Najemy, Daniel <PICLIST@MITVMA.MIT.EDU> wrote:

> Does anyone out there have a handy routine available to initialize
> ram in a 16c63 on power up?

Sure, Daniel... This one isn't the fastest possible, but it works:

        CLRF    PCLATH      ;POINT AT PROGRAM SEGMENT 0.

        MOVLW   FRSTGP0     ;PREPARE TO ZERO ALL GENERAL-
        MOVWF   FSR         ;PURPOSE REGISTERS.

    CLRRAM:

        MOVLW   LASTGP0+1   ;ARE WE POINTING PAST THE
        XORWF   FSR,W       ;FINAL PAGE-0 REGISTER?

        SKPNZ               ;IF NOT, SKIP AHEAD.

        BSF     FSR,5       ;OTHERWISE, ADJUST FSR TO SKIP
                            ;OVER THE PAGE-1 SPECIAL-PURPOSE
                            ;REGISTERS.

        CLRF    USEFSR      ;ZERO THE REGISTER AT WHICH WE'RE
                            ;POINTING.

        INCFSZ  FSR         ;HAVE WE DONE THEM ALL?
        GOTO    CLRRAM      ;IF NOT, LOOP BACK AND ZERO ANOTHER.

You have to define FRSTGP0 and LASTGP0 to the addresses of the first
and last Page-0 general-purpose registers, of course... And "USEFSR"
is my name for the register that Microchip calls "INDF".

-Andy

=== Andrew Warren - fastfwd@ix.netcom.com
=== Fast Forward Engineering - Vista, California
=== http://www.geocities.com/SiliconValley/2499