Forum Discussion

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

DMA on a DE0

Hi all, Can someone verify for me that they have DMA to SDRAM working on a DE0 board ? I've been trying to get it to work for a couple of days, but no joy. Here's how it's set up in SOPC builde...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

Make sure you have lots of buffering in the video output otherwise the time between the frames might be so long that you end up with a buffer underflow. I would simulate your design to see whether or not the DMA is behaving as expected. Also your code fragment doesn't have any cache bypassing when it's writing to the frame buffer so if you have the data cache enabled I would address that too. The code as far as I can tell sets the DMA up correctly, but I haven't used that DMA for around 5 years so I could be overlooking something.

To do frame buffering this is way easier.... http://www.alterawiki.com/wiki/modular_sgdma_video_frame_buffer