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WDTCN disable

Hello,
I have a AT89C5131 development kit and I want do disable the WDTCN (watchdog timer) but in the list of the registers in the file "at89c5131.h" it looks like there are two registers:
Sfr ( WDTRST, 0xA6 ) ;
Sfr ( WDTPRG, 0xA7 ) ;

What do I need to do in order to Disable the watchdog timer.

Thanks!

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  • Have you still not taken the time to read the first section of the datasheet? The part where they say that the watchdog can't be disabled after having been started - except by resetting the processor.

    You really haven't much progress with datasheets...

  • I read it. I would be glad if you stop trying to fight me. Its my first time using this microcontroller and its strange that I cant disable it from the beggining of the program.
    Have a good day!

  • So all the more reason why you need to really spend time thoroughly studying the datasheet!!

    "its strange that I cant disable it from the beggining of the program"

    Is that what the datasheet actually says?

    Chips function in accordance with what's stated in their datasheet - not the way you think you'd like them to behave!

    Sometimes, the way a chip behaves (as stated in its datasheet) will not be suitable to your specific requirements - so you either need to select another chip, or revise your approach...

  • Well, its not my choice to use this microcontroller. If you have a correct answer that can help me I will be happy to listen to you.

  • Again, the answers you require are clearly stated in the Datasheet - read it carefully and thoroughly.

    "its not my choice to use this microcontroller"

    So have you discussed this with whoever assigned you this project?

  • Specifically, the section titled, "Hardware Watchdog Timer"

  • "I would be glad if you stop trying to fight me."

    I fight you because you seem so totally uninterested in what I'm trying to say.

    I asked you if you had verified that you had the correct datasheet. You answered with a "of course" about the header file - so no response about the datasheet. That lost you time.

    When you finally had the correct datasheet (you never told us what datasheet had only one register and with a different name) I asked you if you had read the first section about the watchdog - it contained all you needed to know: that you can't stop an already started watchdog without resetting the chip. That lost you time.

    It also explained that the chip boots with the watchdog off - so no need to stop a watchdog that has never been started.

    It is common that a watchdog has no means to disable - a broken program must not accidentaly find any sequence that turns off the WD protection.

    If you want any progress, you really have to start reading the datasheet information. Ask if you don't understand some text, but don't expect others to read the datasheet for you. 5 minutes reading the WD chapter and you would have saved a huge amount of time. But maybe you are in a hurry and doesn't have the time to save some time...

  • any good watchdog can not be disabled once it is enabled.

    were that possible, a "wild write" could disable the watchdog, which would defeat the purpose of having one.

    Erik

  • I have never witnessed the problem before.

  • Again, what "problem" are you talking about?

    Or is it just that you turn a blind eye to all problems...?

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