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LPC2148 software reset

joao martins

Hi

How can I make a software reset at LPC21xx family processors?

thanks,
joao

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  • 0

    Hi,

    best way I know is using the watchdog timer.
    Basically the procedure is like that:
    After power on reset, during initializations you check a certain area in memory (SRAM) for a predefined key.
    If you did not find it because after a power on reset this is supposed to be random, you decide that this was NOT a soft reset. No you initialize this area of memory with a value that indicates a "real watchdog reset"
    Before you go into the softreset, you overwrite this word in memory with a value representing the "softreset".
    You will get a reset, and you will go back to the checking after reset.
    In case this seems a little confusing, let me know and ask specific questions.

    Hope this helps, regards, Robert

    Reset
    |
    check for magic value
    |
    Does value represent predifined reset?
    |
    If yes, it was a "real wdt" or a "softreset"
    |
    If no, it was a power on reset
    |
    Initialize for "real WDT reset"
    |
    Before you go in to soft reset
    initialize for soft reset
    |
    set WDT to minimum and do not service it

Reply
  • 0

    Hi,

    best way I know is using the watchdog timer.
    Basically the procedure is like that:
    After power on reset, during initializations you check a certain area in memory (SRAM) for a predefined key.
    If you did not find it because after a power on reset this is supposed to be random, you decide that this was NOT a soft reset. No you initialize this area of memory with a value that indicates a "real watchdog reset"
    Before you go into the softreset, you overwrite this word in memory with a value representing the "softreset".
    You will get a reset, and you will go back to the checking after reset.
    In case this seems a little confusing, let me know and ask specific questions.

    Hope this helps, regards, Robert

    Reset
    |
    check for magic value
    |
    Does value represent predifined reset?
    |
    If yes, it was a "real wdt" or a "softreset"
    |
    If no, it was a power on reset
    |
    Initialize for "real WDT reset"
    |
    Before you go in to soft reset
    initialize for soft reset
    |
    set WDT to minimum and do not service it

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