (GPAMUX1) Register
31
26
15
14
25
24
23
16
Reserved
GPIO12
Reserved
R-0
R/W-0
R-0
13
12
11
10
9
8
7
6
5
4
3
2
1
0
GPIO7
GPIO6
GPIO5
GPIO4
GPIO3
GPIO2
GPIO1
GPIO0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND- R/W = Read/Write; R = Read only; -n = value after reset
Table 60. GPIO Port A Multiplexing 1 (GPAMUX1) Register Field Descriptions
Bits
(1)
Reserved
Reserved
GPIO12
Configure the GPIO12 pin as:
23-16
Reserved
15-14
GPIO7
9-8
7-6
84
Description
25-24
11-10
(2)
Value
31-26
13-12
(1)
Field
00
GPIO12 - General purpose I/O 12 (default) (I/O)
01
TZ1 - Trip zone 1 (I)
10
SCITXDA - SCI-A Transmit (O)
11
Reserved
Configure the GPIO7 pin as:
00
GPIO7 - General purpose I/O 7 (default) (I/O)
01
EPWM4B - ePWM4 output B (O)
10
SCIRXDA (I) - SCI-A Receive (I)
11
Reserved
GPIO6
Configure the GPIO6 pin as:
00
GPIO6 - General purpose I/O 6 (default)
01
EPWM4A - ePWM4 output A (O)
10
EPWMSYNCI - ePWM Synch-in (I)
11
EPWMSYNCO - ePWM Synch-out (O)
GPIO5
Configure the GPIO5 pin as:
00
GPIO5 - General purpose I/O 5 (default) (I/O)
01
EPWM3B - ePWM3 output B
10
Reserved
11
ECAP1 - eCAP1 (I/O)
GPIO4
Configure the GPIO4 pin as:
00
GPIO4 - General purpose I/O 4 (default) (I/O)
01
EPWM3A - ePWM3 output A (O)
10
Reserved.
(2)
11
Reserved.
(2)
GPIO3
Configure the GPIO3 pin as:
00
GPIO3 - General purpose I/O 3 (default) (I/O)
01
EPWM2B - ePWM2 output B (O)
10
Reserved
11
COMP2OUT (O)
This register is EALLOW protected. See Section 5.2 for more information.
If reserved configurations are selected, then the state of the pin will be undefined and the pin may be driven. These selections
are reserved for future expansion and should not be used.
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Table 60. GPIO Port A Multiplexing 1 (GPAMUX1) Register Field Descriptions (continued)
Bits
5-4
3-2
1-0
Field
Value
Description
GPIO2
(1)
Configure the GPIO2 pin as:
00
GPIO2 (I/O) General purpose I/O 2 (default) (I/O)
01
EPWM2A - ePWM2 output A (O)
10
Reserved.
(2)
11
Reserved.
(2)
GPIO1
Configure the GPIO1 pin as:
00
GPIO1 - General purpose I/O 1 (default) (I/O)
01
EPWM1B - ePWM1 output B (O)
10
Reserved
11
COMP1OUT (O) - Comparator 1 output
GPIO0
Configure the GPIO0 pin as:
00
GPIO0 - General purpose I/O 0 (default) (I/O)
01
EPWM1A - ePWM1 output A (O)
10
Reserved.
(2)
11
Reserved.
(2)
Figure 52. GPIO Port A MUX 2 (GPAMUX2) Register
31
28
27
Reserved
R/W-0
26
25
24
GPIO29
GPIO28
R/W-0
R/W-0
R/W-0
15
23
16
Reserved
R/W-0
8
7
R/W-0
6
5
R/W-0
4
3
R/W-0
2
1
0
Reserved
GPIO19
GPIO18
GPIO17
GPIO16
R-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 61. GPIO Port A MUX 2 (GPAMUX2) Register Field Descriptions
Bits
31-28
Reserved
27-26
GPIO29
25-24
(1)
Field
Value
Reserved
7-6
GPIO19/XCLKIN
(1)
Reserved
Configure the GPIO29 pin as:
00
GPIO29 (I/O) General purpose I/O 29 (default) (I/O)
01
SCITXDA - SCI-A transmit. (O)
10
SCLA (I/OC)
11
TZ3 - Trip zone 3(I)
GPIO28
23-8
Description
Configure the GPIO28 pin as:
00
GPIO28 (I/O) General purpose I/O 28 (default) (I/O)
01
SCIRXDA - SCI-A receive (I)
10
SDAA (I/OC)
11
TZ2 - Trip zone 2(I)
11
Reserved
Configure the GPIO19 pin as:
00
GPIO19 - General purpose I/O 19 (default) (I/O)
01
SPISTEA - SPI-A slave transmit enable (I/O)
10
SCIRXDA (I)
11
ECAP1 (I/O)
This register is EALLOW protected. See Section 5.2 for more information.
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Table 61. GPIO Port A MUX 2 (GPAMUX2) Register Field Descriptions (continued)
Bits
5-4
3-2
1-0
Field
Value
GPIO18
(1)
Description
Configure the GPIO18 pin as:
00
GPIO18 - General purpose I/O 18 (default) (I/O)
01
SPICLKA - SPI-A clock (I/O)
10
SCITXDA (O)
11
XCLKOUT (O) - External clock output
GPIO17
Configure the GPIO17 pin as:
00
GPIO17 - General purpose I/O 17 (default) (I/O)
01
SPISOMIA - SPI-A slave-out, master-in (I/O)
10
Reserved
11
TZ3 - Trip zone 3 (I)
GPIO16
Configure the GPIO16 pin as:
00
GPIO16 - General purpose I/O 16 (default) (I/O)
01
SPISIMOA - SPI-A slave-in, master-out (I/O),
10
Reserved
11
TZ2 - Trip zone 2 (I)
Figure 53. GPIO Port B MUX 1 (GPBMUX1) Register
31
16
Reserved
R-0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Reserved
GPIO38
GPIO37
GPIO36
GPIO35
GPIO34
GPIO33
GPIO32
R-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 62. GPIO Port B MUX 1 (GPBMUX1) Register Field Descriptions
Bit
Field
31-14
Reserved
13-12
GPIO38/XCLKIN/
TCK
11:10
9:8
7:6
86
Value
Configure this pin as:
00
GPIO 38 - general purpose I/O 38 (default) (I/O). If TRST = 1, JTAG TCK function is chosen for
this pin. This pin can also be used to provide a clock from an external oscillator to the core.
01
Reserved
10 or 11
Reserved
GPIO37/TDO
Configure this pin as:
00
GPIO 37 - general purpose I/O 37 (default). If TRST = 1, JTAG TDO function is chosen for this
pin.
01
Reserved
10 or 11
Reserved
GPIO36/TMS
Configure this pin as:
00
GPIO 36 - general purpose I/O 36 (default). If TRST = 1, JTAG TMS function is chosen for this
pin.
01
Reserved
10 or 11
Reserved
GPIO35/TDI
System Control
Description
Configure this pin as:
00
GPIO 35 - general purpose I/O 35 (default). If TRST = 1, JTAG TDI function is chosen for this
pin.
01
Reserved
10 or 11
Reserved
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Table 62. GPIO Port B MUX 1 (GPBMUX1) Register Field Descriptions (continued)
Bit
Field
5:4
GPIO34
3:2
Value
Description
Configure this pin as:
00
GPIO 34 - general purpose I/O 34 (default)
01
COMP2OUT (O)
10
Reserved
11
Reserved
GPIO33
1:0
Configure this pin as:
00
GPIO 33 - general purpose I/O 33 (default)
01
SCLA - I2C clock open drain bidirectional port (I/O)
10
EPWMSYNCO - External ePWM sync pulse output (O)
11
ADCSOCBO - ADC start-of-conversion B (O)
GPIO32
Configure this pin as:
00
GPIO 32 - general purpose I/O 32 (default)
01
SDAA - I2C data open drain bidirectional port (I/O)
10
EPWMSYNCI - External ePWM sync pulse input (I)
11
ADCSOCAO - ADC start-of-conversion A (O)
Figure 54. Analog I/O MUX (AIOMUX1) Register
31
30
29
28
27
26
25
24
23
22
21
20
19
16
Reserved
AIO14
Reserved
AIO12
Reserved
AIO10
Reserved
R-0
R/W-1,x
R-0
R/W-1,x
R-0
R/W-1,x
R-0
15
14
13
12
11
10
9
8
7
6
5
4
3
0
Reserved
AIO6
Reserved
AIO4
Reserved
AIO2
Reserved
R-0
R/W-1,x
R-0
R/W-1,x
R-0
R/W-1,x
R-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 63. Analog I/O MUX (AIOMUX1) Register Field Descriptions
Bit
Field
31:30
Reserved
29:28
AIO14
27:26
Reserved
25:24
AIO12
23:22
Reserved
21:20
AIO10
19:14
Reserved
13:12
AIO6
11:10
9:8
Value
Any writes to these bits must always have a value of 0.
00 or 01
AIO14 enabled
10 or 11
AIO14 disabled (default)
Any writes to these bits must always have a value of 0.
00 or 01
AIO12 enabled
10 or 11
AIO12 disabled (default)
Any writes to these bits must always have a value of 0.
00 or 01
AIO10 enabled
10 or 11
AIO10 disabled (default)
Any writes to these bits must always have a value of 0.
00 or 01
AIO6 enabled
10 or 11
AIO6 disabled (default)
Reserved
AIO4
7:6
Reserved
5:4
AIO2
Description
Any writes to these bits must always have a value of 0.
00 or 01
AIO4 enabled
10 or 11
AIO4 disabled (default)
Any writes to these bits must always have a value of 0.
00 or 01
AIO2 enabled
10 or 11
AIO2 disabled (default)
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Table 63. Analog I/O MUX (AIOMUX1) Register Field Descriptions (continued)
Bit
Field
3:0
Reserved
Value
Description
Any writes to these bits must always have a value of 0.
Figure 55. GPIO Port A Qualification Control (GPACTRL) Register
31
24
23
16
QUALPRD3
QUALPRD2
R/W-0
R/W-0
15
8
7
0
QUALPRD1
QUALPRD0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
The GPxCTRL registers specify the sampling period for input pins when configured for input qualification
using a window of 3 or 6 samples. The sampling period is the amount of time between qualification
samples relative to the period of SYSCLKOUT. The number of samples is specified in the GPxQSELn
registers.
Table 64. GPIO Port A Qualification Control (GPACTRL) Register Field Descriptions
Bits
Field
31-24
QUALPRD3
Value
0x01
Sampling Period = 2 × TSYSCLKOUT
0x02
Sampling Period = 4 × TSYSCLKOUT
QUALPRD2
0x01
Sampling Period = 2 × TSYSCLKOUT
0x02
Sampling Period = 4 × TSYSCLKOUT
QUALPRD1
...
Sampling Period = 510 × TSYSCLKOUT
Specifies the sampling period for pins GPIO8 to GPIO15.
(2)
0x00
Sampling Period = TSYSCLKOUT
0x01
Sampling Period = 2 × TSYSCLKOUT
0x02
Sampling Period = 4 × TSYSCLKOUT
...
QUALPRD0
...
Sampling Period = 510 × TSYSCLKOUT
Specifies the sampling period for pins GPIO0 to GPIO7.
(2)
0x00
Sampling Period = TSYSCLKOUT
0x01
Sampling Period = 2 × TSYSCLKOUT
0x02
Sampling Period = 4 × TSYSCLKOUT
...
0xFF
88
(2)
Sampling Period = TSYSCLKOUT
0xFF
(2)
Sampling Period = 510 × TSYSCLKOUT
Specifies the sampling period for pins GPIO16 to GPIO23.
0xFF
(1)
...
0x00
...
7-0
(2)
Sampling Period = TSYSCLKOUT
0xFF
15-8
(1)
Specifies the sampling period for pins GPIO24 to GPIO31.
0x00
...
23-16
Description
...
Sampling Period = 510 × TSYSCLKOUT
This register is EALLOW protected. See Section 5.2 for more information.
TSYSCLKOUT indicates the period of SYSCLKOUT.
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Figure 56. GPIO Port B Qualification Control (GPBCTRL) Register
31
16
Reserved
R-0
15
8
7
0
Reserved
QUALPRD0
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 65. GPIO Port B Qualification Control (GPBCTRL) Register Field Descriptions
Bits
Field
31- 8
Reserved
7-0
QUALPRD0
Value
Specifies the sampling period for pins GPIO32 to GPIO38
0xFF
Sampling Period = 510 × TSYSCLKOUT
0x00
Sampling Period = TSYSCLKOUT
0x01
Sampling Period = 2 × TSYSCLKOUT
0x02
Sampling Period = 4 × TSYSCLKOUT
0xFF
(2)
(1)
Reserved
...
(1)
Description
(2)
...
Sampling Period = 510 × TSYSCLKOUT
This register is EALLOW protected. See Section 5.2 for more information.
TSYSCLKOUT indicates the period of SYSCLKOUT.
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Figure 57. GPIO Port A Qualification Select 1 (GPAQSEL1) Register
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
GPIO15
GPIO14
GPIO13
GPIO12
GPIO11
GPIO10
GPIO9
GPIO8
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
GPIO7
GPIO6
GPIO5
GPIO4
GPIO3
GPIO2
GPIO1
GPIO0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 66. GPIO Port A Qualification Select 1 (GPAQSEL1) Register Field Descriptions
(1)
Bits
Field
Value
31-0
GPIO15-GPIO0
Description
(1)
Select input qualification type for GPIO0 to GPIO15. The input qualification of each GPIO
input is controlled by two bits as shown in Figure 57.
00
Synchronize to SYSCLKOUT only. Valid for both peripheral and GPIO pins.
01
Qualification using 3 samples. Valid for pins configured as GPIO or a peripheral function.
The time between samples is specified in the GPACTRL register.
10
Qualification using 6 samples. Valid for pins configured as GPIO or a peripheral function.
The time between samples is specified in the GPACTRL register.
11
Asynchronous. (no synchronization or qualification). This option applies to pins configured
as peripherals only. If the pin is configured as a GPIO input, then this option is the same as
0,0 or synchronize to SYSCLKOUT.
This register is EALLOW protected. See Section 5.2 for more information.
Figure 58. GPIO Port A Qualification Select 2 (GPAQSEL2) Register
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
GPIO31
GPIO30
GPIO29
GPIO28
GPIO27
GPIO26
GPIO25
GPIO24
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
GPIO23
GPIO22
GPIO21
GPIO20
GPIO19
GPIO18
GPIO17
GPIO16
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 67. GPIO Port A Qualification Select 2 (GPAQSEL2) Register Field Descriptions
(1)
90
Bits
Field
31-0
GPIO31-GPIO16
Value
Description
(1)
Select input qualification type for GPIO16 to GPIO31. The input qualification of each GPIO
input is controlled by two bits as shown in Figure 58.
00
Synchronize to SYSCLKOUT only. Valid for both peripheral and GPIO pins.
01
Qualification using 3 samples. Valid for pins configured as GPIO or a peripheral function. The
time between samples is specified in the GPACTRL register.
10
Qualification using 6 samples. Valid for pins configured as GPIO or a peripheral function. The
time between samples is specified in the GPACTRL register.
11
Asynchronous. (no synchronization or qualification). This option applies to pins configured as
peripherals only. If the pin is configured as a GPIO input, then this option is the same as 0,0
or synchronize to SYSCLKOUT.
This register is EALLOW protected. See Section 5.2 for more information.
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Figure 59. GPIO Port B Qualification Select 1 (GPBQSEL1) Register
31
16
Reserved
R-0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Reserved
GPIO38
GPIO37
GPIO36
GPIO35
GPIO34
GPIO33
GPIO32
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 68. GPIO Port B Qualification Select 1 (GPBQSEL1) Register Field Descriptions
Bits
(1)
Field
Value
31-14
Reserved
13 -0
GPIO38 -GPIO32
Description
(1)
Select input qualification type for GPIO32 to GPIO38 . The input qualification of each GPIO
input is controlled by two bits as shown in Figure 59.
