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Altera_Forum's avatar
Altera_Forum
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21 years ago

NIOS SDRAM performance

I have measured the speed of memcpy's of NIOS2. I use optimized code consisting of four consecutive READs and four consecutive write accesses. Code snippet: while (i--) { d0 = __built...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
21 years ago

If I read Jesse right, the problem is in Nios' Data Master. It is not "Latency Aware" meaning it does not monitor 'readdatavalid'.

Soooo, with only static timing at it's disposal, the Data Master must use the same absolute worst case timing for each and every read.

Privately I've been shown that read performance is still a dismal 5-6 clocks from initial access to 'readdatavalid' even when accessing the same row back to back.

I&#39;d really like someone to explain the "single cycle access" statements that are given in Nios classes and docs. Better yet, make the statements come true http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/smile.gif

Ken