I have posed the same question on the Freescale community forum but I thought It would be worth giving it a go here as well.
After my previous post: "uCOS interfering with timing on MOD54115" I got various suggestions about achieving what I want by linking an mcPWM event to a DMA transfer, both here and on the Freescale community forum.
I fully agree: it is definitely the way to do things.
As suggested I had a look at the PeriodicAD example in the development kit and looked at V3 of the reference of the MCF54418 reference manual.
A lot became clear and setting up the eDMA module is fairly easy and understandable, mainly because of the example. In the reference manual I have found that I need to use and set up DMA channel 57 to link the DMA transfer to a register value match in the mcPWM module.
That is where I get stuck: I have found that to enable the DMA transfer bit VALDE in register PWM_SMnDMAEN needs to be set. What I can't find is how to link the DMA transfer to a particular PWM_SMnVALm register value match.
There is a lot of info on selecting particular capture DMA events (channel 56), equally lots on generating interrupts on particular value register matches and lots of info on setting up "Output triggers" on various value register matches but I can't find any info on setting up DMA events on specific value register matches.
Could it be that I need to use one of the other methods (interrupts/ output triggers) and simply not enable the Interrupts or output trigger links to the internal ADC's ?
Its likely to be a case of "glaringly obvious once pointed out"
but for the moment I can't find it.Any suggestion very much appreciated.