00
Synchronize to SYSCLKOUT only. Valid for both peripheral and GPIO pins.
01
Qualification using 3 samples. Valid for pins configured as GPIO or a peripheral function.
The time between samples is specified in the GPACTRL register.
10
Qualification using 6 samples. Valid for pins configured as GPIO or a peripheral function.
The time between samples is specified in the GPACTRL register.
11
Asynchronous. (no synchronization or qualification). This option applies to pins configured
as peripherals only. If the pin is configured as a GPIO input, then this option is the same as
0,0 or synchronize to SYSCLKOUT.
This register is EALLOW protected. See Section 5.2 for more information.
The GPADIR and GPBDIR registers control the direction of the pins when they are configured as a GPIO
in the appropriate MUX register. The direction register has no effect on pins configured as peripheral
functions.
Figure 60. GPIO Port A Direction (GPADIR) Register
31
30
29
28
27
26
25
24
GPIO31
GPIO30
GPIO29
GPIO28
GPIO27
GPIO26
GPIO25
GPIO24
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
23
22
21
20
19
18
17
16
GPIO23
GPIO22
GPIO21
GPIO20
GPIO19
GPIO18
GPIO17
GPIO16
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
15
14
13
12
11
10
9
8
GPIO15
GPIO14
GPIO13
GPIO12
GPIO11
GPIO10
GPIO9
GPIO8
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
7
6
5
4
3
2
1
0
GPIO7
GPIO6
GPIO5
GPIO4
GPIO3
GPIO2
GPIO1
GPIO0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 69. GPIO Port A Direction (GPADIR) Register Field Descriptions
Bits
Field
31-0
GPIO31-GPIO0
Value
Description
(1)
Controls direction of GPIO Port A pins when the specified pin is configured as a GPIO in the
appropriate GPAMUX1 or GPAMUX2 register.
0
Configures the GPIO pin as an input. (default)
1
Configures the GPIO pin as an output
The value currently in the GPADAT output latch is driven on the pin. To initialize the GPADAT
latch prior to changing the pin from an input to an output, use the GPASET, GPACLEAR, and
GPATOGGLE registers.
(1)
This register is EALLOW protected. See Section 5.2 for more information.
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Figure 61. GPIO Port B Direction (GPBDIR) Register
31
8
Reserved
R-0
7
6
5
4
3
2
1
0
GPIO38
GPIO37
GPIO36
GPIO35
GPIO34
GPIO33
GPIO32
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 70. GPIO Port B Direction (GPBDIR) Register Field Descriptions
(1)
Value
Description
(1)
Bits
Field
31-7
Reserved
Reserved
6 -0
GPIO38 -GPIO32
Controls direction of GPIO pin when GPIO mode is selected. Reading the register returns the
current value of the register setting
0
Configures the GPIO pin as an input. (default)
1
Configures the GPIO pin as an output
This register is EALLOW protected. See Section 5.2 for more information.
Figure 62. Analog I/O DIR (AIODIR) Register
31
16
Reserved
R-0
15
14
13
12
11
10
Reserved
AIO14
Reserved
AIO12
Reserved
AIO10
9
Reserved
8
R-0
R/W-x
R-0
R/W-x
R-0
R/W-x
R-0
7
6
5
4
3
2
Reserved
AIO6
Reserved
AIO4
Reserved
AIO2
1
Reserved
0
R-0
R/W-x
R-0
R/W-x
R-0
R/W-x
R-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 71. Analog I/O DIR (AIODIR) Register Field Descriptions
Bit
Field
31:15
Reserved
14:0
AIOn
Value
Description
Controls direction of the avaliable AIO pin when AIO mode is selected. Reading the register returns
the current value of the register setting
0
Configures the AIO pin as an input. (default)
1
Configures the AIO pin as an output
The pullup disable (GPxPUD) registers allow you to specify which pins should have an internal pullup
resister enabled. The internal pullups on the pins that can be configured as ePWM outputs(GPIO0GPIO11) are all disabled asynchronously when the external reset signal (XRS) is low. The internal pullups
on all other pins are enabled on reset. When coming out of reset, the pullups remain in their default state
until you enable or disable them selectively in software by writing to this register. The pullup configuration
applies both to pins configured as I/O and those configured as peripheral functions.
92
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Figure 63. GPIO Port A Pullup Disable (GPAPUD) Registers
31
30
29
28
27
26
25
24
GPIO31
GPIO30
GPIO29
GPIO28
GPIO27
GPIO26
GPIO25
GPIO24
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
23
22
21
20
19
18
17
16
GPIO23
GPIO22
GPIO21
GPIO20
GPIO19
GPIO18
GPIO17
GPIO16
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
15
14
13
12
11
10
9
8
GPIO15
GPIO14
GPIO13
GPIO12
GPIO11
GPIO10
GPIO9
GPIO8
R/W-0
R/W-0
R/W-0
R/W-0
R/W-1
R/W-1
R/W-1
R/W-1
7
6
5
4
3
2
1
0
GPIO7
GPIO6
GPIO5
GPIO4
GPIO3
GPIO2
GPIO1
GPIO0
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 72. GPIO Port A Internal Pullup Disable (GPAPUD) Register Field Descriptions
(1)
Bits
Field
Value
31-0
GPIO31-GPIO0
(1)
Description
Configure the internal pullup resister on the selected GPIO Port A pin. Each GPIO pin
corresponds to one bit in this register.
0
Enable the internal pullup on the specified pin. (default for GPIO12-GPIO31)
1
Disable the internal pullup on the specified pin. (default for GPIO0-GPIO11)
This register is EALLOW protected. See Section 5.2 for more information.
Figure 64. GPIO Port B Pullup Disable (GPBPUD) Registers
31
8
Reserved
R-0
7
6
5
4
3
2
1
0
Reserved
GPIO38
GPIO37
GPIO36
GPIO35
GPIO34
GPIO33
GPIO32
R-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 73. GPIO Port B Internal Pullup Disable (GPBPUD) Register Field Descriptions
(1)
Value
Description
(1)
Bits
Field
31-7
Reserved
Reserved
6 -0
GPIO38 GPIO32
Configure the internal pullup resister on the selected GPIO Port B pin. Each GPIO pin
corresponds to one bit in this register.
0
Enable the internal pullup on the specified pin. (default)
1
Disable the internal pullup on the specified pin.
This register is EALLOW protected. See Section 5.2 for more information.
The GPIO data registers indicate the current status of the GPIO pin, irrespective of which mode the pin is
in. Writing to this register will set the respective GPIO pin high or low if the pin is enabled as a GPIO
output, otherwise the value written is latched but ignored. The state of the output register latch will remain
in its current state until the next write operation. A reset will clear all bits and latched values to zero. The
value read from the GPxDAT registers reflect the state of the pin (after qualification), not the state of the
output latch of the GPxDAT register.
Typically the DAT registers are used for reading the current state of the pins. To easily modify the output
level of the pin refer to the SET, CLEAR and TOGGLE registers.
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Figure 65. GPIO Port A Data (GPADAT) Register
31
30
29
28
27
26
25
24
GPIO31
GPIO30
GPIO29
GPIO28
GPIO27
GPIO26
GPIO25
GPIO24
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
23
22
21
20
19
18
17
16
GPIO23
GPIO22
GPIO21
GPIO20
GPIO19
GPIO18
GPIO17
GPIO16
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
15
14
13
12
11
10
9
8
GPIO15
GPIO14
GPIO13
GPIO12
GPIO11
GPIO10
GPIO9
GPIO8
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
7
6
5
4
3
2
1
0
GPIO7
GPIO6
GPIO5
GPIO4
GPIO3
GPIO2
GPIO1
GPIO0
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset (1)
(1)
x = The state of the GPADAT register is unknown after reset. It depends on the level of the pin after reset.
Table 74. GPIO Port A Data (GPADAT) Register Field Descriptions
Bits
Field
31-0
GPIO31-GPIO0
Value
Description
Each bit corresponds to one GPIO port A pin (GPIO0-GPIO31) as shown in Figure 65.
0
Reading a 0 indicates that the state of the pin is currently low, irrespective of the mode the pin is
configured for.
Writing a 0 will force an output of 0 if the pin is configured as a GPIO output in the appropriate
GPAMUX1/2 and GPADIR registers; otherwise, the value is latched but not used to drive the
pin.
1
Reading a 1 indicates that the state of the pin is currently high irrespective of the mode the pin
is configured for.
Writing a 1will force an output of 1if the pin is configured as a GPIO output in the appropriate
GPAMUX1/2 and GPADIR registers; otherwise, the value is latched but not used to drive the
pin.
Figure 66. GPIO Port B Data (GPBDAT) Register
31
8
Reserved
R-0
7
6
5
4
3
2
1
0
Reserved
GPIO38
GPIO37
GPIO36
GPIO35
GPIO34
GPIO33
GPIO32
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
(1)
(1)
x = The state of the GPADAT register is unknown after reset. It depends on the level of the pin after reset.
Table 75. GPIO Port B Data (GPBDAT) Register Field Descriptions
Bit
Field
31-7
Reserved
6 -0
GPIO38 -GPIO32
Value
Description
Each bit corresponds to one GPIO port B pin (GPIO32-GPIO38 ) as shown in Figure 66.
0
Reading a 0 indicates that the state of the pin is currently low, irrespective of the mode the pin is
configured for.
Writing a 0 will force an output of 0 if the pin is configured as a GPIO output in the appropriate
GPBMUX1 and GPBDIR registers; otherwise, the value is latched but not used to drive the pin.
1
Reading a 1 indicates that the state of the pin is currently high irrespective of the mode the pin is
configured for.
Writing a 1 will force an output of 1 if the pin is configured as a GPIO output in the GPBMUX1
and GPBDIR registers; otherwise, the value is latched but not used to drive the pin.
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Figure 67. Analog I/O DAT (AIODAT) Register
31
16
Reserved
R-0
15
14
13
12
11
10
Reserved
AIO14
Reserved
AIO12
Reserved
AIO10
9
Reserved
8
R-0
R/W-x
R-0
R/W-x
R-0
R/W-x
R-0
7
6
5
4
3
2
Reserved
AIO6
Reserved
AIO4
Reserved
AIO2
1
Reserved
0
R-0
R/W-x
R-0
R/W-x
R-0
R/W-x
R-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 76. Analog I/O DAT (AIODAT) Register Field Descriptions
Bit
Field
31:15
Reserved
14-0
AIOn
Value
Description
Each bit corresponds to one AIO port pin
0
Reading a 0 indicates that the state of the pin is currently low, irrespective of the mode the pin is
configured for.
Writing a 0 will force an output of 0 if the pin is configured as a AIO output in the appropriate
registers; otherwise, the value is latched but not used to drive the pin.
1
Reading a 1 indicates that the state of the pin is currently high irrespective of the mode the pin is
configured for.
Writing a 1will force an output of 1if the pin is configured as a AIO output in the appropriate
registers; otherwise, the value is latched but not used to drive the pin.
Figure 68. GPIO Port A Set, Clear and Toggle (GPASET, GPACLEAR, GPATOGGLE) Registers
31
30
29
28
27
26
25
24
GPIO31
GPIO30
GPIO29
GPIO28
GPIO27
GPIO26
GPIO25
GPIO24
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
23
22
21
20
19
18
17
16
GPIO23
GPIO22
GPIO21
GPIO20
GPIO19
GPIO18
GPIO17
GPIO16
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
15
14
13
12
11
10
9
8
GPIO15
GPIO14
GPIO13
GPIO12
GPIO11
GPIO10
GPIO9
GPIO8
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
7
6
5
4
3
2
1
0
GPIO7
GPIO6
GPIO5
GPIO4
GPIO3
GPIO2
GPIO1
GPIO0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 77. GPIO Port A Set (GPASET) Register Field Descriptions
Bits
Field
31-0
GPIO31-GPIO0
Value
Description
Each GPIO port A pin (GPIO0-GPIO31) corresponds to one bit in this register as shown in
Figure 68.
0
Writes of 0 are ignored. This register always reads back a 0.
1
Writing a 1 forces the respective output data latch to high. If the pin is configured as a GPIO
output then it will be driven high. If the pin is not configured as a GPIO output then the latch is set
high but the pin is not driven.
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Table 78. GPIO Port A Clear (GPACLEAR) Register Field Descriptions
Bits
Field
31-0
GPIO31 - GPIO0
Value
Description
Each GPIO port A pin (GPIO0-GPIO31) corresponds to one bit in this register as shown in
Figure 68.
0
Writes of 0 are ignored. This register always reads back a 0.
1
Writing a 1 forces the respective output data latch to low. If the pin is configured as a GPIO output
then it will be driven low. If the pin is not configured as a GPIO output then the latch is cleared but
the pin is not driven.
Table 79. GPIO Port A Toggle (GPATOGGLE) Register Field Descriptions
Bits
Field
31-0
Value
GPIO31-GPIO0
Description
Each GPIO port A pin (GPIO0-GPIO31) corresponds to one bit in this register as shown in
Figure 68.
0
Writes of 0 are ignored. This register always reads back a 0.
1
Writing a 1 forces the respective output data latch to toggle from its current state. If the pin is
configured as a GPIO output then it will be driven in the opposite direction of its current state. If the
pin is not configured as a GPIO output then the latch is toggled but the pin is not driven.
Figure 69. GPIO Port B Set, Clear and Toggle (GPBSET, GPBCLEAR, GPBTOGGLE) Registers
31
8
Reserved
R-0
7
6
5
4
3
2
1
0
Reserved
GPIO38
GPIO37
GPIO36
GPIO35
GPIO34
GPIO33
GPIO32
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 80. GPIO Port B Set (GPBSET) Register Field Descriptions
Bits
Field
Value
31-7
Reserved
6 -0
GPIO38 -GPIO32
Description
Each GPIO port B pin (GPIO32-GPIO38 ) corresponds to one bit in this register as shown in
Figure 69.
0
Writes of 0 are ignored. This register always reads back a 0.
1
Writing a 1 forces the respective output data latch to high. If the pin is configured as a GPIO
output then it will be driven high. If the pin is not configured as a GPIO output then the latch is
set but the pin is not driven.
Table 81. GPIO Port B Clear (GPBCLEAR) Register Field Descriptions
Bits
96
Field
31-7
Reserved
6 -0
GPIO38 -GPIO32
System Control
Value
Description
Each GPIO port B pin (GPIO32-GPIO38 ) corresponds to one bit in this register as shown in
Figure 69.
0
Writes of 0 are ignored. This register always reads back a 0.
1
Writing a 1 forces the respective output data latch to low. If the pin is configured as a GPIO
output then it will be driven low. If the pin is not configured as a GPIO output then the latch is
cleared but the pin is not driven.
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Table 82. GPIO Port B Toggle (GPBTOGGLE) Register Field Descriptions
Bits
Field
Value
31-7
Reserved
6 -0
GPIO38 -GPIO32
Description
Each GPIO port B pin (GPIO32-GPIO38 ) corresponds to one bit in this register as shown in
Figure 69.
0
Writes of 0 are ignored. This register always reads back a 0.
1
Writing a 1 forces the respective output data latch to toggle from its current state. If the pin is
configured as a GPIO output then it will be driven in the opposite direction of its current state. If
the pin is not configured as a GPIO output then the latch is cleared but the pin is not driven.
