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Altera_Forum
Honored Contributor I
807 Views

Who have the code of Scatter-Gather DMA?

I meet a lot of problems of Scatter-Gather DMA,i do not have the example of Scatter-Gather DMA.it is very hard to make it.some one who have the code of Scatter-Gather DMA please upload it. 

thanks in advance
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5 Replies
Altera_Forum
Honored Contributor I
73 Views

Here you go: http://www.altera.com/support/examples/nios2/exm-scatter-gather-dma.html 

 

There will be a new "Modular SGDMA" that will be posted up on the Nios II design examples page shortly. It doesn't use descriptor fetching and as a result is much easier to use in my opinion. If you want to take a look at it send me a message with your email address and I'll forward it to you. This is the Modular SGDMA feature list that isn't present in the SGDMA today: 

 

  • Up to 4GB transfer lengths 

  • ST-->MM early termination (packet length limiting) 

  • Interrupts per descriptor 

  • MM-->ST error signal 

  • Burst boundary re-alignment 

  • Park mode built into the descriptor (makes frame buffering easy) 

  • Descriptor sequence numbering (tag the descriptors then readback from the SGDMA to find out which descriptor the read and write masters are working on) 

  • Descriptor programmable burst 

  • Descriptor stride (address increment for fixed/interleaved data) 

  • Data widths up to 1024 bits 

  • Independent reads and writes (i.e. descriptors are dual buffered so the write master does not block the read master from starting up again) 

  • Burst lengths up to 1024 beats 

  • User selectable data/descriptor FIFO depths
-JCJB
Altera_Forum
Honored Contributor I
73 Views

thank you for your suggestion,but i want to learn the descriptor to control the SGDMA,so i wish you give me an example of the SGDAM. 

my mailbox address is: 

li_polaris_1988@yahoo.cn 

thank you very much
Altera_Forum
Honored Contributor I
73 Views

this link is not available. please re-update link.

Altera_Forum
Honored Contributor I
73 Views

It was moved to the alterawiki. If you search for "modular SGDMA" on the wiki it should bring you to the correct page.

Altera_Forum
Honored Contributor I
73 Views

Thank you so much.

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