Forum Discussion

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

Max throughput of SOPC DMA?

Hello, Currently I have a system with DMA transfers and DDR2 SDRAM (and a lot of other stuff). I'm using the normal SOPC builder DMA controller. I run the system on 100 MHz, the DDR2 SDRAM run...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

I don't use bursting at the moment no, because I haven't enabled that. When I tried to use bursting a while back it didn't seem to work, but I can try that again. Since it was most likely due a software fault.

The max amount I can burst at one time is 1024 words (if the DDR2 can handle that) . So that indeed means I would have to set up 8192 DMA transfers if I wanted to transfer 32 megabyte.

I did try using two seperate on-chip memories though for communicating with the Serial RapidIO core (again non bursting):

[On-chip TX_data] -> Serial RapidIO Core loopback -> [On-chip RX_data]

and I get a whopping speed of 8.2203 megabyte/second.

With the following set-up:

[DDR memory_1] -> Serial RapidIO Core loopback -> [DDR memory_1]

I got a speed of 4,9936 megabyte/second

Maybe I should use bursting for the entire system then (since the Serial RapidIO Core supports it). Since you are saying these kinds of speed aren't normal.