Figure 70. Analog I/O Toggle (AIOSET, AIOCLEAR, AIOTOGGLE) Register
31
16
Reserved
R-0
15
14
13
12
11
10
Reserved
AIO14
Reserved
AIO12
Reserved
AIO10
9
Reserved
8
R-0
R/W-x
R-0
R/W-x
R-0
R/W-x
R-0
7
6
5
4
3
2
Reserved
AIO6
Reserved
AIO4
Reserved
AIO2
1
Reserved
0
R-0
R/W-x
R-0
R/W-x
R-0
R/W-x
R-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 83. Analog I/O Set (AIOSET) Register Field Descriptions
Bits
Field
31-15
Reserved
14-0
AIOn
Value
Description
Each AIO pin corresponds to one bit in this register.
0
Writes of 0 are ignored. This register always reads back a 0.
1
Writing a 1 forces the respective output data latch to high. If the pin is configured as a AIO output
then it will be driven high. If the pin is not configured as a AIO output then the latch is set but the
pin is not driven.
Table 84. Analog I/O Clear (AIOCLEAR) Register Field Descriptions
Bits
Field
31-15
Reserved
14-0
AIOn
Value
Description
Each AIO pin corresponds to one bit in this register.
0
Writes of 0 are ignored. This register always reads back a 0.
1
Writing a 1 forces the respective output data latch to low. If the pin is configured as a AIO output
then it will be driven low. If the pin is not configured as a AIO output then the latch is cleared but
the pin is not driven.
Table 85. Analog I/O Toggle (AIOTOGGLE) Register Field Descriptions
Bits
Field
31-15
Reserved
14-0
AIOn
Value
Description
Each AIO pin corresponds to one bit in this register.
0
Writes of 0 are ignored. This register always reads back a 0.
1
Writing a 1 forces the respective output data latch to toggle from its current state. If the pin is
configured as a AIO output then it will be driven in the opposite direction of its current state. If
the pin is not configured as a AIO output then the latch is cleared but the pin is not driven.
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Figure 71. GPIO XINTn Interrupt Select (GPIOXINTnSEL) Registers
15
5
4
0
Reserved
GPIOXINTnSEL
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 86. GPIO XINTn Interrupt Select (GPIOXINTnSEL) (1) Register Field Descriptions
Bits
Field
Value
Description
15-5
Reserved
Reserved
4-0
GPIOXINTnSEL
Select the port A GPIO signal (GPIO0 - GPIO31) that will be used as the XINT1, XINT2, or
XINT3 interrupt source. In addition, you can configure the interrupt in the XINT1CR, XINT2CR,
or XINT3CR registers described in Section 6.6.
To use XINT2 as ADC start of conversion, enable it in the desired ADCSOCxCTL register.
The ADCSOC signal is always rising edge sensitive.
00000
Select the GPIO0 pin as the XINTn interrupt source (default)
00001
Select the GPIO1 pin as the XINTn interrupt source
...
(1)
(2)
(2)
...
11110
Select the GPIO30 pin as the XINTn interrupt source
11111
Select the GPIO31 pin as the XINTn interrupt source
n = 1 or 2
This register is EALLOW protected. See Section 5.2 for more information.
Table 87. XINT1/XINT2/XINT3 Interrupt Select and Configuration Registers
n
Interrupt
Interrupt Select Register
Configuration Register
1
XINT1
GPIOXINT1SEL
XINT1CR
2
XINT2
GPIOXINT2SEL
XINT2CR
3
XINT3
GPIOXINT3SEL
XINT3CR
Figure 72. GPIO Low Power Mode Wakeup Select (GPIOLPMSEL) Register
31
30
29
28
27
26
25
24
GPIO31
GPIO30
GPIO29
GPIO28
GPIO27
GPIO26
GPIO25
GPIO24
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
23
22
21
20
19
18
17
16
GPIO23
GPIO22
GPIO21
GPIO20
GPIO19
GPIO18
GPIO17
GPIO16
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
15
14
13
12
11
10
9
8
GPIO15
GPIO14
GPIO13
GPIO12
GPIO11
GPIO10
GPIO9
GPIO8
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
7
6
5
4
3
2
1
0
GPIO7
GPIO6
GPIO5
GPIO4
GPIO3
GPIO2
GPIO1
GPIO0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
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Table 88. GPIO Low Power Mode Wakeup Select (GPIOLPMSEL) Register Field Descriptions
Bits
31-0
(1)
Field
Value
GPIO31 - GPIO0
Description
(1)
Low Power Mode Wakeup Selection. Each bit in this register corresponds to one GPIO port
A pin (GPIO0 - GPIO31) as shown in Figure 72.
0
If the bit is cleared, the signal on the corresponding pin will have no effect on the HALT and
STANDBY low power modes.
1
If the respective bit is set to 1, the signal on the corresponding pin is able to wake the
device from both HALT and STANDBY low power modes.
This register is EALLOW protected. See Section 5.2 for more information.
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Peripheral Frames
This chapter describes the peripheral frames. It also describes the device emulation registers.
5.1
Peripheral Frame Registers
The 2802x devices contain four peripheral register spaces. The spaces are categorized as follows:
• Peripheral Frame 0: These are peripherals that are mapped directly to the CPU memory bus. See
Table 89.
• Peripheral Frame 1: These are peripherals that are mapped to the 32-bit peripheral bus. See Table 90.
• Peripheral Frame 2: These are peripherals that are mapped to the 16-bit peripheral bus. See Table 91.
Table 89. Peripheral Frame 0 Registers (1)
Name
Device Emulation Registers
Access Type
(2)
Address Range
Size (x16)
0x00 0880 - 0x00 0984
261
EALLOW protected
System Power Control Registers
0x00 0985 - 0x00 0987
3
EALLOW protected
FLASH Registers (3)
0x00 0A80 - 0x00 0ADF
96
EALLOW protected
Code Security Module Registers
0x00 0AE0 - 0x00 0AEF
16
EALLOW protected
ADC registers (dual-mapped) (0
wait, read only, CPU )
0x00 0B00 - 0x00 0B1F
32
Not EALLOW protected
CPU–TIMER0/1/2 Registers
0x00 0C00 - 0x00 0C3F
64
Not EALLOW protected
PIE Registers
0x00 0CE0 - 0x00 0CFF
32
Not EALLOW protected
PIE Vector Table
0x00 0D00 - 0x00 0DFF
256
EALLOW protected
(1)
(2)
(3)
Registers in Frame 0 support 16-bit and 32-bit accesses.
If registers are EALLOW protected, then writes cannot be performed until the EALLOW instruction is executed. The EDIS
instruction disables writes to prevent stray code or pointers from corrupting register contents.
The Flash Registers are also protected by the Code Security Module (CSM).
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Table 90. Peripheral Frame 1 Registers
Name
Address Range
(1)
Size (x16)
Access Type
Comparator1 Registers
0x6400 - 0x641F
32
Comparator2 Registers
0x6420 - 0x643F
32
(3)
ePWM1 + HRPWM1 Registers
0x6800 - 0x683F
64
(3)
ePWM2 + HRPWM2 Registers
0x6840 - 0x687F
64
(3)
ePWM3 + HRPWM3 Registers
0x6880 - 0x68BF
64
(3)
ePWM4 + HRPWM4 Registers
0x68C0 - 0x68FF
64
(3)
eCAP1 Registers
0x6A00 - 0x6A1F
32
Not EALLOW-protected
GPIO Control Registers
0x6F80 - 0x6FBF
128
EALLOW-protected
GPIO Data Registers
0x6FC0 - 0x6FDF
32
Not EALLOW-protected
GPIO Interrupt and LPM Select
Registers
0x6FE0 - 0x6FFF
32
EALLOW-protected
(1)
(2)
(3)
.
(2)
(3)
Back-to-back write operations to Peripheral Frame 1 registers will incur a 1-cycle stall (1 cycle delay).
Peripheral Frame 1 allows 16-bit and 32-bit accesses. All 32-bit accesses are aligned to even address boundaries.
Some Registers/Bits are EALLOW protected. See the module reference guide for more information.
Table 91. Peripheral Frame 2 Registers
Address Range
Size (x16)
System Control Registers
0x7010 - 0x702F
32
EALLOW-protected
SPI-A Registers
0x7040 - 0x704F
16
Not EALLOW protected
SCI-A Registers
0x7050 - 0x705F
16
Not EALLOW protected
NMI Watchdog Interrupt Registers
0x7060 - 0x706F
16
External Interrupt Registers
0x7070 - 0x707F
16
Not EALLOW protected
ADC Registers
0x7100 - 0x711F
32
Not EALLOW protected
I2C Registers
0x7900 - 0x793F
64
Not EALLOW protected
(1)
Access Type
(1)
Name
Peripheral Frame 2 only allows 16-bit accesses. All 32-bit accesses are ignored (invalid data can be returned or written).
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EALLOW-Protected Registers
Several control registers are protected from spurious CPU writes by the EALLOW protection mechanism.
The EALLOW bit in status register 1 (ST1) indicates if the state of protection as shown in Table 92.
Table 92. Access to EALLOW-Protected Registers
(1)
EALLOW Bit
CPU Writes
CPU Reads
JTAG Writes
JTAG Reads
0
Ignored
Allowed
Allowed (1)
Allowed
1
Allowed
Allowed
Allowed
Allowed
The EALLOW bit is overridden via the JTAG port, allowing full access of protected registers during debug from the Code
Composer Studio interface.
At reset the EALLOW bit is cleared enabling EALLOW protection. While protected, all writes to protected
registers by the CPU are ignored and only CPU reads, JTAG reads, and JTAG writes are allowed. If this
bit is set, by executing the EALLOW instruction, then the CPU is allowed to write freely to protected
registers. After modifying registers, they can once again be protected by executing the EDI instruction to
clear the EALLOW bit.
The following registers are EALLOW-protected:
• Device Emulation Registers
• Flash Registers
• CSM Registers
• PIE Vector Table
• System Control Registers
• GPIO MUX Registers
Table 93. EALLOW-Protected Device Emulation Registers
Name
DEVICECNF
Address
Size
(x16)
0x0880
0x0881
2
Description
Device Configuration Register
Table 94. EALLOW-Protected Flash/OTP Configuration Registers
Name
Address
Size
(x16)
FOPT
0x0A80
1
Flash Option Register
FPWR
0x0A82
1
Flash Power Modes Register
FSTATUS
0x0A83
1
Status Register
FSTDBYWAIT
0x0A84
1
Flash Sleep To Standby Wait State Register
FACTIVEWAIT
0x0A85
1
Flash Standby To Active Wait State Register
FBANKWAIT
0x0A86
1
Flash Read Access Wait State Register
FOTPWAIT
0x0A87
1
OTP Read Access Wait State Register
102 System Control
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Table 95. EALLOW-Protected Code Security Module (CSM) Registers
Register Name
Address
Size
(x16)
KEY0
0x0AE0
1
Low word of the 128-bit KEY register
KEY1
0x0AE1
1
Second word of the 128-bit KEY register
KEY2
0x0AE2
1
Third word of the 128-bit KEY register
KEY3
0x0AE3
1
Fourth word of the 128-bit KEY register
KEY4
0x0AE4
1
Fifth word of the 128-bit KEY register
KEY5
0x0AE5
1
Sixth word of the 128-bit KEY register
KEY6
0x0AE6
1
Seventh word of the 128-bit KEY register
KEY7
0x0AE7
1
High word of the 128-bit KEY register
CSMSCR
0x0AEF
1
CSM status and control register
Register Description
Table 96. EALLOW-Protected PLL, Clocking, Watchdog, and Low-Power Mode Registers
Name
Address
Size
(x16)
Description
XCLK
0x0000-7010
1
XCLKOUT/XCLKIN Control
PLLSTS
0x0000-7011
1
PLL Status Register
CLKCTL
0x0000-7012
1
Clock Control Register
PLLLOCKPRD
0x0000-7013
1
PLL Lock Period Register
INTOSC1TRIM
0x0000-7014
1
Internal Oscillator 1 Trim Register
INTOSC2TRIM
0x0000-7016
1
Internal Oscillator 2 Trim Register
LOSPCP
0x0000-701B
1
Low-Speed Peripheral Clock Pre-Scaler Register
PCLKCR0
0x0000-701C
1
Peripheral Clock Control Register 0
PCLKCR1
0x0000-701D
1
Peripheral Clock Control Register 1
LPMCR0
0x0000-701E
1
Low Power Mode Control Register 0
PCLKCR3
0x0000-7020
1
Peripheral Clock Control Register 3
PLLCR
0x0000-7021
1
PLL Control Register
SCSR
0x0000-7022
1
System Control and Status Register
WDCNTR
0x0000-7023
1
Watchdog Counter Register
WDKEY
0x0000-7025
1
Watchdog Reset Key Register
WDCR
0x0000-7029
1
Watchdog Control Register
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Table 97. EALLOW-Protected GPIO Registers
Name
(1)
Address
Size (x16)
GPACTRL
0x6F80
2
GPIO A Control Register
GPAQSEL1
0x6F82
2
GPIO A Qualifier Select 1 Register
GPAQSEL2
0x6F84
2
GPIO A Qualifier Select 2 Register
GPAMUX1
0x6F86
2
GPIO A MUX 1 Register
GPAMUX2
0x6F88
2
GPIO A MUX 2 Register
GPADIR
0x6F8A
2
GPIO A Direction Register
GPAPUD
0x6F8C
2
GPIO A Pull Up Disable Register
GPBCTRL
0x6F90
2
GPIO B Control Register
GPBQSEL1
0x6F92
2
GPIO B Qualifier Select 1 Register
GPBMUX1
0x6F96
2
GPIO B MUX 1 Register
GPBMUX2
0x6F98
2
GPIO B MUX 2 Register
GPBDIR
0x6F9A
2
GPIO B Direction Register
GPBPUD
0x6F9C
2
GPIO B Pull Up Disable Register
AIOMUX1
0x6FB6
2
Analog, I/O MUX 1 register
AIODIR
0x6FBA
2
Analog, IO Direction Register
GPIOXINT1SEL
0x6FE0
1
XINT1 Source Select Register (GPIO0-GPIO31)
GPIOXINT2SEL
0x6FE1
1
XINT2 Source Select Register (GPIO0-GPIO31)
GPIOXINT3SEL
0x6FE2
1
XINT3 Source Select Register (GPIO0 - GPIO31)
GPIOLPMSEL
0x6FE8
1
LPM wakeup Source Select Register (GPIO0-GPIO31)
(1)
Register Description
The registers in this table are EALLOW protected. See Section 5.2 for more information.
Table 99 shows addresses for the following ePWM EALLOW-protected registers:
• Trip Zone Select Register (TZSEL)
• Trip Zone Control Register (TZCTL)
• Trip Zone Enable Interrupt Register (TZEINT)
• Trip Zone Clear Register (TZCLR)
• Trip Zone Force Register (TZFRC)
• HRPWM Configuration Register (HRCNFG)
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Table 98. EALLOW-Protected PIE Vector Table
Name
Address
Size
(x16)
Not used
0x0D00
2
Reserved
Description
0x0D02
0x0D04
0x0D06
0x0D08
0x0D0A
0x0D0C
0x0D0E
0x0D10
0x0D12
0x0D14
0x0D16
0x0D18
INT13
0x0D1A
2
External Interrupt 13 (XINT13) or
CPU-Timer 1 (for RTOS use)
INT14
0x0D1C
2
CPU-Timer 2 (for RTOS use)
DATALOG
0x0D1E
2
CPU Data Logging Interrupt
RTOSINT
0x0D20
2
CPU Real-Time OS Interrupt
EMUINT
0x0D22
2
CPU Emulation Interrupt
NMI
0x0D24
2
External Non-Maskable Interrupt
ILLEGAL
0x0D26
2
Illegal Operation
USER1
0x0D28
2
User-Defined Trap
.
.
.
.
USER12
0x0D3E
2
User-Defined Trap
INT1.1
.
INT1.8
0x0D40
.
0x0D4E
2
.
2
Group 1 Interrupt Vectors
.
.
.
.
.
.
