PWMSP002 with dithering - how to change frequency?

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Hi,

I have a problem with changing PWM frequency on the fly (XCM4500 AC, Dave 3.1.10, PWMSP002_SetPwmFreqAndDutyCycle function). With dithering off everything works fine. Problem is with dithering on (dither mode - change PWM period). In this case decreasing frequency works well but increasing frequency sometimes causes 550us interruption in PWM output. I tried directly write PRS, CR1S and DITS and GCSS register instead of use PWMSP002_SetPwmFreqAndDutyCycle. It gives no help. Can you tell me how to solve this problem?

BR
TM
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7 Replies
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Hi TM,

A bug has been found in CCUx: Shadow transfer with dither does not work. The errata sheet update was in-progress. Will update you once released.

Best regards,
Sophia
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sophia wrote:
A bug has been found in CCUx: Shadow transfer with dither does not work.


Thank you for answer. Can you tell me whether this bug affects XMC4400? If XMC4400 is free of this bug I can replace my XMC4500 by XMC4400.
Best regards,
TM
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Hi TM,

Unfortunately, the bug exists in the module (CCUx) which is the same for both XMC4400 & XMC4500.

Best regards,
Sophia
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Can you say how long it will take to remove this bug? A few months? Or maybe rather years? I tried to do software dithering but the PWM frequency is too high and the microcontroller is not able to handle this. If time is short (months) then I can wait, but if will be longer then I have to look for another solution.
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Hi TM,

I'm sorry to say that there is no fix plan for the existing products at this time being. It will only be fixed in the future products. However, you may try use 2 timers. One is generating the PWM signal, while the other is used to gate the 1st timer for 1 clock cycle every N cycles.

Best regards,
Sophia
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Hello again,

There are new devices (XMC4800). Is there CCUx module fixed in this device?

Best regards,
TM
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HI TM,

I am sorry to inform that this is not fixed on the XMC4800 device.

Regards,
Daryl
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