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ICC_MGRPEN1

ICC_MGRPEN1, Interrupt Controller Monitor Interrupt Group 1 Enable register

The ICC_MGRPEN1 characteristics are:

Purpose

Controls whether Group 1 interrupts are enabled or not.

Configuration

This register is present only when FEAT_AA32EL3 is implemented, GICv3 is implemented, and EL3 is implemented. Otherwise, direct accesses to ICC_MGRPEN1 are UNDEFINED.

Attributes

ICC_MGRPEN1 is a 32-bit register.

Field descriptions

313029282726252423222120191817161514131211109876543210
RES0EnableGrp1SEnableGrp1NS

Bits [31:2]

Reserved, RES0.

EnableGrp1S, bit [1]

Enables Group 1 interrupts for the Secure state.

EnableGrp1SMeaning
0b0

Secure Group 1 interrupts are disabled.

0b1

Secure Group 1 interrupts are enabled.

The Secure ICC_IGRPEN1.Enable bit is a read/write alias of the ICC_MGRPEN1.EnableGrp1S bit.

If the highest priority pending interrupt for that PE is a Group 1 interrupt using 1 of N model, then the interrupt will target another PE as a result of the Enable bit changing from 1 to 0.

The reset behavior of this field is:

EnableGrp1NS, bit [0]

Enables Group 1 interrupts for the Non-secure state.

EnableGrp1NSMeaning
0b0

Non-secure Group 1 interrupts are disabled.

0b1

Non-secure Group 1 interrupts are enabled.

The Non-secure ICC_IGRPEN1.Enable bit is a read/write alias of the ICC_MGRPEN1.EnableGrp1NS bit.

If the highest priority pending interrupt for that PE is a Group 1 interrupt using 1 of N model, then the interrupt will target another PE as a result of the Enable bit changing from 1 to 0.

The reset behavior of this field is:

Accessing ICC_MGRPEN1

If an interrupt is pending within the CPU interface when an Enable bit becomes 0, the interrupt must be released to allow the Distributor to forward the interrupt to a different PE.

This register is only accessible when executing in Monitor mode.

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

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

coprocopc1CRnCRmopc2
0b11110b1100b11000b11000b111

if !(IsFeatureImplemented(FEAT_AA32EL3) && IsFeatureImplemented(FEAT_GICv3) && HaveEL(EL3)) then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then if EL2Enabled() && IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2) && HSTR_EL2().T12 == '1' then AArch64_AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA32EL2) && ELUsingAArch32(EL2) && HSTR().T12 == '1' then AArch32_TakeHypTrapException(0x03); else Undefined(); end; elsif PSTATE.EL == EL2 then Undefined(); elsif PSTATE.EL == EL3 then if ICC_MSRE().SRE == '0' then Undefined(); else R(t) = ICC_MGRPEN1(); end; end;

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

coprocopc1CRnCRmopc2
0b11110b1100b11000b11000b111

if !(IsFeatureImplemented(FEAT_AA32EL3) && IsFeatureImplemented(FEAT_GICv3) && HaveEL(EL3)) then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then if EL2Enabled() && IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2) && HSTR_EL2().T12 == '1' then AArch64_AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA32EL2) && ELUsingAArch32(EL2) && HSTR().T12 == '1' then AArch32_TakeHypTrapException(0x03); else Undefined(); end; elsif PSTATE.EL == EL2 then Undefined(); elsif PSTATE.EL == EL3 then if ICC_MSRE().SRE == '0' then Undefined(); else ICC_MGRPEN1() = R(t); end; end;


2026-03-26 20:27:25, 2026-03_rel

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