Group 2 Interrupt Vectors
to Group 11 Interrupt Vectors
0x0DF0
.
0x0DFE
2
.
2
Group 12 Interrupt Vectors
.
.
.
INT12.1
.
INT12.8
Table 99. EALLOW-Protected ePWM1 - ePWM4 Registers
TZSEL
TZCTL
TZEINT
TZCLR
TZFRC
HRCNFG
Size x16
ePWM1
0x6812
0x6814
0x6815
0x6817
0x6818
0x6820
1
ePWM2
0x6852
0x6854
0x6855
0x6857
0x6858
0x6860
1
ePWM3
0x6892
0x6894
0x6895
0x6897
0x6898
0x68A0
1
ePWM4
0x68D2
0x68D4
0x68D5
0x68D7
0x68D8
0x68E0
1
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Device Emulation Registers
These registers are used to control the protection mode of the C28x CPU and to monitor some critical
device signals. The registers are defined in Table 100.
Table 100. Device Emulation Registers
Name
DEVICECNF
PARTID
Address
Size (x16)
0x0880
0x0881
2
Description
Device Configuration Register
0x3D7FFF
1
Part ID Register
CLASSID
0x0882
1
Class ID Register
REVID
0x0883
1
Revision ID Register
Figure 73. Device Configuration (DEVICECNF) Register
31
27
26
20
19
18
16
Reserved
TRST
Reserved
ENPROT
Reserved
R-0
R-0
R-0
R/W-1
R-111
15
5
4
3
Reserved
XRS
Res
VMAPS
2
Reserved
0
R-0
R-P
R-0
R-1
R-011
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 101. DEVICECNF Register Field Descriptions
Bits
Field
31-28
27
Reserved
19
ENPROT
Read status of TRST signal. Reading this bit gives the current status of the TRST signal.
0
No emulator is connected.
1
An emulator is connected.
Enable Write-Read Protection Mode Bit.
0
Disables write-read protection mode
1
Enables write-read protection for the address range 0x4000-0x7FFF
Reserved
Reserved
5
XRS
Reset Input Signal Status. This is connected directly to the XRS input pin.
4
Reserved
Reserved
3
VMAPS
VMAP Configure Status. This indicates the status of VMAP.
Reserved
Reserved
2-0
106
Description
Reserved
TRST
26:20
18-6
Value
Reserved
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Figure 74. Part ID Register
15
8
7
0
PARTTYPE
PARTNO
R
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
R
Table 102. PARTID Register Field Descriptions
Bit
15:8
Field
(1)
Value
PARTTYPE
Description
These 8 bits specify the type of device such as flash-based.
0x00
Flash-based device
All other values are reserved.
7:0
(1)
PARTNO
These 8 bits specify the feature set of the device as follows:
00CF
TMS320F28027PT
0xCE
TMS320F28027DA
0xC7
TMS320F28026PT
0xC6
TMS320F28026DA
0xCD
TMS320F28023PT
0xCC
TMS320F28023DA
0xC5
TMS320F28022PT
0xC4
TMS320F28022DA
0xCB
TMS320F28021PT
0xCA
TMS320F28021DA
0xC3
TMS320F28020PT
0xC2
TMS320F28020DA
0xC1
TMS320F280200PT
0xC0
TMS320F280200DA
0x04
TMS320F280220DA
0x05
TMS320F280220PT
0x0C
TMS320F280230DA
0x0D
TMS320F280230PT
0x06
TMS320F280260DA
0x07
TMS320F280260PT
0x0E
TMS320F280270DA
0x0F
TMS320F280270PT
The reset value depends on the device as indicated in the register description.
Table 103. CLASSID Register Field Descriptions
Bit
7:0
(1)
Field
Value
(1)
CLASSID
Description
These 8 bits specify the feature set of the
device as follows:
0xCF
TMS320F28027
0xC7
TMS320F28026
0xCF
TMS320F28023
0xC7
TMS320F28022
0xCF
TMS320F28021
0xC7
TMS320F28020
0xC7
TMS320F280200/220/230/260/270
The reset value depends on the device as indicated in the register description.
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Figure 75. REVID Register
15
0
REVID
R
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 104. REVID Register Field Descriptions
Bits
15-0
(1)
108
Field
Value
Description
(1)
REVID
These 16 bits specify the silicon revision number for the particular part. This number always
starts with 0x0000 on the first revision of the silicon and is incremented on any subsequent
revisions.
0x0000
Silicon Revision 0 - This silicon revision is available as TMP and TMS.
0x0001
Silicon Revision A - TMS
The reset value depends on the silicon revision as described in the register field description.
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5.4
Write-Followed-by-Read Protection
The memory address range for which CPU write followed by read operations are protected is 0x4000 0x7FFF (operations occur in sequence rather then in their natural pipeline order). This is necessary
protection for certain peripheral operations.
Example: The following lines of code perform a write to register 1 (REG1) location and then the next
instruction performs a read from Register 2 (REG2) location. On the processor memory bus, with block
protection disabled, the read operation is issued before the write as shown.
MOV @REG1,AL
TBIT @REG2,#BIT_X
---------+
---------|-------> Read
+-------> Write
If block protection is enabled, then the read is stalled until the write occurs as shown:
MOV
TBIT
@REG1,AL
@REG2,#BIT_X
---------+
---------|-----+
+-----|---> Write
+---> Read
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6
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Peripheral Interrupt Expansion (PIE)
The peripheral interrupt expansion (PIE) block multiplexes numerous interrupt sources into a smaller set of
interrupt inputs. The PIE block can support 96 individual interrupts that are grouped into blocks of eight.
Each group is fed into one of 12 core interrupt lines (INT1 to INT12). Each of the 96 interrupts is
supported by its own vector stored in a dedicated RAM block that you can modify. The CPU, upon
servicing the interrupt, automatically fetches the appropriate interrupt vector. It takes nine CPU clock
cycles to fetch the vector and save critical CPU registers. Therefore, the CPU can respond quickly to
interrupt events. Prioritization of interrupts is controlled in hardware and software. Each individual interrupt
can be enabled/disabled within the PIE block.
6.1
Overview of the PIE Controller
The 28x CPU supports one nonmaskable interrupt (NMI) and 16 maskable prioritized interrupt requests
(INT1-INT14, RTOSINT, and DLOGINT) at the CPU level. The 28x devices have many peripherals and
each peripheral is capable of generating one or more interrupts in response to many events at the
peripheral level. Because the CPU does not have sufficient capacity to handle all peripheral interrupt
requests at the CPU level, a centralized peripheral interrupt expansion (PIE) controller is required to
arbitrate the interrupt requests from various sources such as peripherals and other external pins.
The PIE vector table is used to store the address (vector) of each interrupt service routine (ISR) within the
system. There is one vector per interrupt source including all MUXed and nonMUXed interrupts. You
populate the vector table during device initialization and you can update it during operation.
6.1.1
Interrupt Operation Sequence
Figure 76 shows an overview of the interrupt operation sequence for all multiplexed PIE interrupts.
Interrupt sources that are not multiplexed are fed directly to the CPU.
Figure 76. Overview: Multiplexing of Interrupts Using the PIE Block
IFR(12:1)
INTM
IER(12:1)
INT1
INT2
1
MUX
INT11
INT12
(Flag)
INTx
Global
Enable
(Enable)
INTx.1
INTx.2
INTx.3
INTx.4
INTx.5
INTx.6
INTx.7
INTx.8
MUX
PIEACKx
(Enable/Flag)
•
110
(Enable)
(Flag)
PIEIERx(8:1)
PIEIFRx(8:1)
CPU
0
From
Peripherals or
External
Interrupts
Peripheral Level
An interrupt-generating event occurs in a peripheral. The interrupt flag (IF) bit corresponding to that
event is set in a register for that particular peripheral.
If the corresponding interrupt enable (IE) bit is set, the peripheral generates an interrupt request to the
PIE controller. If the interrupt is not enabled at the peripheral level, then the IF remains set until
cleared by software. If the interrupt is enabled at a later time, and the interrupt flag is still set, the
interrupt request is asserted to the PIE.
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•
•
Interrupt flags within the peripheral registers must be manually cleared. See the peripheral reference
guide for a specific peripheral for more information.
PIE Level
The PIE block multiplexes eight peripheral and external pin interrupts into one CPU interrupt. These
interrupts are divided into 12 groups: PIE group 1 - PIE group 12. The interrupts within a group are
multiplexed into one CPU interrupt. For example, PIE group 1 is multiplexed into CPU interrupt 1
(INT1) while PIE group 12 is multiplexed into CPU interrupt 12 (INT12). Interrupt sources connected to
the remaining CPU interrupts are not multiplexed. For the nonmultiplexed interrupts, the PIE passes
the request directly to the CPU.
For multiplexed interrupt sources, each interrupt group in the PIE block has an associated flag register
(PIEIFRx) and enable (PIEIERx) register (x = PIE group 1 - PIE group 12). Each bit, referred to as y,
corresponds to one of the 8 MUXed interrupts within the group. Thus PIEIFRx.y and PIEIERx.y
correspond to interrupt y (y = 1-8) in PIE group x (x = 1-12). In addition, there is one acknowledge bit
(PIEACK) for every PIE interrupt group referred to as PIEACKx (x = 1-12). Figure 77 illustrates the
behavior of the PIE hardware under various PIEIFR and PIEIER register conditions.
Once the request is made to the PIE controller, the corresponding PIE interrupt flag (PIEIFRx.y) bit is
set. If the PIE interrupt enable (PIEIERx.y) bit is also set for the given interrupt then the PIE checks the
corresponding PIEACKx bit to determine if the CPU is ready for an interrupt from that group. If the
PIEACKx bit is clear for that group, then the PIE sends the interrupt request to the CPU. If PIEACKx is
set, then the PIE waits until it is cleared to send the request for INTx. See Section 6.3 for details.
CPU Level
Once the request is sent to the CPU, the CPU level interrupt flag (IFR) bit corresponding to INTx is set.
After a flag has been latched in the IFR, the corresponding interrupt is not serviced until it is
appropriately enabled in the CPU interrupt enable (IER) register or the debug interrupt enable register
(DBGIER) and the global interrupt mask (INTM) bit.
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Figure 77. Typical PIE/CPU Interrupt Response - INTx.y
Start
Stage A
PIEIFRx.y=1
?
Wait for any
PIEIFRx.y=1
Stage E
IFRx bit set 1
No
Stage F
IERx bit=1
?
Yes
Yes
Stage B
PIEIERx.y=1
?
Wait for
PIEIERx.y=1
No
Stage C
PIEACKx=0
?
Yes
Hardware sets
PIEACKx=1
Interrupts
to CPU
Stage G
INTM bit=0
?
No
Yes
Yes
Wait for
S/W to clear
PIEACKx bit=0
No
Stage D
Interrupt request
sent to 28x CPU
on INTx
No
Stage H
CPU responds
IFRx=0, IERx=0
INTM=1, EALLOW=0
Context Save performed
Stage I
Vector fetched from the PIE(A)
PIEIFRx.y is cleared
CPU branches to ISR
Stage J
Interrupt service routine responds
Write 1 to PIEACKx bit to clear
to enable other interrupts in
PIEIFRx group
Re-enable interrupts, INTM=0
Return
End
PIE interrupt control
A
CPU interrupt control
For multiplexed interrupts, the PIE responds with the highest priority interrupt that is both flagged and enabled. If
there is no interrupt both flagged and enabled, then the highest priority interrupt within the group (INTx.1 where x is
the PIE group) is used. See Section Section 6.3.3 for details.
As shown in Table 105, the requirements for enabling the maskable interrupt at the CPU level depends on
the interrupt handling process being used. In the standard process, which happens most of the time, the
DBGIER register is not used. When the 28x is in real-time emulation mode and the CPU is halted, a
different process is used. In this special case, the DBGIER is used and the INTM bit is ignored. If the
device is in real-time mode and the CPU is running, the standard interrupt-handling process applies.
Table 105. Enabling Interrupt
Interrupt Handling Process
Interrupt Enabled If…
Standard
INTM = 0 and bit in IER is 1
Device in real-time mode and halted
Bit in IER is 1 and DBGIER is 1
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The CPU then prepares to service the interrupt. This preparation process is described in detail in
TMS320x28x DSP CPU and Instruction Set Reference Guide (literature number SPRU430). In
preparation, the corresponding CPU IFR and IER bits are cleared, EALLOW and LOOP are cleared, INTM
and DBGM are set, the pipeline is flushed and the return address is stored, and the automatic context
save is performed. The vector of the ISR is then fetched from the PIE module. If the interrupt request
comes from a multiplexed interrupt, the PIE module uses the group PIEIERx and PIEIFRx registers to
decode which interrupt needs to be serviced. This decode process is described in detail in Section
Section 6.3.3.
The address for the interrupt service routine that is executed is fetched directly from the PIE interrupt
vector table. There is one 32-bit vector for each of the possible 96 interrupts within the PIE. Interrupt flags
within the PIE module (PIEIFRx.y) are automatically cleared when the interrupt vector is fetched. The PIE
acknowledge bit for a given interrupt group, however, must be cleared manually when ready to receive
more interrupts from the PIE group.
6.2
Vector Table Mapping
On 28xx devices, the interrupt vector table can be mapped to four distinct locations in memory. In practice
only the PIE vector table mapping is used.
This vector mapping is controlled by the following mode bits/signals:
VMAP:
M0M1MAP:
ENPIE:
VMAP is found in Status Register 1 ST1 (bit 3). A device reset sets this bit to 1. The state of this bit can
be modified by writing to ST1 or by SETC/CLRC VMAP instructions. For normal operation leave this bit
set.
M0M1MAP is found in Status Register 1 ST1 (bit 11). A device reset sets this bit to 1. The state of this bit
can be modified by writing to ST1 or by SETC/CLRC M0M1MAP instructions. For normal 28xx device
operation, this bit should remain set. M0M1MAP = 0 is reserved for TI testing only.
ENPIE is found in PIECTRL Register (bit 0). The default value of this bit, on reset, is set to 0 (PIE
disabled). The state of this bit can be modified after reset by writing to the PIECTRL register (address
0x0000 0CE0).
Using these bits and signals the possible vector table mappings are shown in Table 106.
Table 106. Interrupt Vector Table Mapping
(1)
Vector MAPS
Vectors Fetched From
Address Range
VMAP
M0M1MAP
ENPIE
M1 Vector (1)
M1 SARAM Block
0x000000 - 0x00003F
0
0
X
M0 Vector (1)
M0 SARAM Block
0x000000 - 0x00003F
0
1
X
BROM Vector
Boot ROM Block
0x3FFFC0 - 0x3FFFFF
1
X
0
PIE Vector
PIE Block
0x000D00 - 0x000DFF
1
X
1
Vector map M0 and M1 Vector is a reserved mode only. On the 28x devices these are used as SARAM.
The M1 and M0 vector table mapping are reserved for TI testing only. When using other vector mappings,
the M0 and M1 memory blocks are treated as SARAM blocks and can be used freely without any
restrictions.
After a device reset operation, the vector table is mapped as shown in Table 107.
Table 107. Vector Table Mapping After Reset Operation
ENPIE
Vector MAPS
BROM Vector
(1)
(2)
(2)
Reset Fetched From
Address Range
Boot ROM Block
0x3FFFC0 - 0x3FFFFF
VMAP
1
(1)
M0M1MAP
(1)
1
(1)
0
On the 28x devices, the VMAP and M0M1MAP modes are set to 1 on reset. The ENPIE mode is forced to 0 on reset.
The reset vector is always fetched from the boot ROM.
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After the reset and boot is complete, the PIE vector table should be initialized by the user's code. Then the
application enables the PIE vector table. From that point on the interrupt vectors are fetched from the PIE
vector table. Note: when a reset occurs, the reset vector is always fetched from the vector table as shown
in Table 107. After a reset the PIE vector table is always disabled.
