Signal Descriptions
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
A-6
ID021414
Non-Confidential
A.5
Generic Interrupt Controller signals
Table A-4
shows the
Generic Interrupt Controller
(GIC) signals.
Table A-4 GIC signals
Signal
Direction
Description
nFIQ[CN:0]
Input
FIQ request. Active-LOW, level sensitive, asynchronous FIQ interrupt request:
0
Activate FIQ interrupt.
1
Do not activate FIQ interrupt.
The processor treats the
nFIQ
input as level-sensitive. The
nFIQ
input must be asserted
until the processor acknowledges the interrupt.
nIRQ[CN:0]
Input
IRQ request input lines. Active-LOW, level sensitive, asynchronous interrupt request:
0
Activate interrupt.
1
Do not activate interrupt.
The processor treats the
nIRQ
input as level-sensitive. The
nIRQ
input must be asserted
until the processor acknowledges the interrupt.
nSEI[CN:0]
Input
System Error Interrupt request. Active-LOW, edge sensitive:
0
Activate SEI request.
1
Do not activate SEI request.
nVFIQ[CN:0]
Input
Virtual FIQ request. Active-LOW, level sensitive, asynchronous FIQ interrupt request:
0
Activate FIQ interrupt.
1
Do not activate FIQ interrupt.
The processor treats the
nVFIQ
input as level-sensitive. The
nVFIQ
input must be
asserted until the processor acknowledges the interrupt. If the GIC is enabled by tying the
GICCDISABLE
input pin LOW, the
nVFIQ
input pin must be tied off to HIGH. If the
GIC is disabled by tying the
GICCDISABLE
input pin HIGH, the
nVFIQ
input pin can
be driven by an external GIC in the SoC.
nVIRQ[CN:0]
Input
Virtual IRQ request. Active-LOW, level sensitive, asynchronous interrupt request:
0
Activate interrupt.
1
Do not activate interrupt.
The processor treats the
nVIRQ
input as level-sensitive. The
nVIRQ
input must be
asserted until the processor acknowledges the interrupt. If the GIC is enabled by tying the
GICCDISABLE
input pin LOW, the
nVIRQ
input pin must be tied off to HIGH. If the
GIC is disabled by tying the
GICCDISABLE
input pin HIGH, the
nVIRQ
input pin can
be driven by an external GIC in the SoC.
nVSEI[CN:0]
Input
Virtual System Error Interrupt request. Active-LOW, edge sensitive:
0
Activate virtual SEI request.
1
Do not activate virtual SEI request.
nREI[CN:0]
Input
RAM Error Interrupt request. Active-LOW, edge sensitive:
0
Activate REI request. Reports an asynchronous RAM error in the system.
1
Do not activate REI request.
nVCPUMNTIRQ[CN:0]
Output
Virtual CPU interface maintenance interrupt PPI output.
PERIPHBASE[39:18]
Input
Specifies the base address for the GIC registers. This value is sampled into the CP15
Configuration Base Address Register
(CBAR) at reset.