2 Replies Latest reply on Nov 13, 2017 8:34 AM by MoAb_1070241

    Bus width setup when using AN75779 Application Note


      I have looked at the AN75779 Application Note, and there is some confusion over the bus width setup, as explained below:

      The GPIF II interface is setup for an 8-bit data bus, but the uvc.c code shows the IO Matrix being setup as shown below:


      /* Configure the IO matrix for the device. */

      io_cfg.isDQ32Bit        = CyTrue;

      io_cfg.s0Mode          = CyFalse;

      io_cfg.s1Mode            = CyFalse;

      io_cfg.lppMode          = CY_U3P_IO_MATRIX_LPP_DEFAULT;

      io_cfg.gpioSimpleEn[0]  = 0;

      io_cfg.gpioSimpleEn[1]  = 0;

      io_cfg.gpioComplexEn[0] = 0;

      io_cfg.gpioComplexEn[1] = 0;

      io_cfg.useUart          = CyTrue;   /* Uart is enabled for logging. */

      io_cfg.useI2C           = CyTrue;   /* I2C is used for the sensor interface. */

      io_cfg.useI2S           = CyFalse;

          io_cfg.useSpi           = CyFalse;


      Why is isDQ32Bit set to CyTrue when the GPIF II interface is setup for 8-bit? I am guessing that the setting in io_cfg is somewhat disjoint from the GPIF II setup in that one can set the isDQ32Bit to “true” and use any allowable data bus width within GPIF II. Could someone shed some light on this for me?