On Mon, Oct 10, 2011 at 4:00 PM, IB Peter Feucht <feuchts@kabelbw.de> wrote=
:
> Now the 684 has an brown out reset, which is pricipally doing what I want=
,
> but I see no possibility to distict between a "cold boot reset" (made whe=
n
> e.g. batteries are changed) and brown out reset.
> In case of a cold boot reset the devide should work normally, but when a
> brownout occured, I'd like to simply disable any further operation until =
new
> batteries are inserted.
>
> Does anybody have an idea, know of any sort of "hidden features", any sor=
t
> of dirty tricks to make this?
>

http://ww1.microchip.com/downloads/en/DeviceDoc/41202F-print.pdf
Section 12.3.7, Power Control (PCON) Register

The Power Control register PCON (address 8Eh) has
two Status bits to indicate what type of Reset occurred last.

Bit 0 is BOR (Brown-out). BOR is unknown on
Power-on Reset. It must then be set by the user and
checked on subsequent Resets to see if BOR =3D 0,
indicating that a Brown-out has occurred. The BOR
Status bit is a =93don=92t care=94 and is not necessarily
predictable if the brown-out circuit is disabled
(BOREN<1:0> =3D 00 in the Configuration Word
register).

Bit 1 is POR (Power-on Reset). It is a =910=92 on Power-on
Reset and unaffected otherwise. The user must write a
=911=92 to this bit following a Power-on Reset. On a subsequent
Reset, if POR is =910=92, it will indicate that a
Power-on Reset has occurred (i.e., VDD may have
gone too low).

--=20
Xiaofan

--=20
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