ID_AFR0, Auxiliary Feature Register 0

The ID_AFR0 characteristics are:

Purpose

Provides information about the IMPLEMENTATION DEFINED features of the PE in AArch32 state.

Must be interpreted with the Main ID Register, MIDR.

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

Configuration

AArch32 System register ID_AFR0 bits [31:0] are architecturally mapped to AArch64 System register ID_AFR0_EL1[31:0].

This register is present only when AArch32 is supported at any Exception level. Otherwise, direct accesses to ID_AFR0 are UNDEFINED.

Attributes

ID_AFR0 is a 32-bit register.

Field descriptions

The ID_AFR0 bit assignments are:

313029282726252423222120191817161514131211109876543210
RES0IMPLEMENTATION DEFINEDIMPLEMENTATION DEFINEDIMPLEMENTATION DEFINEDIMPLEMENTATION DEFINED

Bits [31:16]

Reserved, RES0.

IMPLEMENTATION DEFINED, bits [15:12]

IMPLEMENTATION DEFINED.

IMPLEMENTATION DEFINED, bits [11:8]

IMPLEMENTATION DEFINED.

IMPLEMENTATION DEFINED, bits [7:4]

IMPLEMENTATION DEFINED.

IMPLEMENTATION DEFINED, bits [3:0]

IMPLEMENTATION DEFINED.

Accessing the ID_AFR0

Accesses to this register use the following encodings:

MRC{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <CRn>, <CRm>{, {#}<opc2>}

coprocopc1CRnCRmopc2
0b11110b0000b00000b00010b011

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) && HCR_EL2.TID3 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HCR.TID3 == '1' then AArch32.TakeHypTrapException(0x03); else return ID_AFR0; elsif PSTATE.EL == EL2 then return ID_AFR0; elsif PSTATE.EL == EL3 then return ID_AFR0;


30/03/2021 20:51; e3551d56dc294a4d55296a6c10544191ada08a8e

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