topic Re: KL02Z PWM Issue about CnV = 1 in Kinetis Microcontrollers

KL02Z PWM Issue about CnV = 1

ellenlin — Fri, 21 Sep 2018 06:38:33 GMT

Dear NXP ,

I Follow this : PWM Duty Cycle Issue - Kinetis L ( MKL26Z128 )

And we use FRDM-KL02Z , found that when we modify C0V = 1 will happen a Full Duty waveform

So we supply thePWM Duty Cycle Issue - Kinetis L ( MKL26Z128 ) to customer and let them avoid " 1 " value into C0V

Have any document about this ? ( Errata sheet ) Customer need this .

and whether this will make other module fail ? ( ADC ? UART ? any others )

this issue happen in KL02Z , How about other KL series ic ? Has already fix this ? Thanks a lot !!

Re: KL02Z PWM Issue about CnV = 1

victorjimenez — Mon, 24 Sep 2018 16:44:06 GMT

Hello,

Could you please provide more information, for example: at what frequency are you working? where in your program are you changing the duty cycle, in the interrupt or in another place?

I tried the example tpm_simple_pwm of the SDK along with the FRDM-KL02Z board. I modified the code to see the signal in a oscilloscope and I wrote "1" directly to the CnV register and everything worked fine.

I checked the errata and there is no information available regarding the behavior that you mentioned. Could you please try with the example of the SDK?

Regards,

Victor.

Re: KL02Z PWM Issue about CnV = 1

ellenlin — Tue, 25 Sep 2018 02:01:46 GMT

Dear Victor Jimenez :

Provide Code Warrior project to you ,

We use TPM1 Interrupt to modify TPM0 Duty Cycle , AND This happen ,

you can try attachment file in Code warrior IDE , THANKS!!

Re: KL02Z PWM Issue about CnV = 1

victorjimenez — Wed, 26 Sep 2018 22:03:39 GMT

Hello,

I modified the example tpm_simple_pwm from the SDK 2.3.1 to follow the steps that you mentioned. I use TPM0 interrupt to write constantly 1 in the CnV register of the TPM1 and everything worked fine, I wasn't able to reproduce the behavior that you mention.

I don't have Code Warrior IDE installed, since we are push to use our newest tools, like MCUXpresso IDE and SDK. I noticed in your example code that you are using Processor Expert, this made me think that the behavior that you are facing is due to this. Is it possible for your customer to make the migration to MCUXpresso and SDK? Please let me know if this is not an option.

Regards,

Victor.

Re: KL02Z PWM Issue about CnV = 1

ellenlin — Thu, 27 Sep 2018 01:59:49 GMT

Dear Victor Jimenez

My Customer has already use CW for several years ,

it ' s not a good choice to change IDE , Their FW Team is too large and they don't prefer this , they want a document to explain this issue .

I use TPM1 ( Period = 100uS ) Interrupt to modify TPM0 ( Period = 20 us ) Duty cycle .

Really need NXP 's Support to check this , thanks a lot !!

Re: KL02Z PWM Issue about CnV = 1

victorjimenez — Fri, 28 Sep 2018 21:22:14 GMT

Hello,

Thanks for providing more information. I ran the project that you provided and I was able to reproduce the behavior that you mentioned. However, I noticed that once I stopped the debug session the program starts to function as expected, see photo below.

It seems that the behavior is due to the debug session. In runtime, you can write one to the CnV register without any problem.

Regards,

Victor.

Re: KL02Z PWM Issue about CnV = 1

ellenlin — Sun, 30 Sep 2018 14:10:32 GMT

Dear Victor Jimenez ,

You means stop debug method , use free run then won't happen this issue ? i ' ll try this ~

and why debug method will happen this ? Customer will ask this question , i think it's very important .

Thanks a lot !!

Re: KL02Z PWM Issue about CnV = 1

ellenlin — Mon, 01 Oct 2018 02:52:44 GMT

Dear Victor Jimenez ,

I has already try the method you mentioned , but nothing was happen , stiil the same issue ,

And my customer , too . Have any document about this to explain this issue ? i has already provide PWM Duty Cycle Issue - Kinetis L ( MKL26Z128 ) answer to them and i think this can be avoid by " if " function . and customer has already accept this .

But they want a Errata answer this , thanks a lot !!!

Re: KL02Z PWM Issue about CnV = 1

victorjimenez — Tue, 02 Oct 2018 13:23:57 GMT

Hello,

When I ran your project from the debug session even if I use free run I could reproduce the behavior you mentioned. However, once I stopped/exited the debug session completely and restart the board the behavior was gone and the program was running as expected. I couldn’t reproduce the behavior while running your project without an open debug session. The behavior you are facing is due to the debug session of code warrior, not the MCU, so there are not available errata for this since the problem is not from the MCU. I’m still investigating how the debug session is messing with the time of the peripheral TPM.

Hope it helps!

Victor.

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Re: KL02Z PWM Issue about CnV = 1

ellenlin — Wed, 03 Oct 2018 01:23:01 GMT

Dear Victor Jimenez

Thanks for your help , i think why this will happen is more important ~

i 'm still can't solve the issue like you did , i has already consult the Technical Support for customer , thanks for your help !!