ID_AA64AFR0_EL1 | Jon's Arm Reference

Provides information about the IMPLEMENTATION DEFINED features of the PE in AArch64 state.

For general information about the interpretation of the ID registers, see 'Principles of the ID scheme for fields in ID registers'.

Configuration

This register is present only when FEAT_AA64 is implemented. Otherwise, direct accesses to ID_AA64AFR0_EL1 are UNDEFINED.

Attributes

Field descriptions

Bits [63:32]

IMPLEMENTATION DEFINED, bits [31:28]

IMPLEMENTATION DEFINED, bits [27:24]

IMPLEMENTATION DEFINED, bits [23:20]

IMPLEMENTATION DEFINED, bits [19:16]

IMPLEMENTATION DEFINED, bits [15:12]

IMPLEMENTATION DEFINED, bits [11:8]

IMPLEMENTATION DEFINED, bits [7:4]

IMPLEMENTATION DEFINED, bits [3:0]

Accessing ID_AA64AFR0_EL1

Accesses to this register use the following encodings in the System register encoding space:

MRS <Xt>, ID_AA64AFR0_EL1

op0	op1	CRn	CRm	op2
0b11	0b000	0b0000	0b0101	0b100

if !IsFeatureImplemented(FEAT_AA64) then UnimplementedIDRegister(); elsif PSTATE.EL == EL0 then if IsFeatureImplemented(FEAT_IDST) then if EL2Enabled() && HCR_EL2.TGE == '1' then AArch64.SystemAccessTrap(EL2, 0x18); else AArch64.SystemAccessTrap(EL1, 0x18); else UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && IsFeatureImplemented(FEAT_IDTE3) && SCR_EL3.TID3 == '1' then UNDEFINED; elsif EL2Enabled() && HCR_EL2.TID3 == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_IDTE3) && SCR_EL3.TID3 == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = ID_AA64AFR0_EL1; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && IsFeatureImplemented(FEAT_IDTE3) && SCR_EL3.TID3 == '1' then UNDEFINED; elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_IDTE3) && SCR_EL3.TID3 == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); else X[t, 64] = ID_AA64AFR0_EL1; elsif PSTATE.EL == EL3 then X[t, 64] = ID_AA64AFR0_EL1;

63	62	61	60	59	58	57	56	55	54	53	52	51	50	49	48	47	46	45	44	43	42	41	40	39	38	37	36	35	34	33	32
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
IMPLEMENTATION DEFINED				IMPLEMENTATION DEFINED				IMPLEMENTATION DEFINED				IMPLEMENTATION DEFINED				IMPLEMENTATION DEFINED				IMPLEMENTATION DEFINED				IMPLEMENTATION DEFINED				IMPLEMENTATION DEFINED

ID_AA64AFR0_EL1: AArch64 Auxiliary Feature Register 0

Purpose