32-bit GPIF Interface failing at 100 MHz - KBA84082

Version 1
    Version: **


    Question: Why does the 32-bit GPIF interface fail at 100 MHz?



    There are several possible reasons:

    1.   When you call the CyU3PGpifSocketConfigure() API, the ‘burst’ parameter must be greater than 0.
    2.   If you are using the internal clock, the clkDiv parameter of pibclock must be set to 4.The default value in SDK is 2.
    3.   Make sure the setSysClk400 parameter is set. The FX3 master clock is set to 384 MHz by default when you use a 19.2 MHz crystal or clock source. This frequency setting may lead to DMA overflow if the GPIF is configured as 32-bit wide and running at 100 MHz. Setting this parameter will switch the master clock frequency to 403.2 MHz during the CyU3PDeviceInit() call.
    4.   The following code must be in main () to initialize the device


         CyU3PIoMatrixConfig_t io_cfg;
         CyU3PReturnStatus_t status = CY_U3P_SUCCESS;
         CyU3PSysClockConfig_t clkCfg = {
         2, 2, 2,
         /* Initialize the device */
         status = CyU3PDeviceInit (&clkCfg);
         if (status != CY_U3P_SUCCESS)
         goto handle_fatal_error;