B1.74
Instruction Set Attribute Register 0
The ID_ISAR0 characteristics are:
Purpose
Provides information about the instruction sets implemented by the processor in AArch32.
Usage constraints
This register is accessible as follows:
EL0
(NS)
EL0
(S)
EL1
(NS)
EL1
(S)
EL2 EL3
(SCR.NS = 1)
EL3
(SCR.NS = 0)
-
-
RO
RO
RO
RO
RO
Must be interpreted with ID_ISAR1, ID_ISAR2, ID_ISAR3, ID_ISAR4, and ID_ISAR5. See:
•
B1.75 Instruction Set Attribute Register 1
•
B1.76 Instruction Set Attribute Register 2
•
B1.77 Instruction Set Attribute Register 3
•
B1.78 Instruction Set Attribute Register 4
•
B1.79 Instruction Set Attribute Register 5
Configurations
ID_ISAR0 is architecturally mapped to AArch64 register ID_ISAR0_EL1. See
Instruction Set Attribute Register 0, EL1
.
There is one copy of this register that is used in both Secure and Non-secure states.
Attributes
ID_ISAR0 is a 32-bit register.
31
28 27
24 23
20 19
16 15
12 11
8 7
4 3
0
RES
0
Divide
Debug
Coproc
CmpBranch
Bitfield
BitCount
Swap
Figure B1-29 ID_ISAR0 bit assignments
[31:28]
Reserved,
RES0
.
Divide, [27:24]
Indicates the implemented Divide instructions:
0x2
•
SDIV
and
UDIV
in the T32 instruction set.
•
SDIV
and
UDIV
in the A32 instruction set.
Debug, [23:20]
Indicates the implemented Debug instructions:
0x1
BKPT
.
Coproc, [19:16]
Indicates the implemented Coprocessor instructions:
0x0
None implemented, except for separately attributed by the architecture including
CP15, CP14, Advanced SIMD and floating-point.
CmpBranch, [15:12]
B1 AArch32 system registers
B1.74 Instruction Set Attribute Register 0
100236_0100_00_en
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reserved.
B1-269
Non-Confidential
Summary of Contents for Cortex-A35
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