2.5.3. Events

The following table lists events that can be used for multiprocessor systems:

Table 2.1. Cortex-M3 events

NameDescription
CPU0RXEV

RX event input of the Cortex-M3. Causes a wake-up from a WFE instruction.

Connect to TXEVs from other processors in a multi-processor system. Input from OR'ing TXEV signals from other processors in the system. If different processors run at different frequencies then synchronizers must be used to guarantee that TXEV is synchronous to this processor. TXEV must also be a single-cycle pulse.

Tie to 0 if not used.

CPU0TXEV

TX event output of the Cortex-M3 Event transmitted as a result of SEV instruction. This is a single-cycle pulse. You can use it to implement a more power efficient spin-lock in a multi-processor system.

In a multi-processor system, TXEV from each processor can be broadcast to the RXEV input of the other processors.


Note

The system designer can configure the IoT Subsystem with or without support for CoreSight SoC.

If CoreSight SoC is enabled, the Processor Integration Layer is exposed to the top of the IoT Subsystem and can be connected to existing systems to form a multi core system. Event ports are used as described in the table.

If CoreSight SoC is disabled, the Cortex-M3 is expected to be a standalone (single) core. The system designer might chose to connect the RX event port to DMA done signals.

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