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UCD90124A: Software watchdog disable/enable

Part Number: UCD90124A

We have a UCD90124A in our system and need to be able to disable/enable the watchdog timer from software while the system is running without resetting.  We assumed we could write the  (D3h) SYSTEM_WATCHDOG_CONFIG command with the enable bit 7 in byte 2 set to zero but that doesn't seem to be working.  We tried running just the config command and also tried running the config command followed by issuing a watchdog 'tickle', neither seemed to have an effect.

Is there something special that needs to be done to get the watchdog disabled?  Do you have a code example we could try?

  • Hi

    Please toggle the highlighted bit to enable/disable watchdog.

    Regards

    Yihe

  • Looking at the description of the bit in the Command Reference (SLVU352G) it says:

    10.4.4 Disable Until System Reset Release

    When this bit is set, the System Watchdog Reset function will be temporarily disabled until the System Reset pin is de-asserted. This temporarily disabled state only applies when the device comes out of reset or when the System Watchdog Reset command is written.

    We use an active low reset.  When it says de-asserted is it talking about an edge (rising edge) or a level (high)?

    The first sentence seems to imply the bit will take effect immediately, the second sentence says we need to issue a watchdog reset command after setting this bit for it to take effect.  Which interpretation is correct?

  • Hi

    System reset and system watchdog reset are two different functions. 

    as long as you are not using system reset function, what proposed in the previous reply is good,

    You have to write wait system watchdog command to toggle that particular bit

    Please try and report it back.

    Regards

    Yihe

  • We are using both watchdog and system reset function.  I asked our s/w engineer to try and report back.