--- Balthasar Indermuehle <bindermuehle@gmail.com>
wrote:

> > > 2. an IF statement:
> > >  
> > > Pseudo code:
> > > if (x > y) {
> > >     do something
> > > }
> > >  
> > 
> >   do the same as above but this time add an extra
> line
> > after subwf, which is sublw 0x1. Check for Zero
> again.
> > Work it out on paper and you will get it. 
> > 
> > 
> 
> Thanks John,
> 
> So an if statement essentially has to loop through?
> Is there no bit wise
> operator that lets me figure out which value of two
> is larger? 
> 

  Correct me if I am wrong but basic NOT AND and XOR
can building all sort of gates which ultimately can
build comparators. But what you want is whether the
bitwise operator can do comparison when they are equal
which lives in the instruction set. Unfortunately
subwf is a better alternative for you to determine
whether it is greater or not. Here is a macro that
uses the subwf 

;macro 		  movff
;args		  arg1 - file register,src
;			  arg2 - file register,dest
;comment	  move the contents from arg1 to arg2
;results	  now arg2 has arg1
movff	macro arg1,arg2
	movfw arg1
	movwf arg2
endm


;macro 		  cmp16ff
;args		  arg1 - addr of file register,16 bits
;			  arg2 - addr of the file register,16 bits
;			  arg3 - tmp value
;comment	  compares arg1 and arg2
;results	  arg1>arg2 -set C ,arg1==arg2 set
Z,arg2>arg1 unset C
cmp16ff	macro arg1,arg2,arg3
	movfw arg2
	subwf arg1
	movwf arg3

	btfsc STATUS,Z
	goto next_byte

	btfss STATUS,C
	goto end_cmp16ff


next_byte
	movlf arg2,FSR
	incf FSR
	movff INDF,arg3
	movlf arg1,FSR
	incf FSR
	movfw arg3
	subwf INDF
	goto end_cmp16ff

end_cmp16ff
 
endm

John


> I'm new to the bit-level way of thinking as you can
> see...
> 
> Cheers
> 
> - Balt
> 
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