TPM don't work well when MOD=1

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TPM don't work well when MOD=1

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wenxue
NXP Employee
NXP Employee

hello,

 

I want to use TPM as a common timer, but met a confusing phenomenon, when MOD=1, the period is not right.

 

hardware:FRDM_KL43Z

 

TPM clock source is OSCERCLK(32.768Khz)

 

I toggle a gpio in TPM timer ISR, When MOD=1, the frequency is wrong.  It will be right if MOD set for other values.

 

Thanks.

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wayne_wang
NXP Employee
NXP Employee

could please share customer information, thanks a lot!

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Robin_Shen
NXP TechSupport
NXP TechSupport

Hi Wenxue,

Sorry for the late reply.

See below information received from our AE:

this root cause is that it need to take 2 TPM clock cycle to syncTOF flag, so if set MOD = 1, counting time is too short, and it need to generate OVERFLOW 2 times till set the TOF flag.

will notice customer not to try set MOD to 1, and add note in reference manual.

Best Regards,

Robin

 

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wenxue
NXP Employee
NXP Employee

Hi Robin,

Got it, thanks!

Best Regards,

Wenxue

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Robin_Shen
NXP TechSupport
NXP TechSupport

Hi Wenxue,

I test the project on FRDM-KL43Z board find the same phenomenon.

I will ask the Kinetis AE team for help on this case. And I will inform you as soon as I get any feedback.

Best Regards,

Robin

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wenxue
NXP Employee
NXP Employee

hello Robin,

Do you have any update?

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Robin_Shen
NXP TechSupport
NXP TechSupport

Sorry. I am still waiting for the reply from our AE.

You can see that case in our internal place:TPM don't work well when MOD=1

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wenxue
NXP Employee
NXP Employee

Thanks very much.

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