5 Replies Latest reply on Aug 2, 2020 12:18 AM by GaneshD_41

    PSoC5LP MCU freeze

    HaIn_1319421

      We have developed a data logger based on PSoC5LP, external 32KHz RTC crystal, that spends most of it's time in SLEEP mode (1sec RTC interrupt enabled, short LED status blink). On rare occasions the device freezes, the RTC interrupt stops (no LED status blink). The 32KHz crystal is still running. The only escape out of this condition is a hardware reset.

      Q1) Is there a way for us to examine the status of the IMO/PLL/Master & Bus Clocks?

      Q2) An External 10 minute Watchdog might solve our problem. What circuit do you recommend for such an external device?

        • 1. Re: PSoC5LP MCU freeze
          GaneshD_41

          Hi,

           

          1. You can route a clock to the GPIO pins and check if the Clocks are running fine.

          2. You can also use the Watchdog timer internal to PSoC Creator to reset the device after a time-out if the watchdog interrupt is not cleared.

          3. You can also find an external watchdog that can support your long time.   There are a chip type called a SBC (System Basis Chip) that include many system subfunctions like a Voltage Regulator some higher voltage IO control and an external watchdog.

           

          But before trying above points identify the reason for system to get stuck. From the description I think the device is going to latch-up state frequently. If this is the case watchdog timer will not help. Only a power-on reset/XRES reset will get the device out of it. The main reason for device going into the Latch-up state is improper grounding in the Layout or noise spikes in the power supply.

           

          Kindly attach your board files(schematic and gerber files of Layout) and your project too.

           

          Thanks

          Ganesh

          1 of 1 people found this helpful
          • 2. Re: PSoC5LP MCU freeze
            HaIn_1319421

            Hello Ganesh, thanks for your prompt reply, it gives us some good points to look into.

             

            I forgot to mention that ours is a very low-volume project that does not justify a dedicated PCB. We simply use the CY8KIT-059 Prototyping board as the core, so I doubt that a PCB design flaw around the PSoC5LP chip is the problem. The problem is most likely caused by something in our surrounding circuitry.

             

            Our problem is that these lock-ups are very rare, we have never been able to duplicate them and thus been unable to nail them down.

             

            Best reegards

            Halfdan

            • 3. Re: PSoC5LP MCU freeze
              GaneshD_41

              Hi,

               

              >>"We simply use the CY8KIT-059 Prototyping board as the core"

              --> Okay. So there will not be any issues at the board side.

               

              Can you please send us the images of your complete setup?

              Can you please explain more about your power supply?

               

              Thanks and regards

              Ganesh

              • 4. Re: PSoC5LP MCU freeze
                HaIn_1319421

                I am currently on a road trip, taking the opportunity given by COVID to re-visit a mostly tourist-free Iceland. I will be back with you next week.

                 

                Our power supply is 4 parallell-connected 18650 Li-Ion cells, which we consider a solid power source.

                • 5. Re: PSoC5LP MCU freeze
                  GaneshD_41

                  Hi,

                   

                  >>"Our power supply is 4 parallell-connected 18650 Li-Ion cells, which we consider a solid power source."

                  --> Okay.

                   

                  Please share your PSoC Creator project, images of your board, schematic (if any).

                   

                  Happy vacation !!

                  Thanks

                  Ganesh