2 Replies Latest reply on Mar 22, 2018 8:56 AM by bob.marlowe

    MISO pin behaving abruptly during SPI communication

    user_418894472

      Hi!

      I have a project in which an SPI master sends four continuous bytes of data to an SPI slave. All four bytes are transferred in one-go without releasing the SS pin. The SS pin is released high after all four bytes are transferred.

      The input from the ,master is received correctly by the slave via MOSI pin. However the MISO pin gets glued to high position randomly and corrupts the slave output data. It also appears that the MISO pin goes to high impedance after the SS pin is released. (MISO output voltage slowly ramps down to 0V from initial 5V when SS pin is released)

       

      (Blue = MISO. Yellow = SS)

      Please help