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ICC_IGRPEN1
AArch32 Registers
AArch64 Registers
AArch32 Instructions
AArch64 Instructions
Index by Encoding
External Registers
External Registers by Offset
Registers by Functional Group
Proprietary Notice

ICC_IGRPEN1, Interrupt Controller Interrupt Group 1 Enable register

The ICC_IGRPEN1 characteristics are:

Purpose

Controls whether Group 1 interrupts are enabled for the current Security state.

Configuration

This register is banked between ICC_IGRPEN1 and ICC_IGRPEN1_S and ICC_IGRPEN1_NS.

AArch32 System register ICC_IGRPEN1 bits [31:0] (ICC_IGRPEN1_S) are architecturally mapped to AArch64 System register ICC_IGRPEN1_EL1[31:0] (ICC_IGRPEN1_EL1_S).

AArch32 System register ICC_IGRPEN1 bits [31:0] (ICC_IGRPEN1_NS) are architecturally mapped to AArch64 System register ICC_IGRPEN1_EL1[31:0] (ICC_IGRPEN1_EL1_NS).

This register is present only when FEAT_AA32EL1 is implemented and GICv3 is implemented. Otherwise, direct accesses to ICC_IGRPEN1 are UNDEFINED.

Attributes

ICC_IGRPEN1 is a 32-bit register.

This register has the following instances:

Field descriptions

313029282726252423222120191817161514131211109876543210
RES0Enable

Bits [31:1]

Reserved, RES0.

Enable, bit [0]

Enables Group 1 interrupts for the current Security state.

EnableMeaning
0b0

Group 1 interrupts are disabled for the current Security state.

0b1

Group 1 interrupts are enabled for the current Security state.

Virtual accesses to this register update ICH_VMCR.VENG1.

If EL3 is present:

The reset behavior of this field is:

Accessing ICC_IGRPEN1

The lowest Exception level at which this register can be accessed is governed by the Exception level to which IRQ is routed. This routing depends on the IRQ and NS fields of SCR or SCR_EL3 and the IMO field of HCR or HCR_EL2.

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

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

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

coprocopc1CRnCRmopc2
0b11110b0000b11000b11000b111

if !(IsFeatureImplemented(FEAT_AA32EL1) && IsFeatureImplemented(FEAT_GICv3)) then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && SCR_EL3().IRQ == '1' then Undefined(); elsif HaveEL(EL3) && EL3SDDUndefPriority() && IsFeatureImplemented(FEAT_AA32EL3) && ELUsingAArch32(EL3) && PSTATE.M != M32_Monitor && SCR().IRQ == '1' then Undefined(); elsif 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); elsif ICC_SRE().SRE == '0' then Undefined(); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2) && ICH_HCR_EL2().TALL1 == '1' then AArch64_AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA32EL2) && ELUsingAArch32(EL2) && ICH_HCR().TALL1 == '1' then AArch32_TakeHypTrapException(0x03); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2) && HCR_EL2().IMO == '1' then R(t) = ICV_IGRPEN1(); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA32EL2) && ELUsingAArch32(EL2) && HCR().IMO == '1' then R(t) = ICV_IGRPEN1(); elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && SCR_EL3().IRQ == '1' then if EL3SDDUndef() then Undefined(); else AArch64_AArch32SystemAccessTrap(EL3, 0x03); end; elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_AA32EL3) && ELUsingAArch32(EL3) && PSTATE.M != M32_Monitor && SCR().IRQ == '1' then if EL3SDDUndef() then Undefined(); else AArch32_TakeMonitorTrapException(); end; elsif HaveEL(EL3) then R(t) = ICC_IGRPEN1_NS(); else R(t) = ICC_IGRPEN1(); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && SCR_EL3().IRQ == '1' then Undefined(); elsif HaveEL(EL3) && EL3SDDUndefPriority() && IsFeatureImplemented(FEAT_AA32EL3) && ELUsingAArch32(EL3) && SCR().IRQ == '1' then Undefined(); elsif ICC_HSRE().SRE == '0' then Undefined(); elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && SCR_EL3().IRQ == '1' then if EL3SDDUndef() then Undefined(); else AArch64_AArch32SystemAccessTrap(EL3, 0x03); end; elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_AA32EL3) && ELUsingAArch32(EL3) && SCR().IRQ == '1' then if EL3SDDUndef() then Undefined(); else AArch32_TakeMonitorTrapException(); end; elsif HaveEL(EL3) then R(t) = ICC_IGRPEN1_NS(); else R(t) = ICC_IGRPEN1(); end; elsif PSTATE.EL == EL3 then if ICC_MSRE().SRE == '0' then Undefined(); else if IsCurrentSecurityState(SS_Secure) then R(t) = ICC_IGRPEN1_S(); else R(t) = ICC_IGRPEN1_NS(); end; end; end;

