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Honored Contributor
Honored ContributorMax 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_ForumHonored Contributor
Honored ContributorYou should be able to hit around 97% (max) efficiency using a SGDMA depending on the access pattern. I recommend using the HP2 or Uniphy controllers since they don't need burst accesses to be efficient. If you access them sequentially then internally they'll form optimal offchip bursts for you.
If you want to continue using bursting I highly recommend that you match the burst counts of the DMAs to the memory to avoid burst adaptation. You might also run into burst wrapping efficiency problems as well since the DMAs don't line themselves up on burst boundaries except this one: http://www.altera.com/support/examples/nios2/exm-modular-scatter-gather-dma.html?gsa_pos=1&wt.oss_r=1&wt.oss=sgdma
