Hi Jay,

You can't set bit position using register (or even W). It must be a
literal. bcf PORTB, 0 is ok, but bcf PORTB, test is not since test is a
register. If it did anything, it would operate on address of test and
not test content. I'm guessing the address of test is greater than 7, so
the compiler is giving you a warning.

Also, don't use bit operations on PORT. Instead of bcf, you might do
movf    PORTB, W
movwf   tempB
bcf     tempB, 0        ;must use literal as bit position
movf    tempB, W
movwf   PORTB

Jay Couture wrote:
>
> Hello,   I am trying to use a file register as a mask to clear a bit on
> PORTB. I do get a warning when I compile:
>
>  Warning[202] E:\PIC\CODE\test.ASM 113 : Argument out of range.  Least
> significant bits used.
>
> Here is the code:
> Let's say test = 1 for argument's sake (I've tested this and it does)
>   movwf   test           ;save request
>   movlw   .1             ;need to subtract 1 so range is from 0 to 7
>   subwf   test, W        ;w = test - 1
>   movwf   test           ;test = test - 1    test = 0
>   bcf   PORTB, test      ;clear PORTB.0
>
> It doesn't matter what bit I want to clear, bit five is the only one that
> is ever cleared regardless of the value of test. I should point out that
> test is in files register 0x015, so it makes sense why bit 5 (the lower
> nybble) is the only one cleared, but why is it using it's address and not
> it's value?
>
> Thanks, Jay