System Control
ARM DDI 0500D
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4-242
ID021414
Non-Confidential
Table 4-217
shows the DFSR bit assignments when using the Long-descriptor translation table
format.
Table 4-217 DFSR bit assignments for Long-descriptor translation table format
Bits
Name
Function
[31:14]
-
Reserved,
RES
0.
[13]
CM
Cache maintenance fault. For synchronous faults, this bit indicates whether a cache maintenance operation
generated the fault:
0
Abort not caused by a cache maintenance operation.
1
Abort caused by a cache maintenance operation.
[12]
ExT
External abort type. This field indicates whether an AXI Decode or Slave error caused an abort:
0
External abort marked as DECERR.
1
External abort marked as SLVERR.
For aborts other than external aborts this bit always returns 0.
[11]
WnR
Write not Read bit. This field indicates whether the abort was caused by a write or a read access:
0
Abort caused by a read access.
1
Abort caused by a write access.
For faults on CP15 cache maintenance operations, including the VA to PA translation operations, this bit always
returns a value of 1.
[10]
-
Reserved,
RES
0.
[9]
-
RAO.
[8:6]
-
Reserved,
RES
0.
[5:0]
Status
Fault Status bits. This field indicates the type of exception generated. Any encoding not listed is reserved.
0b000000
Address size fault in TTBR0 or TTBR1.
0b0001LL
Translation fault, LL bits indicate level.
0b0010LL
Access fault flag, LL bits indicate level.
0b0011LL
Permission fault, LL bits indicate level.
0b010000
Synchronous external abort.
0b010001
Asynchronous external abort.
0b0101LL
Synchronous external abort on translation table walk, LL bits indicate level.
0b011000
Synchronous parity error on memory access.
0b011001
Asynchronous parity error on memory access (DFSR only).
0b0111LL
Synchronous parity error on memory access on translation table walk, first level, LL bits indicate
level.
0b100001
Alignment fault.
0b100010
Debug event.
0b110000
TLB conflict abort.
0b110101
LDREX
or
STREX
abort.