Thanks kindly for all of the replies!

> On Sun, 16 Feb 2003 15:31:45 -0800, Neil Bradley wrote:
> movlw   PORTA_IN        ; Get port A's input setting
> movwf   TRISA           ; Set up appropriate tristating
>
> Using MOVLW you are getting the address of the variable not its
> contents.
>
> Try
> movlw 0x40 or B'01000000'
> movwf TRISA
>
> The PORTA_IN did you #def or EQU it in your listing?

Sorry to not have been more clear. I have put in the beginning:

                INCLUDE         "P18f252.inc"

And later:

; Generic definitions go here

BIT_0           equ             b'00000001'             ; Bit 0
BIT_1           equ             b'00000010'             ; Bit 1
BIT_2           equ             b'00000100'             ; Bit 2
BIT_3           equ             b'00001000'             ; Bit 3
BIT_4           equ             b'00010000'             ; Bit 4
BIT_5           equ             b'00100000'             ; Bit 5
BIT_6           equ             b'01000000'             ; Bit 6
BIT_7           equ             b'10000000'             ; Bit 7

; Specific definitions go here

; Port A definitions

PORTA_OUT       equ             (BIT_0 | BIT_1 | BIT_2 | BIT_3 | BIT_4 | BIT_5)
PORTA_IN        equ             ((~PORTA_OUT) & 0x7f)   ; Leave bit 7 alone!

; Port B definitions

PORTB_OUT       equ             (BIT_1 | BIT_2 | BIT_3 | BIT_4 | BIT_5 | BIT_6 | BIT_7)
PORTB_IN        equ             (~PORTB_OUT)

; Port C definitions

BIT_INH         equ             b'00000001'             ; Inhibit bit definition
BIT_CHA         equ             b'00000010'             ; Channel A definition
BIT_CHB         equ             b'00000100'             ; Channel B definition
BIT_SCLK        equ             b'00001000'             ; Serial clock (SPI)
BIT_SDATA       equ             b'00100000'             ; Serial data (SPI)
BIT_DACK        equ             b'01000000'             ; Data acknowledgement to T89C51RD2

PORTC_OUT       equ             (BIT_INH | BIT_CHA | BIT_CHB | BIT_DACK)
PORTC_IN        equ             (~PORTC_OUT)

I've noticed that the values being loaded up in the W register are indeed
as I expect. It's just reading the values of TRISA/B/C through the MPLAB
IDE after they've been set that aren't right! I can forgive bit 7 in port
A since it's nonexistent/undefined, but the oddities in the remainder of
port A and B are a mystery.

Thanks kindly to the Dave, David, and Colin!

-->Neil

-------------------------------------------------------------------------------
Neil Bradley            In the land of the blind, the one eyed man is not
Synthcom Systems, Inc.  king - he's a prisoner.
ICQ #29402898

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