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Altera_Forum
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14 years ago

use descriptor chain in SGDMA

Hi all My current goal is to use SGDMA (ST-to-MM) to transfer video data to a memory. Later on, I'll replace the memory by PCIE IP. My problem is how to use descriptor chain in SGDMA. ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

How did you declare your sgdma_desc table?

It needs to be big enough to hold all your descriptors (3 in your case, because the second one needs to point to a third one that will stop the SGDMA).

It needs to be in a memory connected to the SGDMA descriptor read and write masters (mem A)

It needs to be in a memory that the Nios CPU can write to (i.e. the Nios' data master must be connected to mem A).

What is your memory scheme for the software? which memory is used for text, data, heap, stack and bss?