ADC synchronization with PWM on F2812

Hi all,

I set PWM timer mode to be up-down count mode and wonder if I can realize triggering ADC at peak and valley of the PWM timer (basically two samples during one switching period)? When I check the ADC control option in C281x PWM block, it doesn't seem to have the option that I want.

Can anyone give some thought on that? I will be grateful for your help. Thanks.

-Zhe

Answer 1

[Antonin]

Hi Zhe,

Unfortunately this is not available on the TI F2812 family of chips.

TI added this functionality on newer processors like F28069, F28377S/D, etc.

I suggest that you upgrade to a newer processor if possible.

I hope it helps,

Thanks,

Antonin.

[zhe zhang]

Hi Antonin,

Thanks for your reply. I have a few more question to ask and hope you can help.

1. If I set the waveform type to be symmetric in C2812xPWM block and ADC control to be period match, does it mean that ADC will be triggered at the peak of PWM timer as I notice that the waveform period dialog I specify is for the whole period rather than half of the period.
2. As I am switching at 40kHz and put all my critical caluations (PI control, duty cycle update, etc) within one ADC interrupt, is there any way to monitor the execution time to make sure it finishes the calculation before next interrupt gets called. Any example to look at?

Thanks again for your help!

BR,

Zhe