RFC: Phase-Aligned PWM Disable

Nobody has claimed this yet.

Hi all,

I’d like to propose making the PWM disable phase-aligned by sampling the software enable only when the PWM is idle. This prevents mid-pulse truncation and preserves the exact duty for the final active cycle, which benefits downstream analog/power stages and multi-channel synchronization.

The full draft RFC (markdown) is here:

https://github.com/EneaDim/flexsoc/blob/main/opentitan_issues/rfc_pwm.md

I outline three approaches—(1) make it the default, or for backwards compatibility (2) enable it via a compile-time parameter, or (3) enable it via a runtime configuration bit. The attached markdown shows the default-behavior variant.

I’d welcome feedback on whether this may become the default versus parameterized/configurable, and any integration concerns.

Best regards,

Enea Dimroci

Start by reading the linked draft at opentitan_issues/rfc_pwm.md, focusing on the three proposed approaches and their integration concerns. The issue is ready only after maintainers decide whether phase-aligned disable should be the default or configurable, and define the accepted implementation scope.

Written by the indexing model from the issue text.