- •Contents
- •List of Tables
- •List of Figures
- •Preface
- •About this manual
- •Product revision status
- •Intended audience
- •Using this manual
- •Conventions
- •Additional reading
- •Feedback
- •Feedback on the product
- •Feedback on this book
- •Introduction
- •1.1 About the processor
- •1.2 Extensions to ARMv6
- •1.3 TrustZone security extensions
- •1.4.1 Instruction compression
- •1.4.2 The Thumb instruction set
- •1.4.3 Java bytecodes
- •1.5 Components of the processor
- •1.5.1 Integer core
- •1.5.2 Load Store Unit (LSU)
- •1.5.3 Prefetch unit
- •1.5.4 Memory system
- •1.5.5 AMBA AXI interface
- •1.5.6 Coprocessor interface
- •1.5.7 Debug
- •1.5.8 Instruction cycle summary and interlocks
- •1.5.9 System control
- •1.5.10 Interrupt handling
- •1.6 Power management
- •1.7 Configurable options
- •1.8 Pipeline stages
- •1.9 Typical pipeline operations
- •1.9.1 Instruction progression
- •1.10.1 Extended ARM instruction set summary
- •1.10.2 Thumb instruction set summary
- •1.11 Product revisions
- •Programmer’s Model
- •2.1 About the programmer’s model
- •2.2.1 TrustZone model
- •2.2.2 How the Secure model works
- •2.2.3 TrustZone write access disable
- •2.2.4 Secure Monitor bus
- •2.3 Processor operating states
- •2.3.1 Switching state
- •2.3.2 Interworking ARM and Thumb state
- •2.4 Instruction length
- •2.5 Data types
- •2.6 Memory formats
- •2.7 Addresses in a processor system
- •2.8 Operating modes
- •2.9 Registers
- •2.9.1 The ARM state core register set
- •2.9.2 The Thumb state core register set
- •2.9.3 Accessing high registers in Thumb state
- •2.9.4 ARM state and Thumb state registers relationship
- •2.10 The program status registers
- •2.10.1 The condition code flags
- •2.10.2 The Q flag
- •2.10.4 The GE[3:0] bits
- •2.10.7 The control bits
- •2.10.8 Modification of PSR bits by MSR instructions
- •2.10.9 Reserved bits
- •2.11 Additional instructions
- •2.11.1 Load or Store Byte Exclusive
- •2.11.2 Load or Store Halfword Exclusive
- •2.11.3 Load or Store Doubleword
- •2.11.4 CLREX
- •2.12 Exceptions
- •2.12.1 New instructions for exception handling
- •2.12.2 Exception entry and exit summary
- •2.12.3 Entering an ARM exception
- •2.12.4 Leaving an ARM exception
- •2.12.5 Reset
- •2.12.6 Fast interrupt request
- •2.12.7 Interrupt request
- •2.12.8 Low interrupt latency configuration
- •2.12.9 Interrupt latency example
- •2.12.10 Aborts
- •2.12.11 Imprecise Data Abort mask in the CPSR/SPSR
- •2.12.12 Supervisor call instruction
- •2.12.13 Secure Monitor Call (SMC)
- •2.12.14 Undefined instruction
- •2.12.15 Breakpoint instruction (BKPT)
- •2.12.16 Exception vectors
- •2.12.17 Exception priorities
- •2.13 Software considerations
- •2.13.1 Branch Target Address Cache flush
- •2.13.2 Waiting for DMA to complete
- •System Control Coprocessor
- •3.1 About the system control coprocessor
- •3.1.1 System control coprocessor functional groups
- •3.1.2 System control and configuration
- •3.1.3 MMU control and configuration
- •3.1.4 Cache control and configuration
- •3.1.5 TCM control and configuration
- •3.1.6 Cache Master Valid Registers
- •3.1.7 DMA control
- •3.1.8 System performance monitor
- •3.1.9 System validation
- •3.1.10 Use of the system control coprocessor
- •3.2 System control processor registers
- •3.2.1 Register allocation
- •3.2.2 c0, Main ID Register
- •3.2.3 c0, Cache Type Register
- •3.2.4 c0, TCM Status Register
- •3.2.5 c0, TLB Type Register
- •3.2.6 c0, CPUID registers
- •3.2.7 c1, Control Register
- •3.2.8 c1, Auxiliary Control Register
- •3.2.9 c1, Coprocessor Access Control Register
- •3.2.10 c1, Secure Configuration Register
- •3.2.11 c1, Secure Debug Enable Register
- •3.2.13 c2, Translation Table Base Register 0
- •3.2.14 c2, Translation Table Base Register 1
- •3.2.15 c2, Translation Table Base Control Register
- •3.2.16 c3, Domain Access Control Register
- •3.2.17 c5, Data Fault Status Register
- •3.2.18 c5, Instruction Fault Status Register
- •3.2.19 c6, Fault Address Register
