1 Reply Latest reply on Jul 10, 2019 8:46 PM by RashiV_61

    How to change data bus witdth from 32bit to 16bit


      Hello to everyone, I have a problem with the data bus of my FX3 - FPGA (Altera Cyclone 5) slave FIFO interface.

      I used a custom firmware derived from AN65974 and continuouos read project but I need to change the data bus width from 32 to 16 bit.

      I tried to edit this part of the cyfxgpif2config.h but it didn't work, when I try to transfer data with the cypress control center app the bus remains at 32bit.

      This is the edited part :


      /* Summary

         GPIF II configuration register values.


      uint32_t CyFxGpifRegValue[]  = {

      0x80000780,  /*  CY_U3P_PIB_GPIF_CONFIG */

      //    0x000000AC,  /*  CY_U3P_PIB_GPIF_BUS_CONFIG */

      0x00000067,  /*  CY_U3P_PIB_GPIF_BUS_CONFIG */    // changed to 16 bit from 32 (0xAC)

      0x07000001,  /*  CY_U3P_PIB_GPIF_BUS_CONFIG2 */

      0x00000046,  /*  CY_U3P_PIB_GPIF_AD_CONFIG */


      The question is: Do I have to edit other registers to changhe the data bus width?

      thanks in advance



        • 1. Re: How to change data bus witdth from 32bit to 16bit



          Here are the steps:

          1.Open the GPIF project provided with AN65974.

          2.Select 16 bit as Data Bus width in the Interface settings. (GPIF Designer Tool)

          3.Save it and build the project by clicking Build > Build Project to generate the cyfxgpif2config.h file.

          4.Set CY_FX_SLFIFO_GPIF_16_32BIT_CONF_SELECT to ‘0’ in the cyfxslfifosync.h file.

          5.Build the project. This step generates the image file for the 16-bit Slavefifo application.




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