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Altera_Forum
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12 years ago

Tightly Coupled OnChip DMA

Hi, I've got some very strange 'performance behavior' with a tightly coupled on chip memory used as data storage. In order to speed up my design, I've created a tightly coupled on chip memory w...
Altera_Forum's avatar
Altera_Forum
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12 years ago

Got back on working on that issue yesterday, and it seems that by moving heap & stack and also the code to respective TCM coupled onchip memories resolve the contention on the bus.

One small question related to that whole issue: My algorithm heavily relies on memory accesses and I measured with a performance counter that my algorithm takes ~ 30 000 000 clock cycles. Doing a naive calculation this should roughly translate to 300ms, but measuring with a interval timer I see ~1200 ms now. Does anyone have good guess why the two methods differ that much? Or even better, has anyone a good advice on how to increase the utilization of the NIOS?

Thanks for all the help so far.