Figure 78 illustrates the process by which the vector table mapping is selected.
Figure 78. Reset Flow Diagram
Used for test purposes only
Recommended flow for 280x applications
Reset
(power-on reset or warm reset)
PIE disabled (ENPIE=0)
VMAP = 1
OBJMODE = 0
AMODE = 0
MOM1MAP = 1
User code initializes:
OBJMODE and AMODE state1
CPU IER register and INTM
VMAP state
Yes
Reset vector fetched from
boot ROM
No
Using
peripheral
interrupts
?
Branch into bootloader
routines, depending on the
state of GPIO pins
No
VMAP = 1
?
Vectors
(except for reset)
are fetched
from M0 vector
map‡
Yes
User code initializes:
OBJMODE and AMODE state†
PIE enable (ENPIE = 1)
PIE vector table
PIEIERx registers
CPU IER register and INTM
Vectors
(except for reset) are
fetched from BROM
vector map‡
Vectors (except for reset)
are fetched from PIE vector map‡
A
The compatibility operating mode of the 28x CPU is determined by a combination of the OBJMODE and AMODE bits
in Status Register 1 (ST1):
Operating Mode
C28x Mode
24x/240xA Source-Compatible
C27x Object-Compatible
B
114
OBJMODE
1
1
0
AMODE
0
1
0
(Default at reset)
The reset vector is always fetched from the boot ROM.
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6.3
Interrupt Sources
Figure 79 shows how the various interrupt sources are multiplexed within the devices. This multiplexing
(MUX) scheme may not be exactly the same on all 28x devices. See the data manual of your particular
device for details.
Figure 79. PIE Interrupt Sources and External Interrupts XINT1/XINT2/XINT3
Peripherals
(SPI, SCI, EPWM,
HRPWM, ECAP, ADC)
WDINT
WAKEINT
Sync
Watchdog
LPMINT
Low Power Modes
XINT1
Interrupt Control
MUX
SYSCLKOUT
XINT1
C28
Core
XINT2CTR(15:0)
GPIOXINT1SEL(4:0)
ADC
XINT2
XINT2SOC
XINT2
Interrupt Control
XINT2CR(15:0)
XINT3CTR(15:0)
MUX
PIE
INT1
to
INT12
Up to 96 Interrupts
XINT1CR(15:0)
GPIOXINT2SEL(4:0)
XINT3
XINT3
Interrupt Control
MUX
GPIO0.int
XINT3CR(15:0)
GPIO
MUX
GPIO31.int
XINT3CTR(15:0)
GPIOXINT3SEL(4:0)
TINT0
CPU TIMER 0
INT13
TINT1
CPU TIMER 1
INT14
TINT2
CPU TIMER 2
NMI
NMI interrupt with watchdog function
(See the NMI watchdog section)
CPUTMR2CLK
CLOCKFAIL
NMIRS
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Procedure for Handling Multiplexed Interrupts
The PIE module multiplexes eight peripheral and external pin interrupts into one CPU interrupt. These
interrupts are divided into 12 groups: PIE group 1 - PIE group 12. Each group has an associated enable
PIEIER and flag PIEIFR register. These registers are used to control the flow of interrupts to the CPU. The
PIE module also uses the PIEIER and PIEIFR registers to decode to which interrupt service routine the
CPU should branch.
There are three main rules that should be followed when clearing bits within the PIEIFR and the PIEIER
registers:
Rule 1: Never clear a PIEIFR bit by software
An incoming interrupt may be lost while a write or a read-modify-write operation to the PIEIFR register
takes place. To clear a PIEIFR bit, the pending interrupt must be serviced. If you want to clear the PIEIFR
bit without executing the normal service routine, then use the following procedure:
1. Set the EALLOW bit to allow modification to the PIE vector table.
2. Modify the PIE vector table so that the vector for the peripheral's service routine points to a temporary
ISR. This temporary ISR will only perform a return from interrupt (IRET) operation.
3. Enable the interrupt so that the interrupt will be serviced by the temporary ISR.
4. After the temporary interrupt routine is serviced, the PIEIFR bit will be clear
5. Modify the PIE vector table to re-map the peripheral's service routine to the proper service routine.
6. Clear the EALLOW bit.
Rule 2: Procedure for software-prioritizing interrupts
Use the method found in the C2833x C/C++ Header Files and Peripheral Examples in C (literature
number SPRC530).
(a) Use the CPU IER register as a global priority and the individual PIEIER registers for group priorities. In
this case the PIEIER register is only modified within an interrupt. In addition, only the PIEIER for the
same group as the interrupt being serviced is modified. This modification is done while the PIEACK bit
holds additional interrupts back from the CPU.
(b) Never disable a PIEIER bit for a group when servicing an interrupt from an unrelated group.
Rule 3: Disabling interrupts using PIEIER
If the PIEIER registers are used to enable and then later disable an interrupt then the procedure described
in Section 6.3.2 must be followed.
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6.3.2
Procedures for Enabling And Disabling Multiplexed Peripheral Interrupts
The proper procedure for enabling or disabling an interrupt is by using the peripheral interrupt
enable/disable flags. The primary purpose of the PIEIER and CPU IER registers is for software
prioritization of interrupts within the same PIE interrupt group. The software package C280x C/C++
Header Files and Peripheral Examples in C (literature number SPRC191) includes an example that
illustrates this method of software prioritizing interrupts.
Should bits within the PIEIER registers need to be cleared outside of this context, one of the following two
procedures should be followed. The first method preserves the associated PIE flag register so that
interrupts are not lost. The second method clears the associated PIE flag register.
Method 1: Use the PIEIERx register to disable the interrupt and preserve the associated PIEIFRx
flags.
To clear bits within a PIEIERx register while preserving the associated flags in the PIEIFRx register, the
following procedure should be followed:
Step a.
Step b.
Step c.
Step d.
Step e.
Step f.
Disable global interrupts (INTM = 1).
Clear the PIEIERx.y bit to disable the interrupt for a given peripheral. This can be done for
one or more peripherals within the same group.
Wait 5 cycles. This delay is required to be sure that any interrupt that was incoming to the
CPU has been flagged within the CPU IFR register.
Clear the CPU IFRx bit for the peripheral group. This is a safe operation on the CPU IFR
register.
Clear the PIEACKx bit for the peripheral group.
Enable global interrupts (INTM = 0).
Method 2: Use the PIEIERx register to disable the interrupt and clear the associated PIEIFRx flags.
To perform a software reset of a peripheral interrupt and clear the associated flag in the PIEIFRx register
and CPU IFR register, the following procedure should be followed:
Step 1.
Step 2.
Step 3.
Step 4.
Step 5.
Step 6.
Step 7.
Step 8.
Step 9.
Step 10.
Step 11.
Step 12.
Step 13.
Disable global interrupts (INTM = 1).
Set the EALLOW bit.
Modify the PIE vector table to temporarily map the vector of the specific peripheral interrupt to
a empty interrupt service routine (ISR). This empty ISR will only perform a return from
interrupt (IRET) instruction. This is the safe way to clear a single PIEIFRx.y bit without losing
any interrupts from other peripherals within the group.
Disable the peripheral interrupt at the peripheral register.
Enable global interrupts (INTM = 0).
Wait for any pending interrupt from the peripheral to be serviced by the empty ISR routine.
Disable global interrupts (INTM = 1).
Modify the PIE vector table to map the peripheral vector back to its original ISR.
Clear the EALLOW bit.
Disable the PIEIER bit for given peripheral.
Clear the IFR bit for given peripheral group (this is safe operation on CPU IFR register).
Clear the PIEACK bit for the PIE group.
Enable global interrupts.
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Flow of a Multiplexed Interrupt Request From a Peripheral to the CPU
Figure 80 shows the flow with the steps shown in circled numbers. Following the diagram, the steps are
described.
Figure 80. Multiplexed Interrupt Request Flow Diagram
3a
2
1
PIE
interrupt
flag
Peripheral
IE/IF
PIE
interrupt
enable
Highest
PIEIERx.1
0
PIEIFRx.1
latch
0
Vector
1
3b
PIE group
acknowledge
4
PIEACKx
5
1
1
Search order
highest to
lowest
8 interrupts
per group
0
Pulse
gen
1=valid Int
IFRx
latch
6
7
IERx
INTM
8
0
1
CPU
0
1
CPU
interrupt
logic
Lowest
Peripheral
IE/IF
PIEIERx.8
0
PIEIFRx.8
latch
0
Vector
Step 1.
Step 2.
Step 3.
Step 4.
Step 5.
Step 6.
Step 7.
Step 8.
Step 9.
118
System Control
1
Vector is fetched
only after CPU
interrupt logic
has recognized
the interrupt
1
9
Any peripheral or external interrupt within the PIE group generates an interrupt. If interrupts
are enabled within the peripheral module then the interrupt request is sent to the PIE module.
The PIE module recognizes that interrupt y within PIE group x (INTx.y) has asserted an
interrupt and the appropriate PIE interrupt flag bit is latched: PIEIFRx.y = 1.
For the interrupt request to be sent from the PIE to the CPU, both of the following conditions
must be true:
(a) The proper enable bit must be set (PIEIERx.y = 1) and
(b) The PIEACKx bit for the group must be clear.
If both conditions in 3a and 3b are true, then an interrupt request is sent to the CPU and the
acknowledge bit is again set (PIEACKx = 1). The PIEACKx bit will remain set until you clear it
to indicate that additional interrupts from the group can be sent from the PIE to the CPU.
The CPU interrupt flag bit is set (CPU IFRx = 1) to indicate a pending interrupt x at the CPU
level.
If the CPU interrupt is enabled (CPU IER bit x = 1, or DBGIER bit x = 1) AND the global
interrupt mask is clear (INTM = 0) then the CPU will service the INTx.
The CPU recognizes the interrupt and performs the automatic context save, clears the IER
bit, sets INTM, and clears EALLOW. All of the steps that the CPU takes in order to prepare to
service the interrupt are documented in the TM S320C28x DSP CPU and Instruction Set
Reference Guide (literature number SPRU430).
The CPU will then request the appropriate vector from the PIE.
For multiplexed interrupts, the PIE module uses the current value in the PIEIERx and
PIEIFRx registers to decode which vector address should be used. There are two possible
cases:
(a) The vector for the highest priority interrupt within the group that is both enabled in the
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PIEIERx register, and flagged as pending in the PIEIFRx is fetched and used as the
branch address. In this manner if an even higher priority enabled interrupt was flagged
after Step 7, it will be serviced first.
(b) If no flagged interrupts within the group are enabled, then the PIE will respond with the
vector for the highest priority interrupt within that group. That is the branch address used
for INTx.1. This behavior corresponds to the 28x TRAP or INT instructions.
NOTE: Because the PIEIERx register is used to determine which vector will be used for the branch,
you must take care when clearing bits within the PIEIERx register. The proper procedure for
clearing bits within a PIEIERx register is described in Section 6.3.2. Failure to follow these
steps can result in changes occurring to the PIEIERx register after an interrupt has been
passed to the CPU at Step 5 in Figure 6-5. In this case, the PIE will respond as if a TRAP or
INT instruction was executed unless there are other interrupts both pending and enabled.
At this point, the PIEIFRx.y bit is cleared and the CPU branches to the vector of the interrupt fetched
from the PIE.
6.3.4
The PIE Vector Table
The PIE vector table (see Table 109) consists of a 256 x 16 SARAM block that can also be used as RAM
(in data space only) if the PIE block is not in use. The PIE vector table contents are undefined on reset.
The CPU fixes interrupt priority for INT1 to INT12. The PIE controls priority for each group of eight
interrupts. For example, if INT1.1 should occur simultaneously with INT8.1, both interrupts are presented
to the CPU simultaneously by the PIE block, and the CPU services INT1.1 first. If INT1.1 should occur
simultaneously with INT1.8, then INT1.1 is sent to the CPU first and then INT1.8 follows. Interrupt
prioritization is performed during the vector fetch portion of the interrupt processing.
When the PIE is enabled, a TRAP #1 through TRAP #12 or an INTR INT1 to INTR INT12 instruction
transfers program control to the interrupt service routine corresponding to the first vector within the PIE
group. For example: TRAP #1 fetches the vector from INT1.1, TRAP #2 fetches the vector from INT2.1
and so forth. Similarly an OR IFR, #16-bit operation causes the vector to be fetched from INTR1.1 to
INTR12.1 locations, if the respective interrupt flag is set. All other TRAP, INTR, OR IFR,#16-bit operations
fetch the vector from the respective table location. The vector table is EALLOW protected.
Out of the 96 possible MUXed interrupts in Table 108, 43 interrupts are currently used. The remaining
interrupts are reserved for future devices. These reserved interrupts can be used as software interrupts if
they are enabled at the PIEIFRx level, provided none of the interrupts within the group is being used by a
peripheral. Otherwise, interrupts coming from peripherals may be lost by accidentally clearing their flags
when modifying the PIEIFR.
To summarize, there are two safe cases when the reserved interrupts can be used as software interrupts:
1. No peripheral within the group is asserting interrupts.
2. No peripheral interrupts are assigned to the group. For example, PIE group 11 and 12 do not have any
peripherals attached to them.
The interrupt grouping for peripherals and external interrupts connected to the PIE module is shown in
Table 108. Each row in the table shows the 8 interrupts multiplexed into a particular CPU interrupt. The
entire PIE vector table, including both MUXed and non-MUXed interrupts, is shown in Table 109.
Table 108. PIE MUXed Peripheral Interrupt Vector Table
INT1.y
INT2.y
INT3.y
INTx.8
INTx.7
INTx.6
INTx.5
INTx.4
INTx.3
INTx.2
INTx.1
WAKEINT
TINT0
ADCINT9
XINT2
XINT1
Reserved
ADCINT2
ADCINT1
(LPM/WD)
(TIMER 0)
(ADC)
Ext. int. 2
Ext. int. 1
-
(ADC)
(ADC)
0xD4E
0xD4C
0xD4A
0xD48
0xD46
0xD44
0xD42
0xD40
Reserved
Reserved
Reserved
Reserved
EPWM4_TZINT
EPWM3_TZINT
EPWM2_TZINT
EPWM1_TZINT
-
-
-
-
(ePWM4)
(ePWM3)
(ePWM2)
(ePWM1)
0xD5E
0xD5C
0xD5A
0xD58
0xD56
0xD54
0xD52
0xD50
Reserved
Reserved
Reserved
Reserved
EPWM4_INT
EPWM3_INT
EPWM2_INT
EPWM1_INT
-
-
-
-
(ePWM4)
(ePWM3)
(ePWM2)
(ePWM1)
0xD6E
0xD6C
0xD6A
0xD68
0xD66
0xD64
0xD62
0xD60
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Table 108. PIE MUXed Peripheral Interrupt Vector Table (continued)
INT4.y
INT5.y
INT6.y
INT7.y
INT8.y
INT9.y
INT10.y
INT11.y
INT12.y
INTx.8
INTx.7
INTx.6
INTx.5
INTx.4
INTx.3
INTx.2
INTx.1
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
ECAP1_INT
(eCAP1)
-
-
-
-
-
-
-
0xD7E
0xD7C
0xD7A
0xD78
0xD76
0xD74
0xD72
0xD70
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
-
-
-
-
-
-
-
-
0xD8E
0xD8C
0xD8A
0xD88
0xD86
0xD84
0xD82
0xD80
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
SPITXINTA
SPIRXINTA
-
-
-
-
-
-
(SPI-A)
(SPI-A)
0xD9E
0xD9C
0xD9A
0xD98
0xD96
0xD94
0xD92
0xD90
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
-
-
-
-
-
-
-
-
0xDAE
0xDAC
0xDAA
0xDA8
0xDA6
0xDA4
0xDA2
0xDA0
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
I2CINT2A
I2CINT1A
-
-
-
-
-
-
(I2C-A)
(I2C-A)
0xDBE
0xDBC
0xDBA
0xDB8
0xDB6
0xDB4
0xDB2
0xDB0
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
SCITXINTA
SCIRXINTA
(SCI-A)
-
-
-
-
-
-
(SCI-A)
0xDCE
0xDCC
0xDCA
0xDC8
0xDC6
0xDC4
0xDC2
0xDC0
ADCINT8
ADCINT7
ADCINT6
ADCINT5
ADCINT4
ADCINT3
ADCINT2
ADCINT1
(ADC)
(ADC)
(ADC)
(ADC)
(ADC)
(ADC)
(ADC)
(ADC)
0xDDE
0xDDC
0xDDA
0xDD8
0xDD6
0xDD4
0xDD2
0xDD0
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
-
-
-
-
-
-
-
-
0xDEE
0xDEC
0xDEA
0xDE8
0xDE6
0xDE4
0xDE2
0xDE0
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
XINT3
-
-
-
-
-
-
-
Ext. Int. 3
0xDFE
0xDFC
0xDFA
0xDF8
0xDF6
0xDF4
0xDF2
0xDF0
Table 109. PIE Vector Table
Name
VECTOR
ID
CPU
Priority
PIE Group
Priority
Reset
0
0x0000 0D00
2
Reset is always fetched from location
0x003F FFC0 in Boot ROM.
