topic Re: Initial PWM output value with eFlexPWM in MCX Microcontrollers

Initial PWM output value with eFlexPWM

zorrotz — Tue, 06 Oct 2026 13:31:41 GMT

Hi,

Working with eFlexPWM of MCXA132, I want to modify the initial value for PWM23.
For that I do next steps:

1. SM1CTRL2[PWM23_INIT] = 1

2. SM1CTRL2[FRCEN] = 1
SM1CTRL2[FORCE] = 1 (note that SM1CTRL2[FORCE_SEL] is 000)

3. MCTRL[RUN] = 010

But first PWM cycle always starts with output at level 0.

Where can be the problem?

Thanks in advance

Re: Initial PWM output value with eFlexPWM

Alice_Yang — Thu, 08 Oct 2026 09:36:08 GMT

Hello @zorrotz

To help us analyze the issue, could you please share your complete project with us?

Thank you.

Alice

Re: Initial PWM output value with eFlexPWM

zorrotz — Fri, 09 Oct 2026 05:36:27 GMT

Hello,

I have found my mistake.

The reference manual has this note:

"If MCTRL[LDOK] is not set, setting MCTRL[RUN] also sets the STS[RF] flag. To prevent a CPU interrupt request, clear INTEN[RIE] before setting MCTRL[RUN]."

I am using STS[RF] to end PWM cycle, but I clear STS[RF] before doing MCTRL[RUN] = 1.

Thanks