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AS6805 Assembler

6805 REGISTER SET 

The following is a list of the 6805 registers used by AS6805:  

        a       -       8-bit accumulator
        x       -       index register


6805 INSTRUCTION SET 


   The  following  tables  list all 6805 mnemonics recognized by
the AS6805 assembler.  The designation [] refers to  a  required
addressing  mode  argument.   The  following  list specifies the
format for each addressing mode supported by AS6805:  

        #data           immediate data
                        byte or word data

        *dir            direct page addressing
                        (see .setdp directive)
                        0 <= dir <= 255 

        ,x              register indirect addressing
                        zero offset

        offset,x        register indirect addressing
                          0 <= offset <= 255   --- byte mode
                        256 <= offset <= 65535 --- word mode
                        (an externally defined offset uses the
                         word mode)

        ext             extended addressing

        label           branch label


The terms data, dir, offset, and ext may all be expressions.  

   Note  that  not all addressing modes are valid with every in-
struction, refer to the 6805 technical data for valid modes.  


Control Instructions 

        clc             cli
        nop             rsp
        rti             rts
        sec             sei
        stop            swi
        tax             txa
        wait


Bit Manipulation Instructions 

        brset   #data,*dir,label
        brclr   #data,*dir,label

        bset    #data,*dir
        bclr    #data,*dir


Branch Instructions 

        bra     label           brn     label
        bhi     label           bls     label
        bcc     label           bcs     label
        bne     label           beq     label
        bhcc    label           bhcs    label
        bpl     label           bmi     label
        bmc     label           bms     label
        bil     label           bih     label
        bsr     label


Read-Modify-Write Instructions 

        nega            negx
        neg     []

        coma            comx
        com     []

        lsra            lsrx
        lsr     []

        rora            rorx
        ror     []

        asra            asrx
        asr     []

        lsla            lslx
        lsl     []

        rola            rolx
        rol     []

        deca            decx
        dec     []

        inca            incx
        inc     []

        tsta            tstx
        tst     []

        clra            clrx
        clr     []


Register\Memory Instructions 

        sub     []              cmp     []
        sbc     []              cpx     []
        and     []              bit     []
        lda     []              sta     []
        eor     []              adc     []
        ora     []              add     []
        ldx     []              stx     []


Jump and Jump to Subroutine Instructions 

        jmp     []              jsr     []

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