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# ICC_DIR, Interrupt Controller Deactivate Interrupt Register

The ICC_DIR characteristics are:

## Purpose

When interrupt priority drop is separated from interrupt deactivation, a write to this register deactivates the specified interrupt.

## Configuration

AArch32 System register ICC_DIR performs the same function as AArch64 System register ICC_DIR_EL1.

This register is present only when EL1 is capable of using AArch32 and GICv3 is implemented. Otherwise, direct accesses to ICC_DIR are UNDEFINED.

## Attributes

ICC_DIR 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 | INTID

#### Bits [31:24]

Reserved, RES0.

#### INTID, bits [23:0]

The INTID of the interrupt to be deactivated.

This field has either 16 or 24 bits implemented. The number of implemented bits can be found in ICC_CTLR.IDbits and ICC_MCTLR.IDbits. If only 16 bits are implemented, bits [23:16] of this register are RES0.

## Accessing ICC_DIR

There are two cases when writing to ICC_DIR_EL1 that were UNPREDICTABLE for a corresponding GICv2 write to GICC_DIR:

- When EOImode == 0. GICv3 implementations must ignore such writes. In systems supporting system error generation, an implementation might generate an SEI.
- When EOImode == 1 but no EOI has been issued. The interrupt will be de-activated by the Distributor, however the active priority in the CPU interface for the interrupt will remain set (because no EOI was issued).

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

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

coproc | opc1 | CRn | CRm | opc2
--- | --- | --- | --- | ---
0b1111 | 0b000 | 0b1100 | 0b1011 | 0b001

if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && !ELUsingAArch32(EL3) && SCR_EL3.<IRQ,FIQ> == '11' then UNDEFINED; elsif HaveEL(EL3) && EL3SDDUndefPriority() && ELUsingAArch32(EL3) && PSTATE.M != M32_Monitor && SCR.<IRQ,FIQ> == '11' then UNDEFINED; elsif EL2Enabled() && !ELUsingAArch32(EL2) && HSTR_EL2.T12 == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && HSTR.T12 == '1' then AArch32.TakeHypTrapException(0x03); elsif ICC_SRE.SRE == '0' then UNDEFINED; elsif EL2Enabled() && !ELUsingAArch32(EL2) && ICH_HCR_EL2.TDIR == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && !ELUsingAArch32(EL2) && ICH_HCR_EL2.TC == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && ICH_HCR.TC == '1' then AArch32.TakeHypTrapException(0x03); elsif EL2Enabled() && ELUsingAArch32(EL2) && ICH_HCR.TDIR == '1' then AArch32.TakeHypTrapException(0x03); elsif EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.FMO == '1' then ICV_DIR = R[t]; elsif EL2Enabled() && !ELUsingAArch32(EL2) && HCR_EL2.IMO == '1' then ICV_DIR = R[t]; elsif EL2Enabled() && ELUsingAArch32(EL2) && HCR.FMO == '1' then ICV_DIR = R[t]; elsif EL2Enabled() && ELUsingAArch32(EL2) && HCR.IMO == '1' then ICV_DIR = R[t]; elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.<IRQ,FIQ> == '11' then if EL3SDDUndef() then UNDEFINED; else AArch64.AArch32SystemAccessTrap(EL3, 0x03); elsif HaveEL(EL3) && ELUsingAArch32(EL3) && PSTATE.M != M32_Monitor && SCR.<IRQ,FIQ> == '11' then if EL3SDDUndef() then UNDEFINED; else AArch32.TakeMonitorTrapException(); else ICC_DIR = R[t]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && !ELUsingAArch32(EL3) && SCR_EL3.<IRQ,FIQ> == '11' then UNDEFINED; elsif HaveEL(EL3) && EL3SDDUndefPriority() && ELUsingAArch32(EL3) && SCR.<IRQ,FIQ> == '11' then UNDEFINED; elsif ICC_HSRE.SRE == '0' then UNDEFINED; elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && SCR_EL3.<IRQ,FIQ> == '11' then if EL3SDDUndef() then UNDEFINED; else AArch64.AArch32SystemAccessTrap(EL3, 0x03); elsif HaveEL(EL3) && ELUsingAArch32(EL3) && SCR.<IRQ,FIQ> == '11' then if EL3SDDUndef() then UNDEFINED; else AArch32.TakeMonitorTrapException(); else ICC_DIR = R[t]; elsif PSTATE.EL == EL3 then if ICC_MSRE.SRE == '0' then UNDEFINED; else ICC_DIR = 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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