1
(highest)
-
INT1
1
0x0000 0D02
2
INT2
2
0x0000 0D04
2
Not used. See PIE Group 1
5
-
Not used. See PIE Group 2
6
INT3
3
0x0000 0D06
-
2
Not used. See PIE Group 3
7
-
INT4
4
INT5
5
0x0000 0D08
2
Not used. See PIE Group 4
8
-
0x0000 0D0A
2
Not used. See PIE Group 5
9
INT6
6
-
0x0000 0D0C
2
Not used. See PIE Group 6
10
INT7
-
7
0x0000 0D0E
2
Not used. See PIE Group 7
11
-
INT8
8
0x0000 0D10
2
Not used. See PIE Group 8
12
-
INT9
9
0x0000 0D12
2
Not used. See PIE Group 9
13
-
INT10
10
0x0000 0D14
2
Not used. See PIE Group 10
14
-
INT11
11
0x0000 0D16
2
Not used. See PIE Group 11
15
-
INT12
12
0x0000 0D18
2
Not used. See PIE Group 12
16
-
INT13
13
0x0000 0D1A
2
External Interrupt 13 (XINT13) or
CPU-Timer1
17
-
INT14
14
0x0000 0D1C
2
CPU-Timer2
(for TI/RTOS use)
18
-
DATALOG
15
0x0000 0D1E
2
CPU Data Logging Interrupt
19 (lowest)
-
(1)
(2)
Address
(1)
Size (x16) Description
(2)
Reset is always fetched from location 0x003F FFC0 in Boot ROM.
All the locations within the PIE vector table are EALLOW protected.
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Table 109. PIE Vector Table (continued)
Name
VECTOR
ID
Address
(1)
Size (x16) Description
(2)
CPU
Priority
PIE Group
Priority
RTOSINT
16
0x0000 0D20
2
CPU Real-Time OS Interrupt
4
-
EMUINT
17
0x0000 0D22
2
CPU Emulation Interrupt
2
-
NMI
18
0x0000 0D24
2
External Non-Maskable Interrupt
3
-
ILLEGAL
19
0x0000 0D26
2
Illegal Operation
-
-
USER1
20
0x0000 0D28
2
User-Defined Trap
-
-
USER2
21
0x0000 0D2A
2
User Defined Trap
-
-
USER3
22
0x0000 0D2C
2
User Defined Trap
-
-
USER4
23
0x0000 0D2E
2
User Defined Trap
-
-
USER5
24
0x0000 0D30
2
User Defined Trap
-
-
USER6
25
0x0000 0D32
2
User Defined Trap
-
-
USER7
26
0x0000 0D34
2
User Defined Trap
-
-
USER8
27
0x0000 0D36
2
User Defined Trap
-
-
USER9
28
0x0000 0D38
2
User Defined Trap
-
-
USER10
29
0x0000 0D3A
2
User Defined Trap
-
-
USER11
30
0x0000 0D3C
2
User Defined Trap
-
-
USER12
31
0x0000 0D3E
2
User Defined Trap
-
-
PIE Group 1 Vectors - MUXed into CPU INT1
INT1.1
32
0x0000 0D40
2
ADCINT1
(ADC)
5
1 (highest)
INT1.2
33
0x0000 0D42
2
ADCINT2
(ADC)
5
2
INT1.3
34
0x0000 0D44
2
Reserved
5
3
INT1.4
35
0x0000 0D46
2
XINT1
5
4
INT1.5
36
0x0000 0D48
2
XINT2
5
5
INT1.6
37
0x0000 0D4A
2
ADCINT9
(ADC)
5
6
INT1.7
38
0x0000 0D4C
2
TINT0
(CPUTimer0)
5
7
INT1.8
39
0x0000 0D4E
2
WAKEINT
(LPM/WD)
5
8 (lowest)
PIE Group 2 Vectors - MUXed into CPU INT2
INT2.1
40
0x0000 0D50
2
EPWM1_TZINT
(EPWM1)
6
1 (highest)
INT2.2
41
0x0000 0D52
2
EPWM2_TZINT
(EPWM2)
6
2
INT2.3
42
0x0000 0D54
2
EPWM3_TZINT
(EPWM3)
6
3
INT2.4
43
0x0000 0D56
2
EPWM4_TZINT
(EPWM4)
6
4
INT2.5
44
0x0000 0D58
2
Reserved
6
5
INT2.6
45
0x0000 0D5A
2
Reserved
6
6
INT2.7
46
0x0000 0D5C
2
Reserved
6
7
INT2.8
47
0x0000 0D5E
2
Reserved
6
8 (lowest)
PIE Group 3 Vectors - MUXed into CPU INT3
INT3.1
48
0x0000 0D60
2
EPWM1_INT
(EPWM1)
7
1 (highest)
INT3.2
49
0x0000 0D62
2
EPWM2_INT
(EPWM2)
7
2
INT3.3
50
0x0000 0D64
2
EPWM3_INT
(EPWM3)
7
3
INT3.4
51
0x0000 0D66
2
EPWM4_INT
(EPWM4)
7
4
INT3.5
52
0x0000 0D68
2
Reserved
7
5
INT3.6
53
0x0000 0D6A
2
Reserved
7
6
INT3.7
54
0x0000 0D6C
2
Reserved
7
7
INT3.8
55
0x0000 0D6E
2
Reserved
-
7
8 (lowest)
PIE Group 4 Vectors - MUXed into CPU INT4
INT4.1
56
0x0000 0D70
2
ECAP1_INT
(ECAP1)
8
1 (highest)
INT4.2
57
0x0000 0D72
2
Reserved
-
8
2
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Table 109. PIE Vector Table (continued)
Name
VECTOR
ID
CPU
Priority
PIE Group
Priority
INT4.3
58
0x0000 0D74
2
Reserved
INT4.4
59
0x0000 0D76
2
Reserved
-
8
3
-
8
INT4.5
60
0x0000 0D78
2
4
Reserved
-
8
INT4.6
61
0x0000 0D7A
5
2
Reserved
-
8
6
INT4.7
62
INT4.8
63
0x0000 0D7C
2
Reserved
-
8
7
0x0000 0D7E
2
Reserved
-
8
8 (lowest)
Address
(1)
Size (x16) Description
(2)
PIE Group 5 Vectors - MUXed into CPU INT5
INT5.1
64
0x0000 0D80
2
EQEP1_INT
(EQEP1)
9
1 (highest)
INT5.2
65
0x0000 0D82
2
Reserved
(EQEP2)
9
2
INT5.3
66
0x0000 0D84
2
Reserved
9
3
INT5.4
67
0x0000 0D86
2
Reserved
-
9
4
INT5.5
68
0x0000 0D88
2
Reserved
-
9
5
INT5.6
69
0x0000 0D8A
2
Reserved
-
9
6
INT5.7
70
0x0000 0D8C
2
Reserved
-
9
7
INT5.8
71
0x0000 0D8E
2
Reserved
-
9
8 (lowest)
PIE Group 6 Vectors - MUXed into CPU INT6
INT6.1
72
0x0000 0D90
2
SPIRXINTA
(SPI-A)
10
1 (highest)
INT6.2
73
0x0000 0D92
2
SPITXINTA
(SPI-A)
10
2
INT6.3
74
0x0000 0D94
2
Reserved
10
3
INT6.4
75
0x0000 0D96
2
Reserved
10
4
INT6.5
76
0x0000 0D98
2
Reserved
10
5
INT6.6
77
0x0000 0D9A
2
Reserved
10
6
INT6.7
78
0x0000 0D9C
2
Reserved
10
7
INT6.8
79
0x0000 0D9E
2
Reserved
10
8 (lowest)
PIE Group 7 Vectors - MUXed into CPU INT7
INT7.1
80
0x0000 0DA0
2
Reserved
-
11
1 (highest)
INT7.2
81
0x0000 0DA2
2
Reserved
-
11
2
INT7.3
82
0x0000 0DA4
2
Reserved
-
11
3
INT7.4
83
0x0000 0DA6
2
Reserved
-
11
4
INT7.5
84
0x0000 0DA8
2
Reserved
-
11
5
INT7.6
85
0x0000 0DAA
2
Reserved
-
11
6
INT7.7
86
0x0000 0DAC
2
Reserved
-
11
7
INT7.8
87
0x0000 0DAE
2
Reserved
-
11
8 (lowest)
PIE Group 8 Vectors - MUXed into CPU INT8
INT8.1
88
0x0000 0DB0
2
I2CINT1A
(I2C-A)
12
1 (highest)
INT8.2
89
0x0000 0DB2
2
I2CINT2A
(I2C-A)
12
2
INT8.3
90
0x0000 0DB4
2
Reserved
-
12
3
INT8.4
91
0x0000 0DB6
2
Reserved
-
12
4
INT8.5
92
0x0000 0DB8
2
Reserved
-
12
5
INT8.6
93
0x0000 0DBA
2
Reserved
-
12
6
INT8.7
94
0x0000 0DBC
2
Reserved
-
12
7
INT8.8
95
0x0000 0DBE
2
Reserved
-
12
8 (lowest)
PIE Group 9 Vectors - MUXed into CPU INT9
INT9.1
96
0x0000 0DC0
2
SCIRXINTA
(SCI-A)
13
1 (highest)
INT9.2
97
0x0000 0DC2
2
SCITXINTA
(SCI-A)
13
2
INT9.3
98
0x0000 0DC4
2
Reserved
13
3
INT9.4
99
0x0000 0DC6
2
Reserved
13
4
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Table 109. PIE Vector Table (continued)
Name
VECTOR
ID
INT9.5
100
0x0000 0DC8
2
INT9.6
101
0x0000 0DCA
2
INT9.7
102
0x0000 0DCC
2
Reserved
-
13
7
INT9.8
103
0x0000 0DCE
2
Reserved
-
13
8 (lowest)
Address
(1)
CPU
Priority
PIE Group
Priority
Reserved
13
5
Reserved
13
6
Size (x16) Description
(2)
PIE Group 10 Vectors - MUXed into CPU INT10
INT10.1
104
0x0000 0DD0
2
ADCINT1
(ADC)
14
1 (highest)
INT10.2
105
0x0000 0DD2
2
ADCINT2
(ADC)
14
2
INT10.3
106
0x0000 0DD4
2
ADCINT3
(ADC)
14
3
INT10.4
107
0x0000 0DD6
2
ADCINT4
(ADC)
14
4
INT10.5
108
0x0000 0DD8
2
ADCINT5
(ADC)
14
5
INT10.6
109
0x0000 0DDA
2
ADCINT6
(ADC)
14
6
INT10.7
110
0x0000 0DDC
2
ADCINT7
(ADC)
14
7
INT10.8
111
0x0000 0DDE
2
ADCINT8
(ADC)
14
8 (lowest)
PIE Group 11 Vectors - MUXed into CPU INT11
INT11.1
112
0x0000 0DE0
2
Reserved
-
15
1 (highest)
INT11.2
113
0x0000 0DE2
2
Reserved
-
15
2
INT11.3
114
0x0000 0DE4
2
Reserved
-
15
3
INT11.4
115
0x0000 0DE6
2
Reserved
-
15
4
INT11.5
116
0x0000 0DE8
2
Reserved
-
15
5
INT11.6
117
0x0000 0DEA
2
Reserved
-
15
6
INT11.7
118
0x0000 0DEC
2
Reserved
-
15
7
INT11.8
119
0x0000 0DEE
2
Reserved
-
15
8 (lowest)
PIE Group 12 Vectors - Muxed into CPU INT12
INT12.1
120
0x0000 0DF0
2
XINT3
-
16
1 (highest)
INT12.2
121
0x0000 0DF2
2
Reserved
-
16
2
INT12.3
122
0x0000 0DF4
2
Reserved
-
16
3
INT12.4
123
0x0000 0DF6
2
Reserved
-
16
4
INT12.5
124
0x0000 0DF8
2
Reserved
-
16
5
INT12.6
125
0x0000 0DFA
2
Reserved
-
16
6
INT12.7
126
0x0000 0DFC
2
Reserved
-
16
7
INT12.8
127
0x0000 0DFE
2
Reserved
-
16
8 (lowest)
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6.4
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PIE Configuration Registers
The registers controlling the functionality of the PIE block are shown in Table 110.
Table 110. PIE Configuration and Control Registers
124
Name
Address
PIECTRL
0x0000 - 0CE0
1
PIE, Control Register
PIEACK
0x0000 - 0CE1
1
PIE, Acknowledge Register
PIEIER1
0x0000 - 0CE2
1
PIE, INT1 Group Enable Register
PIEIFR1
0x0000 - 0CE3
1
PIE, INT1 Group Flag Register
PIEIER2
0x0000 - 0CE4
1
PIE, INT2 Group Enable Register
PIEIFR2
0x0000 - 0CE5
1
PIE, INT2 Group Flag Register
PIEIER3
0x0000 - 0CE6
1
PIE, INT3 Group Enable Register
PIEIFR3
0x0000 - 0CE7
1
PIE, INT3 Group Flag Register
PIEIER4
0x0000 - 0CE8
1
PIE, INT4 Group Enable Register
PIEIFR4
0x0000 - 0CE9
1
PIE, INT4 Group Flag Register
PIEIER5
0x0000 - 0CEA
1
PIE, INT5 Group Enable Register
PIEIFR5
0x0000 - 0CEB
1
PIE, INT5 Group Flag Register
PIEIER6
0x0000 - 0CEC
1
PIE, INT6 Group Enable Register
PIEIFR6
0x0000 - 0CED
1
PIE, INT6 Group Flag Register
PIEIER7
0x0000 - 0CEE
1
PIE, INT7 Group Enable Register
PIEIFR7
0x0000 - 0CEF
1
PIE, INT7 Group Flag Register
PIEIER8
0x0000 - 0CF0
1
PIE, INT8 Group Enable Register
PIEIFR8
0x0000 - 0CF1
1
PIE, INT8 Group Flag Register
PIEIER9
0x0000 - 0CF2
1
PIE, INT9 Group Enable Register
PIEIFR9
0x0000 - 0CF3
1
PIE, INT9 Group Flag Register
PIEIER10
0x0000 - 0CF4
1
PIE, INT10 Group Enable Register
PIEIFR10
0x0000 - 0CF5
1
PIE, INT10 Group Flag Register
PIEIER11
0x0000 - 0CF6
1
PIE, INT11 Group Enable Register
PIEIFR11
0x0000 - 0CF7
1
PIE, INT11 Group Flag Register
PIEIER12
0x0000 - 0CF8
1
PIE, INT12 Group Enable Register
PIEIFR12
0x0000 - 0CF9
1
PIE, INT12 Group Flag Register
System Control
Size (x16)
Description
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6.5
PIE Interrupt Registers
Figure 81. PIECTRL Register (Address 0xCE0)
15
1
0
PIEVECT
ENPIE
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 111. PIECTRL Register Address Field Descriptions
Bits
Field
15-1
PIEVECT
Value
Description
These bits indicate the address within the PIE vector table from which the vector was fetched. The
least significant bit of the address is ignored and only bits 1 to 15 of the address is shown. You can
read the vector value to determine which interrupt generated the vector fetch.
