3 Replies Latest reply on Aug 22, 2012 5:57 AM by user_14586677

    psoc1 hanging

    geethu.krishnan

      I am using the cy8c20546-24pvxi for touch sensing on my keyboard. even after implementing a Watchdog my psoc is hanging at unpredictable times. Kindly leme know asap what the issue can be. Is thr any possibility that the watchdog timer also hangs if the internal ILO/IMO hangs? It is urgent. Expecting a reply asap.

         

      Gee

        • 1. Re: psoc1 hanging
          arvi

           Gee,

             

           

             

          I'm not sure how the ILO/IMO can "hang". Perhaps you can elaborate on the problem or if possible attach the project.

             

          It will help us understand the issue better.

             

           

             

           

             

          Regards,

             

          Arvind

          • 2. Re: psoc1 hanging
            user_14586677

            Unexpected behaviour can come from a number of sources -

               

             

               

            1) Code based.

               

            2) Transient voltages outside specification limits.

               

            3) External clock hiccups.

               

            4) System noise.

               

             

               

            Tracking down -

               

             

               

            1) For code based errors, disable specific modules of code, one at a time, and see if problem

               

            disappears. Plant a heartbeat monitor in sections of code, a pulsing led, and look for any module

               

            that stays active after the hang, knowing whats running can also be a clue.

               

             

               

            2) Set a scope up, DC trigger, and look for pin violations interfaced to externals. Same with

               

            Vdd. If you get a trigger, say set for 6V on Vdd, or - 1 V on a pin, find the source and cure.

               

             

               

            3) Using a scope, if external clock, set scope trigger for runt pulse detection. Also use scope

               

            on xtal pins (FET probe) and look for voltage violations as discussed earlier.

               

             

               

            4) Use a scope on infinite persistence and look at external pins, Vdd, Vss, for excessive

               

            noise.

               

             

               

            Just some suggestions, regards, Dana.

            • 3. Re: psoc1 hanging
              user_14586677

              Of course a keyboard is a classic static problem environment.

                 

               

                 

              Scope again set to trigger on V or T violations a big help. Note scopes can also be triggered

                 

              on pattern violations for multi channel scopes.

                 

               

                 

              Regards, Dana.