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Bob_Yang's avatar
Bob_Yang
Icon for New Contributor rankNew Contributor
7 years ago

The output from the LPM counter get unexpected values.

I encounter a tricky problem during doing my project. Following is the diagram for the stopwatch_v2, the problem is the counter increases by more than 1 per second (the number output from the counter is 0, 5, 10, 15...), it should increase by 1 per second. I did something wrong? Thanks!

Following are the diagram and VHDL code of LPM_Counter_4Bit:

6 Replies

  • KhaiChein_Y_Intel's avatar
    KhaiChein_Y_Intel
    Icon for Regular Contributor rankRegular Contributor

    Hi,

    What simulation tool you are using? I couldn't find the testbench file in the design. Could you share the steps?

    Thanks.

  • Bob_Yang's avatar
    Bob_Yang
    Icon for New Contributor rankNew Contributor

    Hi, the outcome of simulation is correct. I encounter this issue as long as I run it on the board.

  • KhaiChein_Y_Intel's avatar
    KhaiChein_Y_Intel
    Icon for Regular Contributor rankRegular Contributor

    Hi,

    The simulation ensures the correct functionality of the logic in the design. Upon checking, the design has both setup and hold timing violation. I could not find any sdc file in the project. You have to specify initial timing constraints that describe the clock characteristics, timing exceptions, and signal transition arrival and required times. When your design is free of timing violations, you can be confident that the logic will operate as intended in the target device.

    You may refer to https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/manual/mnl_timequest_cookbook.pdf for the SDC constraints

    Thanks.