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Altera_Forum's avatar
Altera_Forum
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9 years ago

Disable caching for some memory parts

Hi I have a TCP/IP stack running on my NIOS. The big part of the data goes directly from the FPGA-HW to a DDR3 memory, the stack has only to add some addresses etc. Is it somehow possible to...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
9 years ago

You shouldn't be flushing the entire dcache before doing DMA. There are routines that I have forgotten the name of that will flush only a given area. I don't recommend setting your DMA buffers to be uncached as that will slow down CPU access to that area. After doing a DMA read, invalidate the buffer. Before doing a DMA write, flush the buffer.