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Altera_Forum's avatar
Altera_Forum
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15 years ago

DMA & FIR Filter, some questions.

Hello everyone, I'd like to implement a FIR filter (because it's easy to start with) in DSPBuilder. It should make use of DMA. I finally want to integrate it into an NIOS II based system using ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

I'm going to generate a new pdf for the user guide so I can probably improve it to make it more clear that extended descriptors must only be used when the extended features are enabled.

I just found out yesterday the response ports are wired up backwards. Nobody noticed since the software still works because by the time the CPU goes to validate the data the DMA is already complete. There will be an update to the files soon (probably next week) which will correct this issue as well as add these features:

- Stop on descriptor (instead of just stopping in the middle of a transfer)

- Early done enable for reads (so that the read master doesn't have to wait for all the data to return before moving on to the next descriptor)

Both of these new features will have added code in the drivers but you shouldn't have to update the application code unless you want to make use of them.