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LCD Message “fixed BOR setup”

  • From the forum:

The BOR feature is a brown-out reset, which resets the core if Vdd is too low.

  • From the Change Log:

The “Brown Out Reset” (BOR) settings in the configuration sector are changed automatically when MIOS detects unproper settings - the appr. cell in this sector will be overwritten and the device will be reset.

New Setting: Brown Out Reset at 4.5V

This ensures that the PIC won't access devices during power-off which cannot operate at voltages < 4.5V (e.g. the Bankstick, which could get an unintended write command)

  • From the forum:

The LCD message you saw notifies about the activation of the BOR flag, see documentation in the Change Log: - this is no error message, but just a hint, that this (required!) change has been done.

So, what could happen: your PSU is too weak, or there is a short circuit somewhere, which drops the core voltage to below 4.5V. At this voltage some external components (like LCDs or banksticks) don't work reliable anymore, therefore the PIC is forced into reset state, so that nothing “dangerous” happens (e.g. so that the bankstick format routine won't be started). Probably for your application the BOR reset is not really relevant, but in general it makes sense to activate it.

So - my tip - remove all 74HC595 chips and check if the reset still happens. The successively put them into the sockets again (switch-off the power when doing this!) in order to find out, which part of the DOUT chain is defective.
If this doesn't help, disconnect the whole DOUT chain from the core module in order to find out, if the short-circuit is there, or anywhere else.

Best Regards, Thorsten.

fixed_bor_setup.txt · Last modified: 2006/10/15 09:35 (external edit)