- •3.2.20 c6, Watchpoint Fault Address Register
- •3.2.21 c6, Instruction Fault Address Register
- •3.2.22 c7, Cache operations
- •3.2.23 c8, TLB Operations Register
- •3.2.24 c9, Data and instruction cache lockdown registers
- •3.2.25 c9, Data TCM Region Register
- •3.2.26 c9, Instruction TCM Region Register
- •3.2.29 c9, TCM Selection Register
- •3.2.30 c9, Cache Behavior Override Register
- •3.2.31 c10, TLB Lockdown Register
- •3.2.32 c10, Memory region remap registers
- •3.2.33 c11, DMA identification and status registers
- •3.2.34 c11, DMA User Accessibility Register
- •3.2.35 c11, DMA Channel Number Register
- •3.2.36 c11, DMA enable registers
- •3.2.37 c11, DMA Control Register
- •3.2.38 c11, DMA Internal Start Address Register
- •3.2.39 c11, DMA External Start Address Register
- •3.2.40 c11, DMA Internal End Address Register
- •3.2.41 c11, DMA Channel Status Register
- •3.2.42 c11, DMA Context ID Register
- •3.2.44 c12, Monitor Vector Base Address Register
- •3.2.45 c12, Interrupt Status Register
- •3.2.46 c13, FCSE PID Register
- •3.2.47 c13, Context ID Register
- •3.2.48 c13, Thread and process ID registers
- •3.2.49 c15, Peripheral Port Memory Remap Register
- •3.2.51 c15, Performance Monitor Control Register
- •3.2.52 c15, Cycle Counter Register
- •3.2.53 c15, Count Register 0
- •3.2.54 c15, Count Register 1
- •3.2.55 c15, System Validation Counter Register
- •3.2.56 c15, System Validation Operations Register
- •3.2.57 c15, System Validation Cache Size Mask Register
- •3.2.58 c15, Instruction Cache Master Valid Register
- •3.2.59 c15, Data Cache Master Valid Register
- •3.2.60 c15, TLB lockdown access registers
- •Unaligned and Mixed-endian Data Access Support
- •4.2 Unaligned access support
- •4.2.1 Legacy support
- •4.2.2 ARMv6 extensions
- •4.2.3 Legacy and ARMv6 configurations
- •4.2.4 Legacy data access in ARMv6 (U=0)
- •4.2.5 Support for unaligned data access in ARMv6 (U=1)
- •4.2.6 ARMv6 unaligned data access restrictions
- •4.3 Endian support
- •4.3.1 Load unsigned byte, endian independent
- •4.3.2 Load signed byte, endian independent
- •4.3.3 Store byte, endian independent
- •4.4 Operation of unaligned accesses
- •4.5.1 Legacy fixed instruction and data endianness
- •4.5.3 Reset values of the U, B, and EE bits
- •4.6.1 All load and store operations
- •4.7 Instructions to change the CPSR E bit
- •Program Flow Prediction
- •5.1 About program flow prediction
- •5.2 Branch prediction
- •5.2.1 Enabling program flow prediction
- •5.2.2 Dynamic branch predictor
- •5.2.3 Static branch predictor
- •5.2.4 Branch folding
- •5.2.5 Incorrect predictions and correction
- •5.3 Return stack
- •5.4 Memory Barriers
- •5.4.1 Instruction Memory Barriers (IMBs)
- •5.5.1 Execution of IMB instructions
- •Memory Management Unit
- •6.1 About the MMU
- •6.2 TLB organization
- •6.2.1 MicroTLB
- •6.2.2 Main TLB
- •6.2.3 TLB control operations
- •6.2.5 Supersections
- •6.3 Memory access sequence
- •6.3.1 TLB match process
- •6.3.2 Virtual to physical translation mapping restrictions
- •6.4 Enabling and disabling the MMU
- •6.4.1 Enabling the MMU
- •6.4.2 Disabling the MMU
- •6.4.3 Behavior with MMU disabled
- •6.5 Memory access control
- •6.5.1 Domains
- •6.5.2 Access permissions
- •6.5.3 Execute never bits in the TLB entry
- •6.6 Memory region attributes
- •6.6.1 C and B bit, and type extension field encodings
- •6.6.2 Shared
- •6.6.3 NS attribute
- •6.7 Memory attributes and types
- •6.7.1 Normal memory attribute
- •6.7.2 Device memory attribute
- •6.7.3 Strongly Ordered memory attribute
- •6.7.4 Ordering requirements for memory accesses
- •6.7.5 Explicit Memory Barriers
- •6.7.6 Backwards compatibility
- •6.8 MMU aborts
- •6.8.1 External aborts
- •6.9 MMU fault checking
- •6.9.1 Fault checking sequence
- •6.9.2 Alignment fault
- •6.9.3 Translation fault
- •6.9.4 Access bit fault
- •6.9.5 Domain fault
- •6.9.6 Permission fault
- •6.9.7 Debug event
- •6.10 Fault status and address
