On 3/7/07, michael brown <n5qmg@earthlink.net> wrote:

> Read about them, you need to know this stuff.  They're just like option
> switches, you turn them on or off.  You'll see that the CLKOUT stuff
> passes the Fosc/4 clock out a port pin making it unusable to you.  The
> ER thingy is also tying up one of your port pins thinking that you have
> an external R/C connected to act as the clock.  You could try this for
> your CONFIG word settings:

Thanks for your input. I've now read through about the configuration
bits and port setups even more. Yet I seem to miss something, because
PORTA won't change values when I try to.

    __CONFIG _CP_OFF & _WDT_OFF & _BODEN_OFF & _PWRTE_ON &
_INTOSC_OSC_NOCLKOUT & _MCLRE_OFF & _LVP_OFF

start
        clrf    PORTA
        clrf    PORTB

        ; reset and initialize ports
        bsf     STATUS, RP0                     ; select bank1 for
configuration of TRISA/TRISB
        bcf     STATUS, RP1

        movlw   b'00000111'
        movwf   CMCON                           ; turn off the
comparator function for PORTA

        movlw   b'11111000'                     ; RA[3:7] inputs
        movwf   TRISA                           ; RA[0:2] outputs

        movlw   b'00000000'                     ; RB[0:5] outputs
        movwf   TRISB                           ; RB[6:7] unusable
(timer crystal)
        bcf     STATUS, RP0

        ; none of these below works, PORTA is still 0
        movlw   1
        movwf   PORTA
        movlw   2
        movwf   PORTA
        movlw   3
        movwf   PORTA
        movlw   4
        movwf   PORTA
        movlw   5
        movwf   PORTA
        movlw   6
        movwf   PORTA
        movlw   7
        movwf   PORTA
        movlw   8
        movwf   PORTA
        movlw   9
        movwf   PORTA

Have I missed something obvious? Because I really can't understand
what's going on.


-- 
- Rikard.
-- 
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