-----Original Message-----
From: Jason A Alexander <jaalex@ENG.IASTATE.EDU>
To: PICLIST@MITVMA.MIT.EDU <PICLIST@MITVMA.MIT.EDU>
Date: Friday, November 21, 1997 11:53 AM
Subject: Pic16c84 input problem


>Hello all.  I am having a problem with some code I have written.
>
>I am trying to read the values of portb in an interupt sequence.
>
>Here is the code that I have written.
>
>one     bcf     intcon,7        ;Disable All interupts to prevent
disruption
>        bsf     _porta,1        ;Test bit
>        btfsc   bit1,0          ;Check to see if bit one if loaded
>        goto    second


>        movf    _portb,bit1     ;Move incoming data to W register
************************************************
this should be
         movf  _portb,w

**********************************************



>;       movwf   bit1            ;move data to bit 1
>;       bsf     bit1,0          ;Set 0 bit to 1 to show register is loaded
>        bcf     intcon,1        ;Clear Interupt flage
>        movf    bit1,w          ;Move bit into W to test
>        subwf   test            ;substract W from test
>        btfsc   _status,2       ;Skip next instruction if register is 1
>        goto    notCorrect      ;Digit was reset clear micro
>        bsf     intcon,7        ;Enable all interupts
>        retfie                  ;Return from interupt
>
>I use this with variation six time to catch six bits that come in with an
>interupt.  For some reason the correct bits are not being read from portb.
>
>When I simulate this I only seem to 0x00 loaded into the w register.
>
>I have tried moving the portb info to the w register and then two the
storage
>register and as you can see I have tried moving from portb to the storage
>register..
>
>
>Can someone tell me what I am doing wrong
>
>Thanks
>
>
>Jason
>