[76] LPCOMP: READY event is set sooner than it should

This anomaly applies to IC Rev. Engineering C, build codes QFAA-BB0, CHAA-BA0, CIAA-BA0.

It was inherited from the previous IC revision Engineering B.

Symptoms

May receive unexpected events and wakeups from LPCOMP.

Conditions

LPCOMP is configured to send an event or to wake up the chip. LPCOMP.TASKS_START task is set and LPCOMP.EVENTS_READY event has been received.

Consequences

Unpredictable system behavior caused by falsely triggered events and wakeups.

Workaround

Use the following configuration sequence.
  1. Configure the LPCOMP to send an event or wake up the chip, but do not enable any PPI channels or IRQ to be triggered from the LPCOMP events.
  2. Trigger the LPCOMP.TASKS_START task and wait for the LPCOMP.EVENTS_READY event.
  3. After receiving the LPCOMP.EVENTS_READY event wait for 115 µs.
  4. After 115 µs, clear the LPCOMP.EVENTS_DOWN, LPCOMP.EVENTS_UP, and LPCOMP.EVENTS_CROSS events. LPCOMP is now ready to be used.

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