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XQSHEN's avatar
XQSHEN
Icon for Occasional Contributor rankOccasional Contributor
3 years ago

problem using altmemphy to read ddr2

Device: EP4CE22F17C8

Memeory: Micron MT47H64M8CB-3

IP: altmemphy DDR2

Burst count = 16

I met a problem to read out data using altmemphy.

1) if I start with write operation ddr2 at first, after finished; then try to read data out of memory, then I can never get the data, the local_rdata_valid is always low.

2) if I don't do any write operation, try to read the data out of memory, I can get it successfully.

I don't see any problem with my write process.

What's wrong?

Picture : write + read

Picture only read

2 Replies

  • AdzimZM_Altera's avatar
    AdzimZM_Altera
    Icon for Regular Contributor rankRegular Contributor
    3 years ago

    Hello,


    Did the calibration finished properly in the design?

    What is the test_start signal does?

    Is there a waitrequest signal in your design?

    How do you perform the write and read transaction?


    Thanks,

    Adzim


  • AdzimZM_Altera's avatar
    AdzimZM_Altera
    Icon for Regular Contributor rankRegular Contributor
    3 years ago

    We do not receive any response from you to the previous question/reply/answer that I have provided. This thread will be transitioned to community support. If you have a new question, feel free to open a new thread to get the support from Intel experts. Otherwise, the community users will continue to help you on this thread. Thank you.