11 Replies Latest reply on Apr 1, 2020 3:49 AM by HemanthR_06

    SuperSpeed Design Examples V1.2.1 GPIF examples

    lopo_1264666

      From "SuperSpeed Design Examples V1.2.1" and with CollectData set to "File To Receive".

       

      Using Counter1.xsvf and defaulted GPIF clock (80MHz) for GPIF_Example1, found out that the gap = 56 forever using CheckData for File Transfer TimeOut = 20s. Next, I used command “PCLK-“ to reduce the GPIF clock to 50MHz and the gap reduced to 40 forever for File Transfer TimeOut = 20s.

       

      Using Counter1.xsvf and defaulted GPIF clock (80MHz) for GPIF_Example2, found out that the gap alternates between these 2 values: 8192 and -8192 using CheckData for File Transfer TimeOut = 20s. Next, I used command “PCLK-“ to reduce the GPIF clock to 50MHz and the gap changed to -1 forever for File Transfer TimeOut = 20s.

      Since gap = -1 represents perfect case where host computer can keep up with the counter count in CPLD while gap = positive number means missing counter count, how about -8192?

       

      I don’t really understand the last statement returned by CheckData. TotalMissedSamples = summation of all gap values? How about the percentage analysis such as 2%, 1160%? I tried to plug in the numbers but couldn’t get its value correctly. Please refer to my attachment.