About the signal descriptions
The tables in this appendix list the Cortex-A72 processor signals, along with their direction, input or output, and a high-level description.
Some of the buses include a configurable width field, <signal>[N:0], where N = 0, 1, 2, or 3, to encode up to four cores. For example:
- nIRQ represents a core 0 interrupt request.
- nIRQ represents a core 2 interrupt request.
Some signals are specified in the form <signal>x, where x = 0, 1, 2 or 3 references core 0, core 1, core 2, or core 3, respectively. If a core is not present, the corresponding pin is removed. For example:
- PMUEVENT0[24:0] represents the core 0 PMU event bus.
- PMUEVENT3[24:0] represents the core 3 PMU event bus.
The number of signals changes depending on the configuration. For example, the CHI interface signals are not present when the processor is configured to have an ACE interface.