- •6.11 Hardware page table translation
- •6.11.2 ARMv6 page table translation subpage AP bits disabled
- •6.11.3 Restrictions on page table mappings page coloring
- •6.12 MMU descriptors
- •Level One Memory System
- •7.1 About the level one memory system
- •7.2 Cache organization
- •7.2.1 Features of the cache system
- •7.2.2 Cache functional description
- •7.2.3 Cache control operations
- •7.2.4 Cache miss handling
- •7.2.5 Cache disabled behavior
- •7.2.6 Unexpected hit behavior
- •7.3.1 TCM behavior
- •7.3.2 Restriction on page table mappings
- •7.3.3 Restriction on page table attributes
- •7.5 TCM and cache interactions
- •7.5.1 Overlapping between TCM regions
- •7.5.2 DMA and core access arbitration
- •7.5.3 Instruction accesses to TCM
- •7.5.4 Data accesses to the Instruction TCM
- •7.6 Write buffer
- •Level Two Interface
- •8.1 About the level two interface
- •8.1.1 AXI parameters for the level 2 interconnect interfaces
- •8.2 Synchronization primitives
- •8.2.3 Example of LDREX and STREX usage
- •8.3 AXI control signals in the processor
- •8.3.1 Channel definition
- •8.3.2 Signal name suffixes
- •8.3.3 Address channel signals
- •8.4 Instruction Fetch Interface transfers
- •8.4.1 Cacheable fetches
- •8.4.2 Noncacheable fetches
- •8.5 Data Read/Write Interface transfers
- •8.5.1 Linefills
- •8.5.2 Noncacheable LDRB
- •8.5.3 Noncacheable LDRH
- •8.5.4 Noncacheable LDR or LDM1
- •8.5.5 Noncacheable LDRD or LDM2
- •8.5.6 Noncacheable LDM3
- •8.5.7 Noncacheable LDM4
- •8.5.8 Noncacheable LDM5
- •8.5.9 Noncacheable LDM6
- •8.5.10 Noncacheable LDM7
- •8.5.11 Noncacheable LDM8
- •8.5.12 Noncacheable LDM9
- •8.5.13 Noncacheable LDM10
- •8.5.14 Noncacheable LDM11
- •8.5.15 Noncacheable LDM12
- •8.5.16 Noncacheable LDM13
- •8.5.17 Noncacheable LDM14
- •8.5.18 Noncacheable LDM15
- •8.5.19 Noncacheable LDM16
- •8.6 Peripheral Interface transfers
- •8.7 Endianness
- •8.8 Locked access
- •Clocking and Resets
- •9.1 About clocking and resets
- •9.2 Clocking and resets with no IEM
- •9.2.1 Processor clocking with no IEM
- •9.2.2 Reset with no IEM
- •9.3 Clocking and resets with IEM
- •9.3.1 Processor clocking with IEM
- •9.3.2 Reset with IEM
- •9.4 Reset modes
- •9.4.1 Power-on reset
- •9.4.2 CP14 debug logic
- •9.4.3 Processor reset
- •9.4.4 DBGTAP reset
- •9.4.5 Normal operation
- •Power Control
- •10.1 About power control
- •10.2 Power management
- •10.2.1 Run mode
- •10.2.2 Standby mode
- •10.2.3 Shutdown mode
- •10.2.4 Dormant mode
- •10.2.5 Communication to the Power Management Controller
- •10.3 Intelligent Energy Management
- •10.3.1 Purpose of IEM
- •10.3.2 Structure of IEM
- •10.3.3 Operation of IEM
- •Coprocessor Interface
- •11.1 About the coprocessor interface
- •11.2 Coprocessor pipeline
- •11.2.1 Coprocessor instructions
- •11.2.2 Coprocessor control
- •11.2.3 Pipeline synchronization
- •11.2.4 Pipeline control
- •11.2.5 Instruction tagging
- •11.2.6 Flush broadcast
- •11.3 Token queue management
- •11.3.1 Queue implementation
- •11.3.2 Queue modification
- •11.3.3 Queue flushing
- •11.4 Token queues
- •11.4.1 Instruction queue
- •11.4.2 Length queue
- •11.4.3 Accept queue
- •11.4.4 Cancel queue
- •11.4.5 Finish queue
- •11.5 Data transfer
- •11.5.1 Loads
- •11.5.2 Stores
- •11.6 Operations
- •11.6.1 Normal operation
- •11.6.2 Cancel operations
- •11.6.3 Bounce operations
- •11.6.4 Flush operations
- •11.6.5 Retirement operations
- •11.7 Multiple coprocessors
- •11.7.1 Interconnect considerations
- •11.7.2 Coprocessor selection
- •11.7.3 Coprocessor switching
- •Vectored Interrupt Controller Port
- •12.1 About the PL192 Vectored Interrupt Controller
- •12.2 About the processor VIC port
- •12.2.1 Synchronization of the VIC port signals
- •12.2.2 Interrupt handler exit
- •12.3 Timing of the VIC port
- •12.3.1 PL192 VIC timing
- •12.3.2 Core timing
- •12.4 Interrupt entry flowchart
- •Debug
- •13.1 Debug systems
- •13.1.1 The debug host
- •13.1.2 The protocol converter
- •13.1.3 The processor
- •13.2 About the debug unit
