4 Replies Latest reply on Aug 31, 2010 3:48 PM by doug.sandru

    Using capture from an external clock to wake-up device

    doug.sandru

      Using the CY8C24423A I am trying to use the falling edge of a pulse to wake-up the device, do some ADC, then go back to sleep... wake up on the next falling edge etc and repeat....     

       

         

      I read in the Cypress Datasheet for my part that the system can only wake up from: GPIO Ints, supply mon. int., analog column int, and timer clocked EXTERNALLY or from 32KHz clock.     

       

         

      My timer that I am using is clocked from the incoming pulse train (variable)... I have a hardware reset that causes a GPIO interrupt and I have seen that work by toggling an LED (sleep and non-sleep), but whenever I put the device to sleep and expect to see the LED go high on the falling edges of the incomming pulse it's not there. When I don't put the system to sleep I can see my LED go high as expected...     

       

         

      Is what I am doing possible? I'm not sure if there is some assembly I might have to change to make this work... has anyone else had to do something similar?     

       

         

      I haven’t been real specific in my application, except that I need to do ADC on the low portion of a pulse and then go back to sleep. Maybe there is a better way to do this…     

       

         

      Any help will be appreciated.