[79] NFCT: A false EVENTS_FIELDDETECTED event occurs after the field is lost

This anomaly applies to IC Rev. Engineering B, build codes QFAA-BA0, CHAA-AA0.

Symptoms

A false EVENTS_FIELDDETECTED event occurs.

Conditions

The task TASK_SENSE is triggered within 150 µs of the event EVENTS_FIELDLOST.

Consequences

EVENTS_FIELDDETECTED will occur after a field is lost. (SHORT between eventfieldlost and taskSense should not be used since a false fieldDetected event will occur from using the task.)

Workaround

Wait 150 µs after an EVENTS_FIELDLOST event before triggering TASK_SENSE.