The ID_ISAR6 characteristics are:
Provides information about the instruction sets implemented by the PE in AArch32 state.
Must be interpreted with ID_ISAR0, ID_ISAR1, ID_ISAR2, ID_ISAR3, ID_ISAR4 and ID_ISAR5.
For general information about the interpretation of the ID registers see 'Principles of the ID scheme for fields in ID registers' in the Arm® Architecture Reference Manual, Armv8, for Armv8-A architecture profile, section G7.1.3.
AArch32 System register ID_ISAR6 bits [31:0] are architecturally mapped to AArch64 System register ID_ISAR6_EL1[31:0] .
This register is present only from Armv8.2. Otherwise, direct accesses to ID_ISAR6 are RES0 from EL1, EL2, and EL3.
ID_ISAR6 is a 32-bit register.
The ID_ISAR6 bit assignments are:
31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
RES0 | I8MM | BF16 | SPECRES | SB | FHM | DP | JSCVT |
Reserved, RES0.
Indicates support for Advanced SIMD and floating-point Int8 matrix multiplication instructions in AArch32 state. Defined values are:
I8MM | Meaning |
---|---|
0b0000 |
Int8 matrix multiplication instructions are not implemented. |
0b0001 |
VSMMLA, VSUDOT, VUMMLA, VUSMMLA, and VUSDOT instructions are implemented. |
All other values are reserved.
ARMv8.2-AA32I8MM implements the functionality identified by 0b0001.
Reserved, RES0.
Indicates support for Advanced SIMD and floating-point BFloat16 instructions in AArch32 state. Defined values are:
BF16 | Meaning |
---|---|
0b0000 |
BFloat16 instructions are not implemented. |
0b0001 |
VCVT, VCVTB, VCVTT, VDOT, VFMAL, and VMMLA instructions with BF16 operand or result types are implemented. |
All other values are reserved.
ARMv8.2-AA32BF16 implements the functionality identified by 0b0001.
Reserved, RES0.
Indicates support for Speculation invalidation instructions in AArch32 state. Defined values are:
SPECRES | Meaning |
---|---|
0b0000 |
CFPRCTX, DVPRCTX, and CPPRCTX instructions are not implemented. |
0b0001 |
CFPRCTX, DVPRCTX, and CPPRCTX instructions are implemented. |
All other values are reserved.
From Armv8.5, the only permitted value is 0b0001.
Indicates support for SB instruction in AArch32 state. Defined values are:
SB | Meaning |
---|---|
0b0000 |
SB instruction is not implemented. |
0b0001 |
SB instruction is implemented. |
All other values are reserved.
From Armv8.5, the only permitted value is 0b0001.
Indicates support for Advanced SIMD and floating-point VFMAL and VFMSL instructions in AArch32 state. Defined values are:
FHM | Meaning |
---|---|
0b0000 |
VFMAL and VMFSL instructions not implemented. |
0b0001 |
VFMAL and VMFSL instructions implemented. |
ARMv8.2-FHM implements the functionality identified by the value 0b0001.
Reserved, RES0.
Indicates support for dot product instructions in AArch32 state. Defined values are:
DP | Meaning |
---|---|
0b0000 |
No dot product instructions implemented. |
0b0001 |
VUDOT and VSDOT instructions implemented. |
All other values are reserved.
ARMv8.2-DotProd implements the functionality identified by the value 0b0001.
Reserved, RES0.
Indicates support for the Javascript conversion instruction in AArch32 state. Defined values are:
JSCVT | Meaning |
---|---|
0b0000 |
The VJCVT instruction is not implemented. |
0b0001 |
The VJCVT instruction is implemented. |
All other values are reserved.
In Armv8.0, Armv8.1 and Armv8.2 the only permitted value is 0b0000.
From Armv8.3 the only permitted value is 0b0001. This feature is identified as ARMv8.3.JSConv.
Reserved, RES0.
Accesses to this register use the following encodings:
coproc | opc1 | CRn | CRm | opc2 |
---|---|---|---|---|
0b1111 | 0b000 | 0b0000 | 0b0010 | 0b111 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && HSTR_EL2.T0 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HSTR.T0 == '1' then AArch32.TakeHypTrapException(0x03); elsif EL2Enabled() && !ELUsingAArch32(EL2) && (!IsZero(ID_ISAR6) || boolean IMPLEMENTATION_DEFINED "ID_ISAR6 trapped by HCR_EL2.TID3") && HCR_EL2.TID3 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && (!IsZero(ID_ISAR6) || boolean IMPLEMENTATION_DEFINED "ID_ISAR6 trapped by HCR.TID3") && HCR.TID3 == '1' then AArch32.TakeHypTrapException(0x03); else return ID_ISAR6; elsif PSTATE.EL == EL2 then return ID_ISAR6; elsif PSTATE.EL == EL3 then return ID_ISAR6;
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