2 Replies Latest reply on Oct 29, 2015 12:20 PM by userc_17331

    Why BLE Chip BCM20737 may reset periodically?


      I am observing a very strange thing about the BLE chip BCM20737. After I power up this chip, it may reset every 3~4 minutes. I have recorded the debug traces, and I can see "Application Up" from debug trace every 3~4 minutes. I will print "Application Up" in app_Create function, which is registered in APPLICATION_INIT(). So this debug info should only appear once when the application starts up.


      Here is the code:

      static void bleptu_Create(void)


          // some codes ...

          ble_trace0("Application Up");







                        (void *)&bleptu_cfg,

                        (void *)&bleptu_puart_cfg,

                        (void *)&bleptu_gpio_cfg,



      More information:

      1. I also use an oscilloscope to probe at the reset pin of BLE 20737 chip, the reset pin is always pulled-up to high and very stable.

      2. The BLE chip is BCM20737, not BCM20737S.

      3. I have disabled sleep mode by adding the following code:

      register in app_Create function.

      devlpm_registerForLowPowerQueries(DeviceLPMQueriable, 0);

      always return 0 to disable sleep mode

      static UINT32 DeviceLPMQueriable(LowPowerModePollType type, UINT32 context)


        // disable sleep

        return 0;


      4. I also see one sentence "CSA Filter Disable" before "Application Up". What does "CSA Filter" mean? I didn't add anything about it in my code. Does it relate with the reset issue?

      If you have any ideas about this issue, I'd really appreciate your help.

      Thank you


        • 1. Re: Why BLE Chip BCM20737 may reset periodically?

          Hello userc_17331


          1.  Are you sending characters over PUART?

          2.  You will receive our CSA Filter Disable message since Our ROM will disable this if you send this sequence of bytes.

          3.  If the device gets a "D" for delta it will disable the App

          4.  You should be looking at the sample App A4WP PTU sample App.




          • 2. Re: Why BLE Chip BCM20737 may reset periodically?

            For your information,

            1. I am not using PUART.

            2. CSA Filter seems to have nothing to do with the reset issue.

            3. What do you mean by "D" for delta?

            4. I have tried A4WP ptu sample app, will reset every serval minutes periodically as well.


            One more thing I found these days.

            If I use BLE_APP_DISABLE_TRACING() to disable debug trace, even though debug trace is disabled, the reset issue may still happen.

            However, if I set bleapp_trace_enable = 1; the reset issue disappears. (And debug trace is disabled)


            Any clue on why this reset issue happens?