System Control
ARM DDI 0500D Copyright © 2013-2014 ARM. All rights reserved. 4-247
ID021414 Non-Confidential
Table 4-223 shows the HSR bit assignments.
Encoding of ISS[24:20] when HSR[31:30] is 0b00
For EC values that are nonzero and have the two most-significant bits 0b00, ISS[24:20]
provides the condition field for the trapped instruction, together with a valid flag for this field.
The encoding of this part of the ISS field is:
CV, ISS[24] Condition valid. Possible values of this bit are:
0
The COND field is not valid.
1
The COND field is valid.
When an instruction is trapped, CV is set to 1.
COND, ISS[23:20]
The Condition field for the trapped instruction. This field is valid only when CV
is set to 1.
If CV is set to 0, this field is
RES0.
When an instruction is trapped, the COND field is set to the condition the instruction was
executed with.
4.5.55 Data Fault Address Register
The DFAR characteristics are:
Purpose Holds the virtual address of the faulting address that caused a synchronous
Data Abort exception.
Usage constraints This register is accessible as follows:
Configurations DFAR (NS) is architecturally mapped to AArch64 register
FAR_EL1[31:0]. See Fault Address Register, EL1 on page 4-103.
DFAR (S) is architecturally mapped to AArch32 register HDFAR. See
Hyp Data Fault Address Register on page 4-249.
Table 4-223 HSR bit assignments
Bits Name Function
[31:26] EC
Exception class. The exception class for the exception that is taken in Hyp mode. See the ARM
®
Architecture
Reference Manual ARMv8, for ARMv8-A architecture profile for more information.
[25] IL
Instruction length. See the ARM
®
Architecture Reference Manual ARMv8, for ARMv8-A architecture profile for
more information.
[24:0] ISS
Instruction specific syndrome. See the ARM
®
Architecture Reference Manual ARMv8, for ARMv8-A architecture
profile for more information. The interpretation of this field depends on the value of the EC field. See Encoding
of ISS[24:20] when HSR[31:30] is 0b00.
EL0
(NS)
EL0
(S)
EL1
(NS)
EL1
(S)
EL2
EL3
(SCR.NS = 1)
EL3
(SCR.NS = 0)
DFAR(S) - - - RW - - RW
DFAR(NS) - - RW - RW RW -
To Next Page
Loading...
