3 Replies Latest reply on Nov 7, 2017 4:12 AM by samp

    If SCL and SDA are left floating, can latchup occur

    sean.gilmour_2849506

      Hi There,

       

      I am reviewing a CY8C2123 design. There appears to be a latchup problem. There are 2 issues I can see;

      (1) When programming, there is an edge connector on the PCB to plug in a programmer. This edge connector connects power, ground and I2C lines and programs the device. The ground pin on this port is not longer than the others so ground may not be connected first. If the programmer is plugged in and powered up, can this cause latchup?

      (2) Once the programmer is removed, the pullups for the I2C bus are removed (there are none on the board). When the device powers up in operational mode, there are no pullups on the data or clock lines. can this cause problems?

       

      Any help appreciated.