- •13.2.3 Secure Monitor mode and debug
- •13.2.4 Virtual addresses and debug
- •13.2.5 Programming the debug unit
- •13.3 Debug registers
- •13.3.1 Accessing debug registers
- •13.3.2 CP14 c0, Debug ID Register (DIDR)
- •13.3.3 CP14 c1, Debug Status and Control Register (DSCR)
- •13.3.4 CP14 c5, Data Transfer Registers (DTR)
- •13.3.5 CP14 c6, Watchpoint Fault Address Register (WFAR)
- •13.3.6 CP14 c7, Vector Catch Register (VCR)
- •13.3.10 CP14 c112-c113, Watchpoint Control Registers (WCR)
- •13.3.11 CP14 c10, Debug State Cache Control Register
- •13.3.12 CP14 c11, Debug State MMU Control Register
- •13.4 CP14 registers reset
- •13.5 CP14 debug instructions
- •13.5.1 Executing CP14 debug instructions
- •13.6 External debug interface
- •13.7 Changing the debug enable signals
- •13.8 Debug events
- •13.8.1 Software debug event
- •13.8.2 External debug request signal
- •13.8.3 Halt DBGTAP instruction
- •13.8.4 Behavior of the processor on debug events
- •13.8.5 Effect of a debug event on CP15 registers
- •13.9 Debug exception
- •13.10 Debug state
- •13.10.1 Behavior of the PC in Debug state
- •13.10.2 Interrupts
- •13.10.3 Exceptions
- •13.11 Debug communications channel
- •13.12 Debugging in a cached system
- •13.12.1 Data cache writes
- •13.13 Debugging in a system with TLBs
- •13.14 Monitor debug-mode debugging
- •13.14.1 Entering the debug monitor target
- •13.14.2 Setting breakpoints, watchpoints, and vector catch debug events
- •13.14.3 Setting software breakpoint debug events (BKPT)
- •13.14.4 Using the debug communications channel
- •13.15 Halting debug-mode debugging
- •13.15.1 Entering Debug state
- •13.15.2 Exiting Debug state
- •13.15.3 Programming debug events
- •13.16 External signals
- •Debug Test Access Port
- •14.1 Debug Test Access Port and Debug state
- •14.2 Synchronizing RealView ICE
- •14.3 Entering Debug state
- •14.4 Exiting Debug state
- •14.5 The DBGTAP port and debug registers
- •14.6 Debug registers
- •14.6.1 Bypass register
- •14.6.2 Device ID code register
- •14.6.3 Instruction register
- •14.6.4 Scan chain select register (SCREG)
- •14.6.5 Scan chains
- •14.6.6 Reset
- •14.7 Using the Debug Test Access Port
- •14.7.1 Entering and leaving Debug state
- •14.7.2 Executing instructions in Debug state
- •14.7.3 Using the ITRsel IR instruction
- •14.7.4 Transferring data between the host and the core
- •14.7.5 Using the debug communications channel
- •14.7.6 Target to host debug communications channel sequence
- •14.7.7 Host to target debug communications channel
- •14.7.8 Transferring data in Debug state
- •14.7.9 Example sequences
- •14.8 Debug sequences
- •14.8.1 Debug macros
- •14.8.2 General setup
- •14.8.3 Forcing the processor to halt
- •14.8.4 Entering Debug state
- •14.8.5 Leaving Debug state
- •14.8.8 Reading the CPSR/SPSR
- •14.8.9 Writing the CPSR/SPSR
- •14.8.10 Reading the PC
- •14.8.11 Writing the PC
- •14.8.12 General notes about reading and writing memory
- •14.8.13 Reading memory as words
- •14.8.14 Writing memory as words
- •14.8.15 Reading memory as halfwords or bytes
- •14.8.16 Writing memory as halfwords/bytes
- •14.8.17 Coprocessor register reads and writes
- •14.8.18 Reading coprocessor registers
- •14.8.19 Writing coprocessor registers
- •14.9 Programming debug events
- •14.9.1 Reading registers using scan chain 7
- •14.9.2 Writing registers using scan chain 7
- •14.9.3 Setting breakpoints, watchpoints and vector traps
- •14.9.4 Setting software breakpoints
- •14.10 Monitor debug-mode debugging
- •14.10.1 Receiving data from the core
- •14.10.2 Sending data to the core
- •Trace Interface Port
- •15.1 About the ETM interface
- •15.1.1 Instruction interface
- •15.1.2 Secure control bus
- •15.1.3 Data address interface
- •15.1.4 Data value interface
- •15.1.5 Pipeline advance interface
- •15.1.6 Coprocessor interface
- •15.1.7 Other connections to the core
- •Cycle Timings and Interlock Behavior
- •16.1 About cycle timings and interlock behavior
