PWM configuration

[ranjithshanbhag]

Kerry Zhou

In attached sample code can you help me how to configure PWM in center aligned mode?

Path: LPC824_Example_Code_Bundle_IAR_r1.0\Example_SCT_PWM_2State\src

Original Attachment has been moved to: LPC824_Example_Code_Bundle_LPCXpresso_r1.0.zip

[kerryzhou]

Hi Ranjith Shanbhag,

    Thank you for your trust.

    Do you just want to configure the counter to up-down mode?

    If yes, please modify the  SCT control register, BIDIR_L and BIDIR_H to 1.

  Just like the user manual, SCT regiser description:

Please try it on your side.

Wish it helps you!

If you still have question, please let me know!

Have a great day,
Kerry

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[ranjithshanbhag]

Hi kerryzhou‌,

Thank you for your valuable reply.

What all configuration changes required? By modifying SCT control register, BIDIR_L and BIDIR_H to 1 i am unable to aceive it.
Please help me.

Regards,

Ranjith Shanbhag

[kerryzhou]

Hi Ranjith Shanbhag,

   I don't know why you said configure BIDIR_L and BIDIR_H to 1 unable to work?

  I just modify these two bits, it works on my side.

  As you know, CPWM will make the counter to up-down, so the frequency will half of the original counter up.

  This is my test result and code is in the attachment.
This project will generate 250hz at PIO0_16, 50khz PWM at PIO0_12.

Wish it helps you!

Have a great day,
Kerry

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[kerryzhou]

Hi Ranjith Shanbhag,

  How did you know it  can't achieve it?

  Please give me your test result, and tell me the details how your analysis it. I will check it.

 If it is really not OK, I will test it on my side when I have time.

Have a great day,
Kerry

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Note: If this post answers your question, please click the Correct Answer button. Thank you!
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[ranjithshanbhag]

Hi kerryzhou‌,

With reference to AN11538 SCTimer/PWM cookbook (page no 15) i have done modification in the code and tested. i am unable to get PWM output.

i need your help to move forward in my project. Please provide your thoughts.

Please find the below link for the project which you shared earlier and in same project i need center aligned configuration.
https://community.nxp.com/message/869082?commentID=869082&et=watches.email.thread#comment-869082 

Path: LPC824_Example_Code_Bundle_IAR_r1.0\Shared_Project_Source_Code\Example_SCT_PWM_2State\src

[ranjithshanbhag]

hi kerryzhou,

Any update on above discussion?

Regards,

Ranjith

[ranjithshanbhag]

Sorry @Kerry Zhou i attached wrong project. Please find the below link for the project
https://community.nxp.com/message/869082?commentID=869082&et=watches.email.thread#comment-869082 

Path: LPC824_Example_Code_Bundle_IAR_r1.0\Shared_Project_Source_Code\Example_SCT_PWM_2State\src