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Signal generation through PWM + DMA

Question asked by Juan Pablo VEGA on Feb 9, 2014
Latest reply on Jun 4, 2018 by DHRUV A

Hi!

 

In my project I need to generate a signal, measure it and then analyse it.

Of course, I want the generation and the measurement not to load the CPU.

 

I've already been able to make the tuple PDB/ADC/DMA work, for the acquisition part. And it's just great.

 

Now, to generate the signal, I though that something like FTM/DMA/FTM(PWM) would work, but I can't manage to trigger the DMA with the first FTM.

I'm working with the PEx and I'm only using init_xxx components.

As for the FTM, I enabled the clock, the counter, the modulus, the external trigger with CNTIN, but nothing happened. When I say that nothing happened I mean that I never seem to be interrupted by the end of the major loop of the DMA.

As for the DMA, the source muxing is set to FTMx_CHx, and the rest is almost a copy of the other DMA component.

 

I'm lost... And I'm sure it's a really stupid problem.

Has anyone had any problem related to DMA triggering via the FTM?

 

Hardware: FRDM K20D50M

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