topic Re: Update pwm duty cycle at rising edge in Kinetis Microcontrollers

Update pwm duty cycle at rising edge

christophosterl — Tue, 28 May 2019 11:43:22 GMT

Hello,

I have a problem with the settings of my pwm (K27). I'm updating the duty-cycle periodically. But even if the old and new duty cycle are the same, I see a jitter on my scope. Here, the "high" phase of the output signal is longer than it should be (e.g. 22us inset of 13us). So it seems that the couter is always started during a "high" phase. Is there any possibility to adopt the new duty cycle at a rising edge? I've tried several combinations of SWRSTCNT, SYNCMODE a.s.o, but did not find the correct combination.

Do you have any ideas?

Re: Update pwm duty cycle at rising edge

Robin_Shen — Thu, 30 May 2019 01:55:36 GMT

Have you refer the methods in ftm example of MCUXpresso SDK_2.5.0_MK27FN2M0Axxx15?

Try to find examples that are similar to what you need then test.

For more detail, please read the "44.5.11.4 MOD register synchronization".

Best Regards,

Robin

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