Scott Dattalo wrote:
>>          dbankif gbankadr
>>          movf    lastb, w    ;make temp copy of previous input bits
>>          movwf   ireg2
>>          dbankif portb
>>          movf    portb, w    ;end the mismatch condition
>>          bcf     intcon, rbif ;clear the interrupt condition
>>          movf    portb, w    ;get base value for next change detect
>>          dbankif gbankar
>>          movwf   lastb       ;update last IR input bits state
>>          xorwf   ireg2       ;make flags for changed bits in IREG2
>
>
> Wouldn't it be faster to do this?
>
>  ;dbank stuff
>       movf   PORTB,W
>       bcf    INTCON,RBIF
>       movf   PORTB,W           ;get base value for next change detect
>  ;dbank stuff
>       xorwf  lastb,W           ;get differences from last time
>       xorwf  lastb,F           ;save this one as the new last
>       movwf  ireg2             ;save the differences

Yup, looks a little faster.  The code I posted above was ripped from a
18F252 project, the project specific stuff removed, then modified to make it
more generic for the 16 family.  I didn't try to optimize the result.


*****************************************************************
Embed Inc, embedded system specialists in Littleton Massachusetts
(978) 742-9014, http://www.embedinc.com

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics