GICC_AEOIR, CPU Interface Aliased End Of Interrupt Register

The GICC_AEOIR characteristics are:

Purpose

A write to this register performs priority drop for the specified Group 1 interrupt and, if the appropriate GICC_CTLR.EOImodeS or GICC_CTLR.EOImodeNS field == 0, also deactivates the interrupt.

Configuration

This register is present only when FEAT_GICv3_LEGACY is implemented. Otherwise, direct accesses to GICC_AEOIR are RES0.

When GICD_CTLR.DS==0, this register is an alias of the Non-secure view of GICC_EOIR. A Secure access to this register is identical to a Non-secure access to GICC_EOIR.

Attributes

GICC_AEOIR 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 signaled interrupt.

Note

INTIDs 1020-1023 are reserved and convey additional information such as spurious interrupts.

When affinity routing is not enabled:

Bits [23:13] are RES0.
For SGIs, bits [12:10] identify the CPU interface corresponding to the source PE. For all other interrupts these bits are RES0.

Accessing GICC_AEOIR

A write to this register must correspond to the most recently acknowledged Group 1 interrupt. If a value other than the last value read from GICC_AIAR is written to this register, the effect is UNPREDICTABLE.

This register is used only when System register access is not enabled. When System register access is enabled:

For AArch32 implementations, ICC_EOIR1 provides equivalent functionality.
For AArch64 implementations, ICC_EOIR1_EL1 provides equivalent functionality.

When affinity routing is enabled for a Security state, it is a programming error to use memory-mapped registers to access the GIC.

GICC_AEOIR can be accessed through the memory-mapped interfaces:

Component	Offset	Instance
GIC CPU interface	0x0024	GICC_AEOIR

This interface is accessible as follows:

When GICD_CTLR.DS == 0, accesses to this register are WO.
When an access is Secure, accesses to this register are WO.
When an access is Non-secure, accesses to this register are WO.

26/03/2024 09:49; 67c0ae5282a7629ba0ea0ba7267b43cd4f7939f6