Revisions Affected

B, C

Details

When SDFM comparator settings—such as filter type, lower/upper threshold, or comparator OSR (COSR) settings—are dynamically changed during run time, spurious comparator events will be triggered. The spurious comparator event will trigger a corresponding CPU interrupt, CLA task, ePWM X-BAR events, and GPIO output X-BAR events if configured appropriately.

Workarounds

When comparator settings need to be changed dynamically, follow the procedure below to ensure spurious comparator events do not generate a CPU interrupt or CLA task:

1. Disable the SDFM comparator interrupt.
2. Change comparator settings such as lower/upper threshold, filter type, or COSR.
3. COSR value should be greater than or equal to 5.
4. Delay for at least a latency of comparator filter + 5 SD-Cx clock cycles.
5. Enable the SDFM comparator interrupt.

When comparator settings need to be changed dynamically, follow the procedure below to ensure spurious comparator events do not trigger X-BAR events (ePWM X-BAR and GPIO output X-BAR events):

1. Disable the SDFM X-BAR trip events in the corresponding X-BAR registers (ePWM X-BAR or GPIO X-BAR event).
2. Change comparator settings such as lower/upper threshold, filter type, or COSR.
3. COSR value should be greater than or equal to 5.
4. Delay for at least a latency of comparator filter + 5 SD-Cx clock cycles.
5. Enable the SDFM X-BAR trip events in the corresponding X-BAR registers (ePWM X-BAR or GPIO X-BAR event).