## AS6800 Assembler

####

    6800 REGISTER SET

       The following is a list of the 6800 registers used by AS6800:

            a,b     -       8-bit accumulators
            x       -       index register

    6800 INSTRUCTION SET

       The following tables list all 6800/6802/6808 mnemonics recog-
    nized by the AS6800 assembler.  The designation [] refers  to  a
    required addressing mode argument.  The following list specifies
    the format for each addressing mode supported by AS6800:

            #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

            ext             extended addressing

            label           branch label

    The  terms  data, dir, offset, ext, and label may all be expres-
    sions.

       Note  that  not all addressing modes are valid with every in-
    struction, refer to the 6800 technical data for valid modes.

    Inherent Instructions

            aba                     cba
            clc                     cli
            clv                     daa
            des                     dex
            ins                     inx
            nop                     rti
            rts                     sba
            sec                     sei
            sev                     swi
            tab                     tap
            tba                     tpa
            tsx                     txs
            wai

            psha                    pshb
            psh a                   psh b
            pula                    pulb
            pul a                   pul b

    Branch Instructions

            bra     label           bhi     label
            bls     label           bcc     label
            bhs     label           bcs     label
            blo     label           bne     label
            beq     label           bvc     label
            bvs     label           bpl     label
            bmi     label           bge     label
            blt     label           bgt     label
            ble     label           bsr     label

    Single Operand Instructions

            asla                    aslb
            asl a                   asl b
            asl     []

            asra                    asrb
            asr a                   asr b
            asr     []

            clra                    clrb
            clr a                   clr b
            clr     []

            coma                    comb
            com a                   com b
            com     []

            deca                    decb
            dec a                   dec b
            dec     []

            inca                    incb
            inc a                   inc b
            inc     []

            lsla                    lslb
            lsl a                   lsl b
            lsl     []

            lsra                    lsrb
            lsr a                   lsr b
            lsr     []

            nega                    negb
            neg a                   neg b
            neg     []

            rola                    rolb
            rol a                   rol b
            rol     []

            rora                    rorb
            ror a                   ror b
            ror     []

            tsta                    tstb
            tst a                   tst b
            tst     []

    Double Operand Instructions

            adca    []              adcb    []
            adc a   []              adc b   []

            adda    []              addb    []
            add a   []              add b   []

            anda    []              andb    []
            and a   []              and b   []

            bita    []              bitb    []
            bit a   []              bit b   []

            cmpa    []              cmpb    []
            cmp a   []              cmp b   []

            eora    []              eorb    []
            eor a   []              eor b   []

            ldaa    []              ldab    []
            lda a   []              lda b   []

            oraa    []              orab    []
            ora a   []              ora b   []

            sbca    []              sbcb    []
            sbc a   []              sbc b   []

            staa    []              stab    []
            sta a   []              sta b   []

            suba    []              subb    []
            sub a   []              sub b   []

    Jump and Jump to Subroutine Instructions

            jmp     []              jsr     []

    Long Register Instructions

            cpx     []
            lds     []              sts     []
            ldx     []              stx     []

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###### Last Updated: March 2025