- •16.1.1 Changes in instruction flow overview
- •16.1.2 Instruction execution overview
- •16.1.3 Conditional instructions
- •16.1.4 Opposite condition code checks
- •16.1.5 Definition of terms
- •16.2 Register interlock examples
- •16.3 Data processing instructions
- •16.3.1 Cycle counts if destination is not PC
- •16.3.2 Cycle counts if destination is the PC
- •16.3.3 Example interlocks
- •16.4 QADD, QDADD, QSUB, and QDSUB instructions
- •16.6 ARMv6 Sum of Absolute Differences (SAD)
- •16.6.1 Example interlocks
- •16.7 Multiplies
- •16.8 Branches
- •16.9 Processor state updating instructions
- •16.10 Single load and store instructions
- •16.10.1 Base register update
- •16.11 Load and Store Double instructions
- •16.12 Load and Store Multiple Instructions
- •16.12.1 Load and Store Multiples, other than load multiples including the PC
- •16.12.2 Load Multiples, where the PC is in the register list
- •16.12.3 Example Interlocks
- •16.13 RFE and SRS instructions
- •16.14 Synchronization instructions
- •16.15 Coprocessor instructions
- •16.16 SVC, SMC, BKPT, Undefined, and Prefetch Aborted instructions
- •16.17 No operation
- •16.18 Thumb instructions
- •AC Characteristics
- •17.1 Processor timing diagrams
- •17.2 Processor timing parameters
- •Signal Descriptions
- •A.1 Global signals
- •A.2 Static configuration signals
- •A.3 TrustZone internal signals
- •A.4 Interrupt signals, including VIC interface
- •A.5 AXI interface signals
- •A.5.1 Instruction read port signals
- •A.5.2 Data port signals
- •A.5.3 Peripheral port signals
- •A.5.4 DMA port signals
- •A.6 Coprocessor interface signals
- •A.7 Debug interface signals, including JTAG
- •A.8 ETM interface signals
- •A.9 Test signals
- •B.1 About the differences between the ARM1136J-S and ARM1176JZ-S processors
- •B.2 Summary of differences
- •B.2.1 TrustZone
- •B.2.2 ARMv6k extensions support
- •B.2.3 Power management
- •B.2.4 SmartCache
- •B.2.7 Tightly-Coupled Memories
- •B.2.8 Fault Address Register
- •B.2.9 Fault Status Register
- •B.2.10 Prefetch Unit
- •B.2.11 System control coprocessor operations
- •B.2.13 Debug
- •B.2.14 Level two interface
- •B.2.15 Memory BIST
- •Revisions
- •Glossary
Debug
13.3Debug registers
Table 13-1 lists definitions of terms used in register descriptions.
Table 13-1 Terms used in register descriptions
Term Description
RRead-only. Written values are ignored. However, it is written as 0 or preserved by writing the same value previously read from the same fields on the same processor.
W |
Write-only. This bit cannot be read. Reads return an Unpredictable value. |
|
|
RW |
Read or write. |
|
|
C |
Cleared on read. This bit is cleared whenever the register is read. |
|
|
UNP/SBZP |
Unpredictable or Should Be Zero or Preserved (SBZP). A read to this bit returns an Unpredictable value. |
|
It is written as 0 or preserved by writing the same value previously read from the same fields on the same |
|
processor. These bits are usually reserved for future expansion. |
|
|
Core view |
This column defines the core access permission for a given bit. |
|
|
External view |
This column defines the DBGTAP debugger view of a given bit. |
|
|
Read/write |
This is used when the core and the DBGTAP debugger view are the same. |
attributes |
|
|
|
On a power-on reset, all the CP14 debug registers take the values indicated by the Reset value column in the register bit field definition tables:
•Table 13-4 on page 13-8
•Table 13-6 on page 13-14
•Table 13-11 on page 13-18
•Table 13-14 on page 13-21
•Table 13-16 on page 13-22.
In these tables, - means an Undefined reset value.
13.3.1Accessing debug registers
To access the CP14 debug registers you must set Opcode_1 and CRn to 0. The Opcode_2 and CRm fields of the coprocessor instructions are used to encode the CP14 debug register number, where the register number is {<Opcode2>, <CRm>}.
Table 13-2 lists the CP14 debug register map. All of these registers are also accessible as scan chains from the DBGTAP.
