Forum Discussion

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

Stream to Memory sgdma transfers

I am trying to do a stream-to-memory sgdma transfer using the start of packet and end of packet signals. My question is how do I set up the descriptors for this type of transfer? Do I ne...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

Yes, but before you need to call a function to make the descriptor for you. You will need to create a chain of two descriptors (the second one having the OWNED_BY_HW bit set to 0 to stop the SGDMA). There are some functions in the driver that can make a stream-to-memory descriptor for you. If you put 0 as length, the SGDMA will transfer data until it meets an end-of-packet signal.

Have a look at the datasheet (http://www.altera.com/literature/ug/ug_embedded_ip.pdf), pages 25-6 to 25-8 and 25-16 to 25-22.