S32K中的主题 Re: There is a microsecond level delay when capturing the input signal of S32K142W chip

There is a microsecond level delay when capturing the input signal of S32K142W chip

FAR1234 — Tue, 23 Sep 2025 01:51:32 GMT

Dear NXP experts,

Background of the problem:
MCU: S32K142W;
Application background: Configure FTM2 as capture mode to capture three-phase Hall signals for BLDC motor control.
Problem description: Adding an instruction to reverse GPIO at the input of the FTM2_Ch0uCh1_IRQHandler() interrupt function, it was found that the capture trigger time can be delayed by up to 3.2us compared to the captured signal. As shown in the following figure:

CH1 channel (yellow waveform): FTM2 captures interrupt reversal IO port;
CH2 channel (blue waveform): periodic square wave generated by the signal generator;

My FTM2 configuration is as follows:
Configure reference information, refer to this image:

Specific configuration information of FTM2:

Looking forward to your reply, thank you.

Re: There is a microsecond level delay when capturing the input signal of S32K142W chip

_Leo_ — Tue, 23 Sep 2025 18:42:26 GMT

Thank you for your interest in our products and for contributing to our community.

Maybe the CPU is attending another interrupt, set priority according to your needs:

We hope this resolves your issue.

Re: There is a microsecond level delay when capturing the input signal of S32K142W chip

FAR1234 — Wed, 24 Sep 2025 01:24:04 GMT

Hi @_Leo_

I am glad to receive your reply.

I only set the interrupt priority of "FTM2_Ch0_Ch1_IRQHandler" to the highest priority 0, and tested again, the fault still persists. As shown in the following figure:The maximum delay time reaches 3.115us

CH1 channel (yellow waveform): FTM2 captures interrupt reversal IO port;
CH2 channel (blue waveform): periodic square wave generated by the signal generator;

According to my configuration, can you retest it on your end to see if it is normal?

Best regards

Re: There is a microsecond level delay when capturing the input signal of S32K142W chip

FAR1234 — Tue, 30 Sep 2025 06:51:37 GMT

Hi @_Leo_

Have you made any progress on this issue?
We look forward to your reply.

Best regards