Table 13-2 CP14 debug register map
Binary address |
Register |
CP14 debug register name |
Abbreviation |
||
|
|
||||
Opcode_2 |
CRm |
number |
|||
|
|
||||
|
|
|
|||
|
|
|
|
|
|
b000 |
b0000 |
c0 |
Debug ID Register |
DIDR |
|
|
|
|
|
|
|
b000 |
b0001 |
c1 |
Debug Status and Control Register |
DSCR |
|
|
|
|
|
|
|
b000 |
b0010-b0100 |
c2-c4 |
Reserved |
- |
|
|
|
|
|
|
|
b000 |
b0101 |
c5 |
Data Transfer Register |
DTR |
|
ARM DDI 0333H |
Copyright © 2004-2009 ARM Limited. All rights reserved. |
13-5 |
ID012410 |
Non-Confidential, Unrestricted Access |
|
Debug
Table 13-2 CP14 debug register map (continued)
Binary address |
Register |
CP14 debug register name |
Abbreviation |
||
|
|
||||
Opcode_2 |
CRm |
number |
|||
|
|
||||
|
|
|
|||
|
|
|
|
|
|
b000 |
b0110 |
c6 |
Watchpoint Fault Address Register |
WFAR |
|
|
|
|
|
|
|
b000 |
b0111 |
c7 |
Vector Catch Register |
VCR |
|
|
|
|
|
|
|
b000 |
b1000-b1001 |
c8-c9 |
Reserved |
- |
|
|
|
|
|
|
|
b000 |
b1010 |
c10 |
Debug State Cache Control Register |
DSCCR |
|
|
|
|
|
|
|
b000 |
b1011 |
c11 |
Debug State MMU Control Register |
DSMCR |
|
|
|
|
|
|
|
b000 |
b1100-b1111 |
c12-c15 |
Reserved |
- |
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b001-b011 |
b0000-b1111 |
c16-c63 |
Reserved |
- |
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b100 |
b0000-b0101 |
c64-c69 |
Breakpoint Value Registers |
BVRya |
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b0110-b111 |
c70-c79 |
Reserved |
- |
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b101 |
b0000-b0101 |
c80-c85 |
Breakpoint Control Registers |
BCRya |
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b0110-b1111 |
c86-c95 |
Reserved |
- |
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b110 |
b0000-b0001 |
c96-c97 |
Watchpoint Value Registers |
WVRya |
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b0010-b1111 |
c98-c111 |
Reserved |
- |
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b111 |
b0000-b0001 |
c112-c113 |
Watchpoint Control Registers |
WCRya |
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b0010-b1111 |
c114-c127 |
Reserved |
- |
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a. y is the decimal representation for the binary number CRm.
Note
All the debug resources required for Monitor debug-mode debugging are accessible through CP14 registers. For Halting debug-mode debugging some additional resources are required. See Chapter 14 Debug Test Access Port.
13.3.2CP14 c0, Debug ID Register (DIDR)
The Debug ID Register is a read-only register that defines the configuration of debug registers in a system. Figure 13-2 shows the format of the Debug ID Register.
31 |
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20 19 |
16 15 |
12 11 |
8 |
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3 |
0 |
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WRP |
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BRP |
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Context |
Version |
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UNP/SBZ |
Variant |
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Revision |
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Debug architecture revision
Figure 13-2 Debug ID Register format
For the ARM1176JZ-S processor:
•DIDR[31:8] has the value 0x15121x
ARM DDI 0333H |
Copyright © 2004-2009 ARM Limited. All rights reserved. |
13-6 |
ID012410 |
Non-Confidential, Unrestricted Access |
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Debug
•the value of DIDR[7:0] is determined by fields in the CP15 c0 Main ID Register, as described in the field descriptions in Table 13-3.
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Table 13-3 lists the bit field definitions for the Debug ID Register. |
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Table 13-3 Debug ID Register bit field definition |
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Bits |
Read/write |
Description |
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attributes |
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[31:28] |
R |
Number of Watchpoint Register Pairs: |
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WRP |
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b0000 |
= 1 WRP |
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b0001 |
= 2 WRPs |
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… |
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b1111 |
= 16 WRPs. |
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For the ARM1176JZ-S processor these bits are b0001 (2 WRPs). |
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[27: 24] |
R |
Number of Breakpoint Register Pairs: |
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BRP |
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b0000 |
= Reserved. The minimum number of BRPs is 2. |
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b0001 |
= 2 BRPs |
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b0010 |
= 3 BRPs |
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… |
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b1111 |
= 16 BRPs. |
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For the ARM1176JZ-S processor these bits are b0101 (6 BRPs). |
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[23: 20] |
R |
Number of Breakpoint Register Pairs with context ID comparison capability: |
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Context |
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b0000 |
= 1 BRP has context ID comparison capability |
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b0001 |
= 2 BRPs have context ID comparison capability |
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… |
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b1111 |
= 16 BRPs have context ID comparison capability. |
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For the ARM1176JZ-S processor these bits are b0001 (2 BRPs). |
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[19:16] |
R |
Debug architecture version. 0x2 denotes v6.1 |
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Version |
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[15:12] |
R |
Debug architecture revision 0x1 denotes TrustZone features |
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[11:8] |
UNP/SBZP |
Reserved. |
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[7: 4] |
R |
Implementation-defined variant number, incremented on major revisions of the product. |
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Variant |
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This field is identical to bits [23:20] of the CP15 c0 Main ID Register, see c0, Main ID |
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Register on page 3-20. |
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[3: 0] |
R |
Implementation-defined revision number, incremented on minor revisions of the product. |
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Revision |
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This field is identical to bits [3:0] of the CP15 c0 Main ID Register, see c0, Main ID Register |
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on page 3-20. |
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The reason for duplicating the Variant and Revision fields here is that the Debug ID Register is accessible through scan chain 0. This enables an external debugger to determine the variant and revision numbers without stopping the core.