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

coprocopc1CRnCRmopc2
0b11110b0000b11000b11000b111

if !(IsFeatureImplemented(FEAT_AA32EL1) && IsFeatureImplemented(FEAT_GICv3)) then Undefined(); elsif PSTATE.EL == EL0 then Undefined(); elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && SCR_EL3().IRQ == '1' then Undefined(); elsif HaveEL(EL3) && EL3SDDUndefPriority() && IsFeatureImplemented(FEAT_AA32EL3) && ELUsingAArch32(EL3) && PSTATE.M != M32_Monitor && SCR().IRQ == '1' then Undefined(); elsif 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); elsif ICC_SRE().SRE == '0' then Undefined(); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2) && ICH_HCR_EL2().TALL1 == '1' then AArch64_AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA32EL2) && ELUsingAArch32(EL2) && ICH_HCR().TALL1 == '1' then AArch32_TakeHypTrapException(0x03); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA64EL2) && !ELUsingAArch32(EL2) && HCR_EL2().IMO == '1' then ICV_IGRPEN1() = R(t); elsif EL2Enabled() && IsFeatureImplemented(FEAT_AA32EL2) && ELUsingAArch32(EL2) && HCR().IMO == '1' then ICV_IGRPEN1() = R(t); elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && SCR_EL3().IRQ == '1' then if EL3SDDUndef() then Undefined(); else AArch64_AArch32SystemAccessTrap(EL3, 0x03); end; elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_AA32EL3) && ELUsingAArch32(EL3) && PSTATE.M != M32_Monitor && SCR().IRQ == '1' then if EL3SDDUndef() then Undefined(); else AArch32_TakeMonitorTrapException(); end; elsif HaveEL(EL3) then ICC_IGRPEN1_NS() = R(t); else ICC_IGRPEN1() = R(t); end; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && SCR_EL3().IRQ == '1' then Undefined(); elsif HaveEL(EL3) && EL3SDDUndefPriority() && IsFeatureImplemented(FEAT_AA32EL3) && ELUsingAArch32(EL3) && SCR().IRQ == '1' then Undefined(); elsif ICC_HSRE().SRE == '0' then Undefined(); elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_AA64EL3) && !ELUsingAArch32(EL3) && SCR_EL3().IRQ == '1' then if EL3SDDUndef() then Undefined(); else AArch64_AArch32SystemAccessTrap(EL3, 0x03); end; elsif HaveEL(EL3) && IsFeatureImplemented(FEAT_AA32EL3) && ELUsingAArch32(EL3) && SCR().IRQ == '1' then if EL3SDDUndef() then Undefined(); else AArch32_TakeMonitorTrapException(); end; elsif HaveEL(EL3) then ICC_IGRPEN1_NS() = R(t); else ICC_IGRPEN1() = R(t); end; elsif PSTATE.EL == EL3 then if ICC_MSRE().SRE == '0' then Undefined(); else if IsCurrentSecurityState(SS_Secure) then ICC_IGRPEN1_S() = R(t); else ICC_IGRPEN1_NS() = R(t); end; end; end;

AArch32 Registers
AArch64 Registers
AArch32 Instructions
AArch64 Instructions
Index by Encoding
External Registers
External Registers by Offset
Registers by Functional Group
Proprietary Notice

2026-03-12 12:23:09, 2025-09_rel_asl1

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