For Example: If PIECTRL = 0x0D27 then the vector from address 0x0D26 (illegal operation) was
fetched.
0
ENPIE
Enable vector fetching from PIE vector table.
Note: The reset vector is never fetched from the PIE, even when it is enabled. This vector is always
fetched from boot ROM.
0
If this bit is set to 0, the PIE block is disabled and vectors are fetched from the CPU vector table in
boot ROM. All PIE block registers (PIEACK, PIEIFR, PIEIER) can be accessed even when the PIE
block is disabled.
1
When ENPIE is set to 1, all vectors, except for reset, are fetched from the PIE vector table. The reset
vector is always fetched from the boot ROM.
Figure 82. PIE Interrupt Acknowledge Register (PIEACK) Register (Address 0xCE1)
15
12
11
0
Reserved
PIEACK
R-0
R/W1C-0
LEGEND: R/W1C = Read/Write 1 to clear; R = Read only; -n = value after reset
Table 112. PIE Interrupt Acknowledge Register (PIEACK) Field Descriptions
Bits
Field
Value
Description
15-12 Reserved
Reserved
11-0
Each bit in PIEACK refers to a specific PIE group. Bit 0 refers to interrupts in PIE group 1 that are
MUXed into INT1 up to Bit 11, which refers to PIE group 12 which is MUXed into CPU IN T12
PIEACK
bit x = 0
(1)
If a bit reads as a 0, it indicates that the PIE can send an interrupt from the respective group to the
CPU.
Writes of 0 are ignored.
bit x = 1
Reading a 1 indicates if an interrupt from the respective group has been sent to the CPU and all
other interrupts from the group are currently blocked.
Writing a 1 to the respective interrupt bit clears the bit and enables the PIE block to drive a pulse into
the CPU interrupt input if an interrupt is pending for that group.
(1)
bit x = PIEACK bit 0 - PIEACK bit 11. Bit 0 refers to CPU INT1 up to Bit 11, which refers to CPU INT12
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PIE Interrupt Flag Registers
There are twelve PIEIFR registers, one for each CPU interrupt used by the PIE module (INT1-INT12).
Figure 83. PIEIFRx Register (x = 1 to 12)
15
8
Reserved
R-0
7
6
5
4
3
2
1
0
INTx.8
INTx.7
INTx.6
INTx.5
INTx.4
INTx.3
INTx.2
INTx.1
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 113. PIEIFRx Register Field Descriptions
Bits
Field
Description
15-8
Reserved
Reserved
7
INTx.8
6
INTx.7
5
INTx.6
These register bits indicate whether an interrupt is currently active. They behave very much like the CPU
interrupt flag register. When an interrupt is active, the respective register bit is set. The bit is cleared when the
interrupt is serviced or by writing a 0 to the register bit. This register can also be read to determine which
interrupts are active or pending. x = 1 to 12. INTx means CPU INT1 to INT12
4
INTx.5
The PIEIFR register bit is cleared during the interrupt vector fetch portion of the interrupt processing.
3
INTx.4
Hardware has priority over CPU accesses to the PIEIFR registers.
2
INTx.3
1
INTx.2
0
INTx.1
NOTE: Never clear a PIEIFR bit. An interrupt may be lost during the read-modify-write operation.
See Section Section 6.3.1 for a method to clear flagged interrupts.
6.5.2
PIE Interrupt Enable Registers
There are twelve PIEIER registers, one for each CPU interrupt used by the PIE module (INT1-INT12).
Figure 84. PIEIERx Register (x = 1 to 12)
15
8
Reserved
R-0
7
6
5
4
3
2
1
0
INTx.8
INTx.7
INTx.6
INTx.5
INTx.4
INTx.3
INTx.2
INTx.1
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
126
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Table 114. PIEIERx Register (x = 1 to 12) Field Descriptions
Bits
Field
Description
15-8
Reserved
Any writes to these (bits) must always have a value of 0.
7
INTx.8
6
INTx.7
These register bits individually enable an interrupt within a group and behave very much like the core interrupt
enable register. Setting a bit to 1 enables the servicing of the respective interrupt. Setting a bit to 0 disables
the servicing of the interrupt. x = 1 to 12. INTx means CPU INT1 to INT12
5
INTx.6
4
INTx.5
3
INTx.4
2
INTx.3
1
INTx.2
0
INTx.1
NOTE: Take care when clearing PIEIER bits during normal operation. See Section Section 6.3.2 for
the proper procedure for handling these bits.
6.5.3
CPU Interrupt Flag Register (IFR)
The CPU interrupt flag register (IFR), is a 16-bit, CPU register and is used to identify and clear pending
interrupts. The IFR contains flag bits for all the maskable interrupts at the CPU level (INT1-INT14,
DLOGINT and RTOSINT). When the PIE is enabled, the PIE module multiplexes interrupt sources for
INT1-INT12.
When a maskable interrupt is requested, the flag bit in the corresponding peripheral control register is set
to 1. If the corresponding mask bit is also 1, the interrupt request is sent to the CPU, setting the
corresponding flag in the IFR. This indicates that the interrupt is pending or waiting for acknowledgment.
To identify pending interrupts, use the PUSH IFR instruction and then test the value on the stack. Use the
OR IFR instruction to set IFR bits and use the AND IFR instruction to manually clear pending interrupts.
All pending interrupts are cleared with the AND IFR #0 instruction or by a hardware reset.
The following events also clear an IFR flag:
• The CPU acknowledges the interrupt.
• The 28x device is reset.
NOTE:
1.
2.
3.
4.
To clear a CPU IFR bit, you must write a zero to it, not a one.
When a maskable interrupt is acknowledged, only the IFR bit is cleared automatically.
The flag bit in the corresponding peripheral control register is not cleared. If an
application requires that the control register flag be cleared, the bit must be cleared by
software.
When an interrupt is requested by an INTR instruction and the corresponding IFR bit is
set, the CPU does not clear the bit automatically. If an application requires that the IFR
bit be cleared, the bit must be cleared by software.
IMR and IFR registers pertain to core-level interrupts. All peripherals have their own
interrupt mask and flag bits in their respective control/configuration registers. Note that
several peripheral interrupts are grouped under one core-level interrupt.
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Figure 85. Interrupt Flag Register (IFR) — CPU Register
15
14
13
12
11
10
9
8
RTOSINT
DLOGINT
INT14
INT13
INT12
INT11
INT10
INT9
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
7
6
5
4
3
2
1
0
INT8
INT7
INT6
INT5
INT4
INT3
INT2
INT1
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 115. Interrupt Flag Register (IFR) — CPU Register Field Descriptions
Bits
15
14
13
12
11
10
9
8
7
6
128
Field
Value
RTOSINT
Real-time operating system flag. RTOSINT is the flag for RTOS interrupts.
0
No RTOS interrupt is pending
1
At least one RTOS interrupt is pending. Write a 0 to this bit to clear it to 0 and clear the interrupt
request
DLOGINT
Data logging interrupt fag. DLOGINT is the flag for data logging interrupts.
0
No DLOGINT is pending
1
At least one DLOGINT interrupt is pending. Write a 0 to this bit to clear it to 0 and clear the interrupt
request
INT14
Interrupt 14 flag. INT14 is the flag for interrupts connected to CPU interrupt level INT14.
0
No INT14 interrupt is pending
1
At least one INT14 interrupt is pending. Write a 0 to this bit to clear it to 0 and clear the interrupt
request
INT13
Interrupt 13 flag. INT13 is the flag for interrupts connected to CPU interrupt level INT13I.
0
No INT13 interrupt is pending
1
At least one INT13 interrupt is pending. Write a 0 to this bit to clear it to 0 and clear the interrupt
request
INT12
Interrupt 12 flag. INT12 is the flag for interrupts connected to CPU interrupt level INT12.
0
No INT12 interrupt is pending
1
At least one INT12 interrupt is pending. Write a 0 to this bit to clear it to 0 and clear the interrupt
request
INT11
Interrupt 11 flag. INT11 is the flag for interrupts connected to CPU interrupt level INT11.
0
No INT11 interrupt is pending
1
At least one INT11 interrupt is pending. Write a 0 to this bit to clear it to 0 and clear the interrupt
request
INT10
Interrupt 10 flag. INT10 is the flag for interrupts connected to CPU interrupt level INT10.
0
No INT10 interrupt is pending
1
At least one INT6 interrupt is pending. Write a 0 to this bit to clear it to 0 and clear the interrupt
request
INT9
Interrupt 9 flag. INT9 is the flag for interrupts connected to CPU interrupt level INT6.
0
No INT9 interrupt is pending
1
At least one INT9 interrupt is pending. Write a 0 to this bit to clear it to 0 and clear the interrupt
request
INT8
Interrupt 8 flag. INT8 is the flag for interrupts connected to CPU interrupt level INT6.
0
No INT8 interrupt is pending
1
At least one INT8 interrupt is pending. Write a 0 to this bit to clear it to 0 and clear the interrupt
request
INT7
System Control
Description
Interrupt 7 flag. INT7 is the flag for interrupts connected to CPU interrupt level INT7.
0
No INT7 interrupt is pending
1
At least one INT7 interrupt is pending. Write a 0 to this bit to clear it to 0 and clear the interrupt
request
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Table 115. Interrupt Flag Register (IFR) — CPU Register Field Descriptions (continued)
Bits
Field
5
INT6
4
3
2
1
0
6.5.4
Value
Description
Interrupt 6 flag. INT6 is the flag for interrupts connected to CPU interrupt level INT6.
0
No INT6 interrupt is pending
1
At least one INT6 interrupt is pending. Write a 0 to this bit to clear it to 0 and clear the interrupt
request
INT5
Interrupt 5 flag. INT5 is the flag for interrupts connected to CPU interrupt level INT5.
0
No INT5 interrupt is pending
1
At least one INT5 interrupt is pending. Write a 0 to this bit to clear it to 0 and clear the interrupt
request
INT4
Interrupt 4 flag. INT4 is the flag for interrupts connected to CPU interrupt level INT4.
0
No INT4 interrupt is pending
1
At least one INT4 interrupt is pending. Write a 0 to this bit to clear it to 0 and clear the interrupt
request
INT3
Interrupt 3 flag. INT3 is the flag for interrupts connected to CPU interrupt level INT3.
0
No INT3 interrupt is pending
1
At least one INT3 interrupt is pending. Write a 0 to this bit to clear it to 0 and clear the interrupt
request
INT2
Interrupt 2 flag. INT2 is the flag for interrupts connected to CPU interrupt level INT2.
0
No INT2 interrupt is pending
1
At least one INT2 interrupt is pending. Write a 0 to this bit to clear it to 0 and clear the interrupt
request
INT1
Interrupt 1 flag. INT1 is the flag for interrupts connected to CPU interrupt level INT1.
0
No INT1 interrupt is pending
1
At least one INT1 interrupt is pending. Write a 0 to this bit to clear it to 0 and clear the interrupt
request
Interrupt Enable Register (IER) and Debug Interrupt Enable Register (DBGIER)
The IER is a 16-bit CPU register. The IER contains enable bits for all the maskable CPU interrupt levels
(INT1-INT14, RTOSINT and DLOGINT). Neither NMI nor XRS is included in the IER; thus, IER has no
effect on these interrupts.
You can read the IER to identify enabled or disabled interrupt levels, and you can write to the IER to
enable or disable interrupt levels. To enable an interrupt level, set its corresponding IER bit to one using
the OR IER instruction. To disable an interrupt level, set its corresponding IER bit to zero using the AND
IER instruction. When an interrupt is disabled, it is not acknowledged, regardless of the value of the INTM
bit. When an interrupt is enabled, it is acknowledged if the corresponding IFR bit is one and the INTM bit
is zero.
When using the OR IER and AND IER instructions to modify IER bits make sure they do not modify the
state of bit 15 (RTOSINT) unless a real-time operating system is present.
When a hardware interrupt is serviced or an INTR instruction is executed, the corresponding IER bit is
cleared automatically. When an interrupt is requested by the TRAP instruction the IER bit is not cleared
automatically. In the case of the TRAP instruction if the bit needs to be cleared it must be done by the
interrupt service routine.
At reset, all the IER bits are cleared to 0, disabling all maskable CPU level interrupts.
The IER register is shown in Figure 86, and descriptions of the bits follow the figure.
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Figure 86. Interrupt Enable Register (IER) — CPU Register
15
14
13
12
11
10
9
8
RTOSINT
DLOGINT
INT14
INT13
INT12
INT11
INT10
INT9
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
7
6
5
4
3
2
1
0
INT8
INT7
INT6
INT5
INT4
INT3
INT2
INT1
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 116. Interrupt Enable Register (IER) — CPU Register Field Descriptions
Bits
15
14
13
12
11
10
9
8
7
6
5
4
130
Field
Value
RTOSINT
Real-time operating system interrupt enable. RTOSINT enables or disables the CPU RTOS
interrupt.
0
Level INT6 is disabled
1
Level INT6 is enabled
DLOGINT
Data logging interrupt enable. DLOGINT enables or disables the CPU data logging interrupt.
0
Level INT6 is disabled
1
Level INT6 is enabled
INT14
Interrupt 14 enable. INT14 enables or disables CPU interrupt level INT14.
0
Level INT14 is disabled
1
Level INT14 is enabled
INT13
Interrupt 13 enable. INT13 enables or disables CPU interrupt level INT13.
0
Level INT13 is disabled
1
Level INT13 is enabled
INT12
Interrupt 12 enable. INT12 enables or disables CPU interrupt level INT12.
0
Level INT12 is disabled
1
Level INT12 is enabled
INT11
Interrupt 11 enable. INT11 enables or disables CPU interrupt level INT11.
0
Level INT11 is disabled
1
Level INT11 is enabled
INT10
Interrupt 10 enable. INT10 enables or disables CPU interrupt level INT10.
0
Level INT10 is disabled
1
Level INT10 is enabled
INT9
Interrupt 9 enable. INT9 enables or disables CPU interrupt level INT9.
0
Level INT9 is disabled
1
Level INT9 is enabled
INT8
Interrupt 8 enable. INT8 enables or disables CPU interrupt level INT8.
0
Level INT8 is disabled
1
Level INT8 is enabled
INT7
Interrupt 7 enable. INT7 enables or disables CPU interrupt level INT7.
0
Level INT7 is disabled
1
Level INT7 is enabled
INT6
Interrupt 6 enable. INT6 enables or disables CPU interrupt level INT6.
0
Level INT6 is disabled
1
Level INT6 is enabled
INT5
System Control
Description
Interrupt 5 enable.INT5 enables or disables CPU interrupt level INT5.
0
Level INT5 is disabled
1
Level INT5 is enabled
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Table 116. Interrupt Enable Register (IER) — CPU Register Field Descriptions (continued)
Bits
Field
3
INT4
2
Value
Interrupt 4 enable.INT4 enables or disables CPU interrupt level INT4.
0
Level INT4 is disabled
1
Level INT4 is enabled
INT3
1
Interrupt 3 enable.INT3 enables or disables CPU interrupt level INT3.
