ARM Architecture Reference Manual ARMv7-A and ARMv7-R edition

Debug Exceptions
C4.2 Effects of debug exceptions on CP15 registers and the DBGWFAR
There are four CP15 registers that are used to record abort information:
DFAR Data Fault Address Register, see:
c6, Data Fault Address Register (DFAR) on page B3-124 for a VMSA
implementation
c6, Data Fault Address Register (DFAR) on page B4-57 for a PMSA implementation.
IFAR Instruction Fault Address Register, see:
c6, Instruction Fault Address Register (IFAR) on page B3-125 for a VMSA
implementation
c6, Instruction Fault Address Register (IFAR) on page B4-58 for a PMSA
implementation.
DFSR Data Fault Status Register, see:
c5, Data Fault Status Register (DFSR) on page B3-121 for a VMSA implementation
c5, Data Fault Status Register (DFSR) on page B4-55 for a PMSA implementation.
IFSR Instruction Fault Status Register, see:
c5, Instruction Fault Status Register (IFSR) on page B3-122 for a VMSA
implementation
c5, Instruction Fault Status Register (IFSR) on page B4-56 for a PMSA
implementation.
Their usage model for normal operation is described in:
Fault Status and Fault Address registers in a VMSA implementation on page B3-48 for a VMSA
implementation
Fault Status and Fault Address registers in a PMSA implementation on page B4-18 for a PMSA
implementation.
Additional registers might be used to return additional IMPLEMENTATION DEFINED fault status information,
see:
c5, Auxiliary Data and Instruction Fault Status Registers (ADFSR and AIFSR) on page B3-123 for a
VMSA implementation
c5, Auxiliary Data and Instruction Fault Status Registers (ADFSR and AIFSR) on page B4-56 for a
PMSA implementation.
Also, information can be returned in the Watchpoint Fault Address Register (DBGWFAR). The
implementation of the DBGWFAR depends on the Debug architecture version:
In v6 Debug it is implemented as a register in CP15 c6.
In v6.1 Debug it is implemented in CP14, and use of the CP15 alias is deprecated.
In v7 Debug it can be implemented in the Extended CP14 interface, and has no alias in CP15.
For more information, see Watchpoint Fault Address Register (DBGWFAR) on page C10-28.
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