GICC_DIR, CPU Interface Deactivate Interrupt Register
The GICC_DIR characteristics are:
When interrupt priority drop is separated from interrupt deactivation, a write to this register deactivates the specified interrupt.
GICC_DIR is a 32-bit register.
The GICC_DIR bit assignments are:
INTID, bits [23:0]
The INTID of the signaled interrupt.
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 the GICC_DIR
This register is used only when System register access is not enabled. When System register access is enabled:
- For AArch32 implementations, ICC_DIR provides equivalent functionality.
- For AArch64 implementations, ICC_DIR_EL1 provides equivalent functionality.
Writes to this register have an effect only in the following cases:
- When GICD_CTLR.DS == 1, if GICC_CTLR.EOImode == 1.
- In GIC implementations that support two Security states:
The following writes must be ignored:
- Writes to this register when the corresponding EOImode field in GICC_CTLR == 0. In systems that support system error generation, an implementation might generate a system error.
- Writes to this register when the corresponding EOImode field in GICC_CTLR == 0 and the corresponding interrupt is not active. In systems that support system error generation, an implementation might generate a system error. In implementations using the GIC Stream Protocol Interface, these writes correspond to a Deactivate packet for an interrupt that is not active. For more information, see 'Deactivate (ICC)' in ARM® Generic Interrupt Controller Architecture Specification, GIC architecture version 3.0 and version 4.0 (ARM IHI 0069).
If the corresponding EOImode field in GICC_CTLR is 1 and this register is written to without a corresponding write to GICC_EOIR or GICC_AEOIR, the interrupt is deactivated but the bit corresponding to it in the active priorities registers remains set.
When affinity routing is enabled for a Security state, it is a programming error to use memory-mapped registers to access the GIC.
GICC_DIR can be accessed through the memory-mapped interfaces:
|GIC CPU interface||0x1000||GICC_DIR|
This interface is accessible as follows:
- When GICD_CTLR.DS == 0b0 accesses to this register are WO.
- When IsAccessSecure() accesses to this register are WO.
- When !IsAccessSecure() accesses to this register are WO.