13.3.3CP14 c1, Debug Status and Control Register (DSCR)
The Debug Status and Control Register contains status and configuration information about the state of the debug system. Figure 13-3 on page 13-8 shows the format of the Debug Status and Control Register.
ARM DDI 0333H |
Copyright © 2004-2009 ARM Limited. All rights reserved. |
13-7 |
ID012410 |
Non-Confidential, Unrestricted Access |
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Debug |
31 30 29 28 |
20 19 18 17 16 15 14 13 12 11 10 |
9 |
8 |
7 |
6 |
5 |
2 |
1 |
0 |
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UNP/SBZP |
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wDTRfull |
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Core halted |
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rDTRfull |
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Core restarted |
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UNP/SBZP |
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Method of debug entry |
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Imprecise data abort ignored
Non-Secure World status
Not Secure Privileged Non-Invasive
Debug enable, SPNIDEN input pin
Not Secure Privileged Invasive
Debug Enable, SPIDEN input pin
Monitor debug-mode enable
Mode select
Execute ARM instruction enable
User mode access to DCC control
Interrupts disable
DbgAck
Power down disable
Sticky Undefined flag
Sticky imprecise Data Aborts flag
Sticky precise Data Abort flag
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Figure 13-3 Debug Status and Control Register format |
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Table 13-4 lists the bit field definitions for the Debug Status and Control Register. |
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Table 13-4 Debug Status and Control Register bit field definitions |
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Bits |
Core view |
External |
Reset |
Description |
|
view |
value |
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[31] |
UNP/SBZP |
UNP/SBZP |
- |
Reserved. |
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[30] |
R |
R |
0 |
The rDTRfull flag: |
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0 = rDTR empty |
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1 = rDTR full. |
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This flag is automatically set on writes by the DBGTAP debugger to |
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the rDTR and is cleared on reads by the core of the same register. No |
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writes to the rDTR are enabled if the rDTRfull flag is set. |
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[29] |
R |
R |
0 |
The wDTRfull flag: |
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0 = wDTR empty |
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1 = wDTR full. |
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This flag is automatically cleared on reads by the DBGTAP debugger |
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of the wDTR and is set on writes by the core to the same register. |
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[28:20] |
UNP/SBZP |
UNP/SBZP |
- |
Reserved. |
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[19] |
R |
R |
0 |
Imprecise Data Aborts Ignored. This read-only bit is set by the core in |
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Debug state following a Data Memory Barrier operation, and cleared |
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on exit from Debug state. When set, the core does not act on imprecise |
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data aborts. However, the sticky imprecise data abort bit is set if an |
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imprecise data abort occurs when in Debug state. |
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ARM DDI 0333H |
Copyright © 2004-2009 ARM Limited. All rights reserved. |
13-8 |
ID012410 |
Non-Confidential, Unrestricted Access |
|
Debug
Table 13-4 Debug Status and Control Register bit field definitions (continued)
Bits |
Core view |
External |
Reset |
Description |
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view |
value |
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[18] |
R |
R |
0 |
Non-secure World Status bit 0 = The processor is in Secure state. NS |
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bit = 0 or Secure Monitor mode.1 = The processor is in Non-secure |
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state. NS bit = 1 and not Secure Monitor mode. |
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[17] |
R |
R |
n/a |
Not Secure Privilege Non-Invasive Debug Enable, SPNIDEN, input |
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pin.0 = SPNIDEN input pin is HIGH.1 = SPNIDEN input pin is LOW. |
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[16] |
R |
R |
n/a |
Not Secure Privilege Invasive Debug Enable, SPIDEN, input pin.0 = |
||
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SPIDEN input pin is HIGH.1 = SPIDEN input pin is LOW. |
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[15] |
RW |
R |
0 |
The Monitor debug-mode enable bit: |
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0 |
= Monitor debug-mode disabled |
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1 |
= Monitor debug-mode enabled. |
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|
|
For the core to take a debug exception, Monitor debug-mode has to be |
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both selected and enabled, bit 14 clear and bit 15 set. |
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[14] |
R |
RW |
0 |
Mode select bit: |
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0 |
= Monitor debug-mode selected |
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1 |
= Halting debug-mode selected and enabled. |
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||
[13] |
R |
RW |
0 |
Execute ARM instruction enable bit: |
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0 |
= Disabled |
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1 |
= Enabled. |
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If this bit is set, the core can be forced to execute ARM instructions in |
