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# 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 EL3 is capable of using AArch32, 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

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 | EnableGrp1S | EnableGrp1NS

#### Bits [31:2]

Reserved, RES0.

#### EnableGrp1S, bit [1]

Enables Group 1 interrupts for the Secure state.

EnableGrp1S | Meaning
--- | ---
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:

- On a Warm reset, this field resets to 0.

#### EnableGrp1NS, bit [0]

Enables Group 1 interrupts for the Non-secure state.

EnableGrp1NS | Meaning
--- | ---
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:

- On a Warm reset, this field resets to 0.

## 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>}

coproc | opc1 | CRn | CRm | opc2
--- | --- | --- | --- | ---
0b1111 | 0b110 | 0b1100 | 0b1100 | 0b111

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && HSTR_EL2.T12 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HSTR.T12 == '1' then AArch32.TakeHypTrapException(0x03); else UNDEFINED; elsif PSTATE.EL == EL2 then UNDEFINED; elsif PSTATE.EL == EL3 then if ICC_MSRE.SRE == '0' then UNDEFINED; else R[t] = ICC_MGRPEN1;

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

coproc | opc1 | CRn | CRm | opc2
--- | --- | --- | --- | ---
0b1111 | 0b110 | 0b1100 | 0b1100 | 0b111

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if EL2Enabled() && !ELUsingAArch32(EL2) && HSTR_EL2.T12 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HSTR.T12 == '1' then AArch32.TakeHypTrapException(0x03); else UNDEFINED; elsif PSTATE.EL == EL2 then UNDEFINED; elsif PSTATE.EL == EL3 then if ICC_MSRE.SRE == '0' then UNDEFINED; else ICC_MGRPEN1 = R[t];

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

26/03/2024 09:49; 67c0ae5282a7629ba0ea0ba7267b43cd4f7939f6

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