At 19:15 20.04.97 -0700, you wrote:
>
>Would someone please provide some demo code for the PIC17C44's 'MOVxx'
>instructions? Something that would show the 'wreg' and 'p' files with
>bank switching to read/write ports.

        movlb  1                ; use register bank 1
        movlw    0x0F           ; value, to program DDRC
        movwf    ddrc           ; program DDRC
; now you can read from bits 0 - 3 and you can write to bits 4 - 7.

        movlb  0                ; use register bank 0
        movfp    porta,wreg     ; read value from PORTA into WREG
        swapf  wreg             ; change nibbles
      movlb  1          ; register bank 1
      movpf  wreg,portc ; write value into PORTC (similar to "movwf  portc")

>
>Also a question about portA on this chip. Since there's no direction
>control, what method is used, to use it, ...

PORT-A has a fixed configuration. Bits 0 and 1 are only inputs.
Bits 2 and 3 are inputs and open collector aoutputs. So if you want to read
>from Bits 2 or 3, then you have to output a "1" into these bits.
Aftwerwards, you can read the actual status of the pins.
Bits 4 and 5 have special functions for serial I/O, and should not
be used differently.

regards,

Wolfra,


+-----------------------------------------------------+
| Wolfram Liebchen                                    |
| Forschungsinstitut fŸr Optik, TŸbingen, Deutschland |
| mailto:liebchen@ffo.fgan.de                         |
+-----------------------------------------------------+