B4.27 ICC_BPR0_EL1, Interrupt Controller Binary Point Register 0, EL1

ICC_BPR0_EL1 defines the point at which the priority value fields split into two parts, the group priority field and the subpriority field. The group priority field determines Group 0 interrupt preemption.

Bit field descriptions

ICC_BPR0_EL1 is a 32-bit register and is part of:

  • The GIC system registers functional group.
  • The GIC control registers functional group.
Figure B4-14 ICC_BPR0_EL1 bit assignments
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RES0, [31:3]
BinaryPoint, [2:0]

The value of this field controls how the 8-bit interrupt priority field is split into a group priority field, that determines interrupt preemption, and a subpriority field. The minimum value that is implemented is:


AArch64 System register ICC_BPR0_EL1 is architecturally mapped to AArch32 System register ICC_BPR0.

Virtual accesses to this register update ICH_VMCR_EL2.VBPR0.

Bit fields and details that are not provided in this description are architecturally defined. See the Arm® Generic Interrupt Controller Architecture Specification.

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