1 Reply Latest reply on Jun 17, 2015 8:17 PM by user_14586677

    FreezeIo issue

    user_343349849

       I have a low power application that is drawing too much current when connected to another IC and placed into Deep Sleep.

         

      If I measure current of each IC independently, the micro is drawing 19uA and the other IC 8uA when in deep sleep.

         

      If I have both powered together (even though the interface pins are not active), the current jumps by additional 50uA.

         

      When I issue CySysPmFreezeIo() before deep cleep, the current drops right down below 19uA with both ICs connected. But, the circuit does not operate correctly and if I attempt to debug then I loose coms with MiniProg 3 when freezing the IO.

         

      It appears when the the IO is frozen, it now longer gets woken from Deep Sleep (I am using an IO pin to wake from sleep).

         

      I copied the IO freeze example from the PSCOC4200 GPIO document.

         

      Do I need to add a delay or something after Unfreeze before using the pins? 

         

      Also, I have set the IO pins to High Impedance Digital for inputs and Pull Down Resistive for outputs, I assume this is the lowest current option ?

         

      BTW: I am not worried about powered up current as it only operates for less than 100ms and back to sleep, it is the deep sleep current I want to reduce.

         

      Thanks