S32K14X：How to deal with OC channel level inversion caused by FTM counter overflow

[ou_gangxun]

I am using the OC function of FTM to develop the pulse communication function of the sensor. Because of design requirements, the FTM counter must always run, but this will cause a problem: It seems that when the FTM counter overflows, or the unused OC channel causes a match because the idle time exceeds 65535, and then the OC channel is started, the OC channel will immediately flip the level. Because the software I design now needs to understand the mechanism of FTM peripherals, It would be great if you could provide FTM OC functional logic documents.

[PetrS]

Hi,

the OC mode as well as other modes are described in the device Reference manual in FTM chapter.
In OC mode the output is changed when the counter matches the value in the CnV register.
Also you can refer to AN5303 Features and Operation Modes of FlexTimer Module on S32K; https://www.nxp.com/docs/en/application-note/AN5303.pdf

BR, Petr