TMS320F28069: ePWM interrupt with ADC interrupt to generate compensated SPWM

Rafael Campos

Part Number: TMS320F28069
Other Parts Discussed in Thread: CONTROLSUITE

Hi,

I'm using the TMS320F28069 DSP to implement a SPWM control to my inverter. So far, I have the SPWM being generated by updating of CMPA and CMPB with a sine table every ePWM interrupt. Now, I would like to implement an ADC to read a voltage value and multiply the sine table by this value.

Acordding to what I've read, the ADC triggers his own interruption, correct? I would like to have these two function in the same interruption, something like:

interruption{

adc = starts adc
CMPA = adc*sine[x]

}

Is it possible?

over 7 years ago

0 Nabil Saheb over 7 years ago

TI__Prodigy 540 points

Hi Rafael

There's example code present in the ControlSUITE (www.ti.com/.../CONTROLSUITE) for TMS320F28069 called AdcSOC that shows how you can use a ePWM signal to generate ADC start of conversion. The example also shows how the conversion happens during an ADC ISR. You can probably implement the math for Sine table there. See if that works for you.

Regards
Nabil

0 Rafael Campos over 7 years ago in reply to Nabil Saheb

Prodigy 30 points

Dear Nabil, thank you for your answer. I'll try the AdcSOC code as soon as I can.
Now I would like to know if I can start a ADC inside the interrupt generated by the PWM timer, as in the example code EPwmTimerInt.

Thanks!

0 Nabil Saheb over 7 years ago in reply to Rafael Campos

TI__Prodigy 540 points

Rafael

Generally, the ePWM module can be configured to trigger the Start of Conversion of the ADC. If you would not want to use that, there is a software trigger you can also be used for SOC.

In the TRM (http://www.ti.com/litv/pdf/spruh18g) read up on the ADCSOCFRC1 register. This might be what you're looking for.

Regards

Nabil

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TMS320F28069: ePWM interrupt with ADC interrupt to generate compensated SPWM