12.5 Event communication with an external agent using WFE/SEV

A peripheral connected on the coherency port or any other external agent can participate in the WFE/SEV event communication of the Cortex®‑R8 processor by using the EVENTI input.

When this input is asserted, it sends an event message to all the cores in the design. This is similar to executing a SEV instruction on one core of the Cortex‑R8 processor. This enables the external agent to signal to the cores that it has released a semaphore and that the cores can leave the power-saving mode. The EVENTI input must remain HIGH at least one CLK clock cycle to be visible by the cores.

The external agent can see that at least one of the cores has executed an SEV instruction by checking the EVENTO output. This output is set HIGH for one CLK clock cycle when any of the cores executes an SEV instruction.

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