1 2 Previous Next 18 Replies Latest reply on Jul 9, 2012 7:01 AM by lehua.chen

    Maximal PCLK frequency in Slave FIFO Sychronous


      Hello, I try to supply the PLCK with 80MHz sine wave. When I click Transfer Data-In in USB control center, at the first several times, the transfers are correct. Then it will show “BULK IN transfer failed with Error Code: 997”. It does not happen when the PCLK frequency is below 50MHz (throughput: 136MB/s).

          My setting is as following:   
          epCfg.burstLen = 15;   
          dmaCfg.size = size*15;     
          0x07,  /* Max no. of packets in a burst   
          My questions are:   
          (1), Is it possible to supply PLCK with sine wave at maximum frequency (eg: 80MHz)? It seems the sine wave is the same as square wave as a clock, because only the rising edge is used.   
          (2), In the manual, it mentions “programmable 100-MHz GPIF II interface”. What is the maximal throughput if PCLK is 100MHz. How should we set the burstLen, dmaCfg.size and Max no. of packets in a burst?   
          (3), In the Readme.txt in USB BULK SOURCE SINK EXAMPLE, Having only 1 endpoint (IN or OUT) is recommended. So if I only want to use Endpoint In, is it necessary to delete endpoint OUT?   
          Best regards,   
          Lehua Chen   
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