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Altera_Forum's avatar
Altera_Forum
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11 years ago

Odd nios2-download verify fail between address issue, on-chip memory

Hi,

I have been running into a odd nios2-download verify failure issue.

I was trying to test the impact of different cache size of nios proceossr. However, when I change the cache size to some certain values, I started getting "Verify failed between address 0xXXXXXX and 0xXXXXXXX" issue. The address is for the on-chip memory. Some cache size setting still works fine...

Having been going through many threads in the forum but no luck yet... Have anyone got similar things before?

Thanks in advance!

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    11 years ago

    xxiang, are you using an SDC file and checking for timing closure?

    If you raise the cache size too much it's possible that timing won't be met because internal memory is already placed on the device, and routing to all the memory blocks needed for your processor cache may decrease the Fmax of your processor and system.

    Timing problems may lead to "verify failed" errors.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    11 years ago

    Thanks for your reply vtoffolo. I did check timing. There were some tiny timing violation (~0.04ns) but those were not in the nios processor, I assume that shouldn't cause the problem. However, the error is gone now with a new build, for no reason...

    --- Quote Start ---

    xxiang, are you using an SDC file and checking for timing closure?

    If you raise the cache size too much it's possible that timing won't be met because internal memory is already placed on the device, and routing to all the memory blocks needed for your processor cache may decrease the Fmax of your processor and system.

    Timing problems may lead to "verify failed" errors.

    --- Quote End ---