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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

IIRC (from other posts here) even alt_uncached_malloc() isn't guaranteed to return memory that doesn't share a cache line with other malloced memory (or the malloc systems red-tape), nor does it ensure the cache doesn't already contain data for the address range (which might be written out later).

Using globals would work - provided you mark them with __attribute__((aligned,32)) assuming 32 byte cache lines.