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Debug state using the Debug Test Access Port. If this bit is set when |
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the core is not in Debug state, the behavior of the processor is |
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architecturally Unpredictable. For ARM1176JZ-S processors it has |
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no effect. |
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||
[12] |
RW |
R |
0 |
User mode access to comms channel control bit: |
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0 |
= User mode access to comms channel enabled |
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1 |
= User mode access to comms channel disabled. |
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If this bit is set and a User mode process tries to access the DIDR, |
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DSCR, or the DTR, the Undefined instruction exception is taken. |
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Because accessing the rest of CP14 debug registers is never possible |
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in User mode, see Executing CP14 debug instructions on page 13-27, |
||
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|
setting this bit means that a User mode process cannot access any |
||
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CP14 debug register. |
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[11] |
R |
RW |
0 |
Interrupts bit: |
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0 |
= Interrupts enabled |
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1 |
= Interrupts disabled. |
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If this bit is set, the IRQ and FIQ input signals are inhibited.a |
||
[10] |
R |
RW |
0 |
DbgAck bit. |
||
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|
If this bit is set, the DBGACK output signal (see External signals on |
||
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|
page 13-52) is forced HIGH, regardless of the processor state.a |
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[9] |
R |
RW |
0 |
Powerdown disable: |
||
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|
0 |
= DBGNOPWRDWN is LOW |
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|
|
1 |
= DBGNOPWRDWN is HIGH. |
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|
|
See External signals on page 13-52. |
||
ARM DDI 0333H |
Copyright © 2004-2009 ARM Limited. All rights reserved. |
13-9 |
ID012410 |
Non-Confidential, Unrestricted Access |
|
Debug
Table 13-4 Debug Status and Control Register bit field definitions (continued)
Bits |
Core view |
External |
Reset |
Description |
||||
view |
value |
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||||
[8] |
R |
RC |
0 |
Sticky Undefined flag: |
||||
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|
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0 = No Undefined exception trap occurred in Debug state since the last |
||||
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time this bit was cleared. |
||||
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1 = An undefined exception occurred while in Debug state since the |
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last time this bit was cleared. |
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This bit is cleared on reads of a DBGTAP debugger to the DSCR. The |
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Sticky Undefined bit does not prevent additional instructions from |
||||
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being issued. |
||||
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The Sticky Undefined bit is not set by Undefined exceptions occurring |
||||
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|
when not in Debug state. |
||||
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||||
[7] |
R |
RC |
0 |
Sticky imprecise Data Aborts flag: |
||||
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|
0 = No imprecise Data Aborts occurred since the last time this bit was |
||||
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|
cleared |
||||
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1 = An imprecise Data Abort has occurred since the last time this bit |
||||
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|
was cleared. |
||||
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|
It is cleared on reads of a DBGTAP debugger to the DSCR. |
||||
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|
|
The sticky imprecise data abort bit is only set by imprecise data aborts |
||||
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|
|
|
occurring when in Debug state. |
||||
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|
|
Note |
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|
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|||
|
|
|
|
In previous versions of the debug architecture, the sticky imprecise |
||||
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|
|
|
data abort was set when the processor took an imprecise data abort. In |
||||
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|
|
version 6.1, it is set when an imprecise data abort is detected. |
||||
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|||
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||||
[6] |
R |
RC |
0 |
Sticky precise Data Abort flag: |
||||
|
|
|
|
0 = No precise Data Abort occurred since the last time this bit was |
||||
|
|
|
|
cleared |
||||
1 = A precise Data Abort has occurred since the last time this bit was cleared.
This flag is meant to detect Data Aborts generated by instructions issued to the processor using the Debug Test Access Port. Therefore, if the DSCR[13] execute ARM instruction enable bit is a 0, the value of the sticky precise Data Abort bit is architecturally Unpredictable. For ARM1176JZ-S processors the sticky precise Data Abort bit is set regardless of DSCR[13]. It is cleared on reads of a DBGTAP debugger to the DSCR.
The sticky precise data abort bit is only set by precise data aborts occurring when in Debug state.
ARM DDI 0333H |
Copyright © 2004-2009 ARM Limited. All rights reserved. |
13-10 |
ID012410 |
Non-Confidential, Unrestricted Access |
|