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Altera_Forum
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13 years ago

Data stream to PCIe: regular or scatter gather DMA controller?

For a simple data flow (FIFO output to DMA controller to PCIe TXS port) is there any advantage to using the scatter/gather DMA controller rather than the regular DMA controller? There is only one ...
Altera_Forum's avatar
Altera_Forum
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13 years ago

The main advantages of the scatter/gather DMA are that you can chain several DMA commands with no software intervention, and that the DMA core can be connected to Avalon Stream sources and sinks, so it can be interfaced with FIFOs and components more easily (IIRC the regular DMA can only do memory to memory transfers).

IF you don't need those two features then the regular DMA is probably simpler to use.

There is also a modular sgdma (http://www.alterawiki.com/wiki/modular_sgdma) component available on the wiki that I think is easier to use than the SGDMA. But I haven't tried it.