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Altera_Forum
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15 years ago

SGDMA Core loop problem - setting CHAIN_COMPLETED

Hello. OK, I have cut my project back so it consists of just the NIOS, SGDMA, SDRAM controller, and an onchip memory component. If I set up the SGDMA to transfer a set of bytes between t...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

Yes, I am using the NIOS /e so its not caching. I check the descriptors and the actual source & destination memory after each supposed transfer and every time its the same: the descriptor shows the 'actual bytes transferred' as the byes to transfer but right shifted 16 bits, and no change to the destination memory.

I can only think its a fault with the project as I can perform transfers with the descriptors elsewhere and execute code of the SDRAM, so it can't be a board problem, and the 'actual bytes transferred' field I cant think of any explanation for.

Ill get my LCD working and then as you say go back with SignalTap and see if I can't work out where its getting hung up.