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Altera_Forum's avatar
Altera_Forum
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14 years ago

Urgent: Different timing analysis result for DMA

Hello, I did a timing analysis for DMA to transfer 2MB of data. The first time i executed it, using DMA, the system improved by 88.75%. When I ran it for 2nd time, the performance became 48.5% only. why the performance will decrease from 88.75% to 48.5%? I did not change the code or the core.

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Do you run it twice in a row from the same software, do you re-upload a new software between the two tests, or are you reconfiguring the FPGA and upload the software between the two tests?

    You should put some Signaltap probes on the DMA's master to see if anything different is happening during the tests.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    14 years ago

    Yeah, it is correct now. I did a mistake by adding some function in DMA part. Thanks!