0
Level INT3 is disabled
1
Level INT3 is enabled
INT2
0
Description
Interrupt 2 enable.INT2 enables or disables CPU interrupt level INT2.
0
Level INT2 is disabled
1
Level INT2 is enabled
INT1
Interrupt 1 enable.INT1 enables or disables CPU interrupt level INT1.
0
Level INT1 is disabled
1
Level INT1 is enabled
The Debug Interrupt Enable Register (DBGIER) is used only when the CPU is halted in real-time
emulation mode. An interrupt enabled in the DBGIER is defined as a time-critical interrupt. When the CPU
is halted in real-time mode, the only interrupts that are serviced are time-critical interrupts that are also
enabled in the IER. If the CPU is running in real-time emulation mode, the standard interrupt-handling
process is used and the DBGIER is ignored.
As with the IER, you can read the DBGIER to identify enabled or disabled interrupts and write to the
DBGIER to enable or disable interrupts. To enable an interrupt, set its corresponding bit to 1. To disable
an interrupt, set its corresponding bit to 0. Use the PUSH DBGIER instruction to read from the DBGIER
and POP DBGIER to write to the DBGIER register. At reset, all the DBGIER bits are set to 0.
Figure 87. Debug Interrupt Enable Register (DBGIER) — CPU Register
15
14
13
12
11
10
9
8
RTOSINT
DLOGINT
INT14
INT13
INT12
INT11
INT10
INT9
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
7
6
5
4
3
2
1
0
INT8
INT7
INT6
INT5
INT4
INT3
INT2
INT1
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 117. Debug Interrupt Enable Register (DBGIER) — CPU Register Field Descriptions
Bits
15
14
13
12
Field
Value
RTOSINT
DLOGINT
INT14
Description
Real-time operating system interrupt enable. RTOSINT enables or disables the CPU RTOS
interrupt.
0
Level INT6 is disabled
1
Level INT6 is enabled
.
Data logging interrupt enable. DLOGINT enables or disables the CPU data logging interrupt
0
Level INT6 is disabled
1
Level INT6 is enabled
.
Interrupt 14 enable. INT14 enables or disables CPU interrupt level INT14
0
Level INT14 is disabled
1
Level INT14 is enabled
INT13
Interrupt 13 enable. INT13 enables or disables CPU interrupt level INT13.
0
Level INT13 is disabled
1
Level INT13 is enabled
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Table 117. Debug Interrupt Enable Register (DBGIER) — CPU Register Field Descriptions (continued)
Bits
Field
11
INT12
10
9
8
7
6
5
4
3
2
1
0
132
Value
Interrupt 12 enable. INT12 enables or disables CPU interrupt level INT12.
0
Level INT12 is disabled
1
Level INT12 is enabled
INT11
Interrupt 11 enable. INT11 enables or disables CPU interrupt level INT11.
0
Level INT11 is disabled
1
Level INT11 is enabled
INT10
Interrupt 10 enable. INT10 enables or disables CPU interrupt level INT10.
0
Level INT10 is disabled
1
Level INT10 is enabled
INT9
Interrupt 9 enable. INT9 enables or disables CPU interrupt level INT9.
0
Level INT9 is disabled
1
Level INT9 is enabled
INT8
Interrupt 8 enable. INT8 enables or disables CPU interrupt level INT8.
0
Level INT8 is disabled
1
Level INT8 is enabled
INT7
Interrupt 7 enable. INT7 enables or disables CPU interrupt level INT77.
0
Level INT7 is disabled
1
Level INT7 is enabled
INT6
Interrupt 6 enable. INT6 enables or disables CPU interrupt level INT6.
0
Level INT6 is disabled
1
Level INT6 is enabled
INT5
Interrupt 5 enable.INT5 enables or disables CPU interrupt level INT5.
0
Level INT5 is disabled
1
Level INT5 is enabled
INT4
Interrupt 4 enable.INT4 enables or disables CPU interrupt level INT4.
0
Level INT4 is disabled
1
Level INT4 is enabled
INT3
Interrupt 3 enable.INT3 enables or disables CPU interrupt level INT3.
0
Level INT3 is disabled
1
Level INT3 is enabled
INT2
Interrupt 2 enable.INT2 enables or disables CPU interrupt level INT2.
0
Level INT2 is disabled
1
Level INT2 is enabled
INT1
System Control
Description
Interrupt 1 enable.INT1 enables or disables CPU interrupt level INT1.
0
Level INT1 is disabled
1
Level INT1 is enabled
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Peripheral Interrupt Expansion (PIE)
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6.6
External Interrupt Control Registers
Three external interrupts, XINT1 –XINT3 are supported. Each of these external interrupts can be selected
for negative or positive edge triggered and can also be enabled or disabled. The masked interrupts also
contain a 16-bit free running up counter that is reset to zero when a valid interrupt edge is detected. This
counter can be used to accurately time stamp the interrupt.
Table 118. Interrupt Control and Counter Registers (not EALLOW Protected)
Name
Address Range
XINT1CR
0x0000 7070
Size (x16)
1
Description
XINT1 configuration register
XINT2CR
0x0000 7071
1
XINT2 configuration register
XINT3CR
0x0000 7072
1
XINT3 configuration register
reserved
0x0000 7073 - 0x0000 7077
5
XINT1CTR
0x0000 7078
1
XINT1 counter register
XINT2CTR
0x0000 7079
1
XINT2 counter register
XINT3CTR
0x0000 707A
1
XINT3 counter register
reserved
0x0000 707B - 0x0000 707E
5
XINT1CR through XINT3CR are identical except for the interrupt number; therefore, Figure 88 and
Table 119 represent registers for external interrupts 1 through 3 as XINTnCR where n = the interrupt
number.
Figure 88. External Interrupt n Control Register (XINTnCR)
15
1
0
Reserved
4
3
Polarity
2
Reserved
Enable
R-0
R/W-0
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 119. External Interrupt n Control Register (XINTnCR) Field Descriptions
Bits
Field
15-4
Reserved
ny writes to these (bits) must always have a value of 0.
3-2
Polarity
This read/write bit determines whether interrupts are generated on the rising edge or the
falling edge of a signal on the pin.
1
Reserved
0
Enable
Value
Description
00
Interrupt generated on a falling edge (high-to-low transition)
01
Interrupt generated on a rising edge (low-to-high transition)
10
Interrupt generated on a falling edge (high-to-low transition)
11
Interrupt generated on both a falling edge and a rising edge (high-to-low and low-to-high
transition)
ny writes to these (bits) must always have a value of 0.
This read/write bit enables or disables external interrupt XINTn.
0
Disable interrupt
1
Enable interrupt
For XINT1/XINT2/XINT3, there is also a 16-bit counter that is reset to 0x000 whenever an interrupt edge is
detected. These counters can be used to accurately time stamp an occurrence of the interrupt. XINT1CTR
through XINT3CTR are identical except for the interrupt number; therefore, Figure 89 and Table 120
represent registers for the external interrupts as XINTnCTR, where n = the interrupt number.
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Figure 89. External Interrupt n Counter (XINTnCTR) (Address 7078h)
15
0
INTCTR[15-8]
R-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 120. External Interrupt n Counter (XINTnCTR) Field Descriptions
Bits
Field
Description
15-0
INTCTR
This is a free running 16-bit up-counter that is clocked at the SYSCLKOUT rate. The counter value is
reset to 0x0000 when a valid interrupt edge is detected and then continues counting until the next valid
interrupt edge is detected. When the interrupt is disabled, the counter stops. The counter is a free-running
counter and wraps around to zero when the max value is reached. The counter is a read only register and
can only be reset to zero by a valid interrupt edge or by reset.
134
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VREG/BOR/POR
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7
VREG/BOR/POR
Although the core and I/O circuitry operate on two different voltages, these devices have an on-chip
voltage regulator (VREG) to generate the VDD voltage from the VDDIO supply. This eliminates the cost and
area of a second external regulator on an application board. Additionally, internal power-on reset (POR)
and brown-out reset (BOR) circuits monitor both the VDD and VDDIO rails during power-up and run mode,
eliminating a need for any external voltage supervisory circuits.
The VDD BOR is only valid when the VREG is enabled. If VREG is disabled, and external LDO is used for
1.8V, then there is no BOR functIon on VDD.
7.1
On-chip Voltage Regulator (VREG)
An on-chip voltage regulator facilitates the powering of the device without adding the cost or board space
of a second external regulator. This linear regulator generates the core VDD voltage from the VDDIO supply.
Therefore, although capacitors are required on each VDD pin to stabilize the generated voltage, power
need not be supplied to these pins to operate the device. Conversely, the VREG can be bypassed or
overdriven, should power or redundancy be the primary concern of the application.
7.1.1
Using the on-chip VREG
To utilize the on-chip VREG, the VREGENZ pin should be pulled low and the appropriate recommended
operating voltage should be supplied to the VDDIO and VDDA pins. In this case, the VDD voltage needed by
the core logic will be generated by the VREG. Each VDD pin requires on the order of 1.2 μF capacitance
for proper regulation of the VREG. These capacitors should be located as close as possible to the device
pins. See the TMS320F28027, TMS320F28026, TMS320F28025, TMS320F28024, TMS320F28023,
TMS320F28022 Microntroller (MCU) Data Manual (SPRS523) for the acceptable range of capacitance.
7.1.2
Bypassing the on-chip VREG
To conserve power, it is also possible to bypass the on-chip VREG and supply the core logic voltage to
the VDD pins with an external regulator. To enable this option, the VREGENZ pin must be pulled high. See
the TMS320F28027, TMS320F28026, TMS320F28025, TMS320F28024, TMS320F28023,
TMS320F28022 Microntroller (MCU) Data Manual (SPRS523) for the acceptable range of voltage that
must be supplied to the VDD pins.
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7.2
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On-chip Power-On Reset (POR) and Brown-Out Reset (BOR) Circuit
Two on-chip supervisory circuits, the power-on reset (POR) and the brown-out reset (BOR) remove the
burden of monitoring the VDD and VDDIO supply rails from the application board. The purpose of the POR is
to create a clean reset throughout the device during the entire power-up procedure. The trip point is a
looser, lower trip point than the BOR, which watches for dips in the VDD or VDDIO rail during device
operation. The POR function is present on both VDD and VDDIO rails at all times. After initial device powerup, the BOR function is present on VDDIO at all times, and on VDD when the internal VREG is enabled
(VREGENZ pin is pulled low). Both functions pull the XRS pin low when one of the voltages is below their
respective trip point. Additionally, when monitoring the VDD rail, the BOR pulls XRS low when VDD is above
its overvoltage trip point. See the device datasheet for the various trip points as well as the delay time
from the removal of the fault condition to the release of the XRS pin.
A bit is provided in the BORCFG register (address 0x985) to disable both the VDD and VDDIO BOR
functions. The default state of this bit is to enable the BOR function. When the BOR functions are
disabled, the POR functions will remain enabled. See Table 7-1 for a description of the BORCFG register.
The BORCFG register is only reset by the XRS signal.
Figure 90. BOR Configuration (BORCFG) Register
15
3
2
Reserved
R-0
R-1
1
0
Reserved
BORENZ
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 121. BOR Configuration (BORCFG) Field Descriptions
Bits
Field
15-3
Reserved
2
Reserved
1
Reserved
0
BORENZ
136
System Control
Value
Description
Any writes to these bits must always have a value of 0.
1
Reads always return a one. Writes have no effect.
Any writes to these bits must always have a value of 0.
BOR enable active low bit.
0
BOR functions are enabled.
1
BOR functions are disabled.
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Appendix A Revision History
This document has been revised to include the following technical changes.
Table 122. Revisions to this Document
Location
Additions/Deletions/Edits
FIGURES
Changed the chapter name to System Control
Figure 7
Changed STDBYWAIT from R/W-1 to R/W-0x1FF
Figure 8
Changed ACTIVEWAIT from R/W-1 to R/W-0x1FF
Figure 9
Changed RANDWAIT and PAGEWAIT from R/W-1 to R/W-0xF
Figure 10
Changed OTPWAIT from R/W-1 to R/W-0x1F
Table 12
Changed reset value for CSMSCR from 0x005F to 0x002F
Figure 11
Revised the CSMSCR register figure
Figure 12
Added the Note underneath the flow chart, beginning "Any read of the CSM password
would yield 0x0000 until the device is unlocked...."
Figure 18
Changed CLKCTL[TRM2CLKPRESCALE] to CLKCTL[TMRCLKPRESCALE]
Figure 20
For the XCLKINSEL bit, changed R/W-1 to R/W-0
Figure 23
Revised this figure
Figure 30
Table 35
For QUALSTDBY, changed R/W-1 to R/W-0x3F.
Moved the default from 2 OSCCLKs to 65 OSCCLKs
Figure 38
For all TIMERxTIMH, TIMERxPRD, TIMERxPRDH, TIMERxTCR, and TIMERxTPR
register figures, changed x=1,2,3 to x=0,1,2
Figure 40
For PRD, changed R/W-0 to R/W-1
Figure 82
Changed R/W1C-1 to R/W1C-0
Figure 90
Added this register.
SECTIONS
Section 3.2
Added /exit to the end of the sentence
Section 3.2.1
Following the bullet INTOSC1 (Internal zero-pin Oscillator 1), added "This is the
default clock source upon reset"
Section 3.2.3.1
For #4, changed "an MCLKCLR will be issued" to "write a 1 to MCLKCLR."
Section 3.2.5
Deleted "internal or external" from the first paragraph. Deleted text "either from the
X1/X2 or XCLKIN input."
Section 3.2.8
Deleted sentence beginning, "When the CPU writes to the PLLCR[DIV] bits..."
Section 3.5
Revised the intro paragraphs to this section.
After the figure, added this bolded sentence to the paragraph beginning "The general
operation of the CPU-timer is as follows:" The counter decrements once every
(TPR[TDDRH:TDDR]+1) SYSCLKOUT cycles, where TDDRH:TDDR is the timer
divider.
Section 4.1.1
Deleted the device name at the beginning of the Note
Section 3.2.6
Set MCLKRS, NMIRS, and XRS pins to active low.
Section 3.3.1
In the Wakeup from STANDBY: paragraph, changed "when the device wakes up from
HALT" to "when the device wakes up from STANDBY."
Section 7
Added the last sentence to this section beginning, "The VDD BOR is only valid when the
VREG is enabled..."
Section 7.2
Modified a sentence in the last paragraph from: "The default state of this bit is enabled"
to "The default state of this bit is to enable the BOR function."
Section 7
Added the last sentence to this section beginning, "The VDD BOR is only valid when the
VREG is enabled..."
TABLES
Table 25
For the CLOCKFAIL bit, Type 1, added "this bit will be set in the event of any clock
failure."
Table 28
Added "reset value of this counter is zero" to the description.
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Revision History 137
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Table 122. Revisions to this Document (continued)
Location
138
Additions/Deletions/Edits
Table 31
Added text beginning "When the missing clock detection..." to the bit description for
MCLKSTS
Table 29
Revised the bit description for NMIWDPRD.
Table 31
Added values 0 and 1 to the description for bit 15, NORMRDYE; Changed X1, X1/X2
to just X1/X2 for bit 5, OSCOFF
Changed "the CPU will be powered by.." to "the CPU will be clocked by.." for bit 4,
MCLKCLR
Table 34
Added the text in bold to this sentence: "When the signal is held low for enough time
and driven high, this will asynchronously release the PLL"
Table 40
Completely changed the description of bits 5-3, value "Other"
Table 51
Changed GPIO32-GPIO38 to GPIO32-GPIO44 for these registers: GPBDAT, GPBSET,
GPBCLEAR, GPBTOGGLE
Table 102
Revised the value and description columns for bits 7:0
Table 103
Revised the value and description columns for bits 7:0
Table 104
Revised the value and description column
Revision History
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