topic Re: Encoder counting on FTM of KV58F in Kinetis Microcontrollers

Encoder counting on FTM of KV58F

a8Chcx — Tue, 01 Aug 2017 20:03:48 GMT

Hi,

I am trying to use demo application to do encoder(PhA and PhB) on FTM1 and FTM2 of KV58F.

I found the counting is related to "ftmInfo.prescale = kFTM_Prescale_Divide_32;//kFTM_Prescale_Divide_32;"

If I use kFTM_Prescale_Divide_1, I got much more counting. Why? It should not be related to FTM clock, right?

Thanks,

Christie

Re: Encoder counting on FTM of KV58F

a8Chcx — Wed, 02 Aug 2017 13:36:45 GMT

Hi,

I set INIT=0, MOD=65535 in sample project.

If I select pre_scale=1, the counts I get are 32 times of pre-scale=32.

Can anybody tell me why? My understanding is that the counts should be the same?

Thanks,

Christie

Re: Encoder counting on FTM of KV58F

Robin_Shen — Fri, 04 Aug 2017 06:47:25 GMT

Hi Christie,

Please refer the 'Figure 44-3. FTM block diagram' in KV5XP144M240RM.

The FTM counter clock is the selected clock divided by the prescaler.

Best Regards,

Robin

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