Unlike the 16 series, in the 18 series INCF and DECF affect the carry flag.

DECF is treated like a subtraction of one.

Since for subtraction the carry is treated as "not borrow", the carry will
be set for every value except 0x00, which will cause a borrow.

Bob Ammerman
RAm Systems


----- Original Message -----
From: "Alan B. Pearce" <A.B.Pearce@RL.AC.UK>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Monday, July 21, 2003 8:22 AM
Subject: Re: [PIC] : 18F452 MPLAB SIM Question


> >When any GPR is decremented using the DECF instruction, the register
> >is getting decremented, but the C bit (STATUS,0) is getting set no
> >matter what the value of the register.
> >
> >Why is this so ? Is this a bug ? Anyone alse face the same problem ?
>
> What does the instruction set portion of the datasheet say should happen
for
> this instruction?
>
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