A9.2
Bypassing the CPU interface
The GIC CPU Interface is always implemented within the Cortex-A76 core.
However, you can disable it if you assert the GICCDISABLE signal HIGH at reset. If you disable the
GIC CPU interface, the input pins nVIRQ and nVFIQ can be driven by an external GIC in the SoC. GIC
system register access generates
UNDEFINED
instruction exceptions when the GICCDISABLE signal is
HIGH.
If the GIC is enabled, the input pins nVIRQ and nVFIQ must be tied off to HIGH. This is because the
internal GIC CPU interface generates the virtual interrupt signals to the cores. The nIRQ and nFIQ
signals are controlled by software, therefore there is no requirement to tie them HIGH.
A9 Generic Interrupt Controller CPU interface
A9.2 Bypassing the CPU interface
100798_0300_00_en
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Summary of Contents for Cortex-A76 Core
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