>         subwf   RxHold

cant the result of this instruction goto w and thus solve the problem of
destroying the contents of RxHold
Justin
-----Original Message-----
From: Tony Nixon [mailto:Tony.Nixon@ENG.MONASH.EDU.AU]
Sent: Wednesday, 19 December 2001 07:44
To: PICLIST@MITVMA.MIT.EDU
Subject: Re: [PIC]: Need help with 16F877 USART RS232


Tim Webb wrote:

Change this block....

> MnLoop
>         call    Receive
>
>         movlw   'A'
>         subwf   RxHold
>         btfss   STATUS, Z
>         goto    no_a
>
>         movlw   01h             ; Set RB0 Hi if 'A' Received
>         movwf   PORTB
>
>         movwf   TXREG
>         call    TransWt
>         goto    MnLoop
>
> no_a
>         movlw   'B'
>         subwf   RxHold
>         btfss   STATUS, Z
>         goto    no_b
>
>         movlw   02h             ; Set RB1 Hi if 'B' Received
>         movwf   PORTB
>
>         goto    MnLoop
>
> no_b
>           goto  MnLoop


To this....

MnLoop
        call    Receive

        movlw   'A'
        xorwf   RxHold,W
        btfss   STATUS, Z
        goto    no_a

        movlw   01h             ; Set RB0 Hi if 'A' Received
        movwf   PORTB

        movwf   TXREG
        call    TransWt
        goto    MnLoop


no_a
        movlw   'B'
        xorwf   RxHold,W
        btfss   STATUS, Z
        goto    no_b

        movlw   02h             ; Set RB1 Hi if 'B' Received
        movwf   PORTB

        goto    MnLoop

no_b
        clrf PORTB              ; RB0 RB1 = Low
        goto  MnLoop


--
Best regards

Tony

mICros
http://www.bubblesoftonline.com
mailto:sales@bubblesoftonline.com

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