Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
13 years ago

FIFO to SGDMA, FIFO Stays FULL memory not written.

Hello all, still a little new to NIOS and avalon components, but I've been going at it for a few days and I'm a bit stumped. I setup an external counter being fed through a custom Avalon compon...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
13 years ago

--- Quote Start ---

I think you forgot to start the modular SGDMA, so there is probably a descriptor stuck in the fifo waiting for the DMA to start.

--- Quote End ---

How do you explicitly start the SGDMA?

The following 

read_csr_control(MODULAR_SGDMA_DISPATCHER_CSR_BASE);

returns 16 which from your manual should imply: Stop Descriptors is set. I try and call start_descriptors and start_dispatcher manually via 

 start_descriptors(MODULAR_SGDMA_DISPATCHER_CSR_BASE);

And if I check the control register status it's still at 16. So something isn't starting like you assumed, I'm just not sure how to get it going.