2 Replies Latest reply on Aug 23, 2016 9:53 AM by kelly.lindseth

    PMODE pins on FX3

    kelly.lindseth

      I do not understand the PMODE table that defines pins as being 0,1, or Hi Z.  If a pin is Hi Z, it can be 0 or 1 so that results in entries to the table starting to double up.  If my goal is USB boot, the entry is Z11, which equals 111 or 011 and corresponds to I2C only, I2C with USB on retry, SPI with USB retry, possibly others. 

         

      Does cypress mean for you to drive 0 and 1 hard with no pullup or pulldown resistor allowed and then complete disconnect for the Hi Z case?

         

      I could see that such a scheme would allow you to test for the HiZ by reading it and then weakly pulling it to the opposite value and reading it again.