## AS430 Assembler

####

    MPS430 REGISTER SET

    The following is a list of the MPS430 registers used by AS430:

    Sixteen 16-bit registers provide adddress, data, and
    special functions:
            pc  /   r0      -       program counter
            sp  /   r1      -       stack pointer
            sr  /   r2      -       status register
            cg1 /   r2      -       constant generator 1
            cg2 /   r3      -       constant generator 2
                    r4      -       working register r4
                    r5      -       working register r5
                    ...
                    r14     -       working register r14
                    r15     -       working register r15

####

    MPS430 ADDRESSING MODES

    The following list specifies the format for each addressing mode
    supported by AS430:

            Source/Destination Operand Addressing Modes
            As/Ad   Addressing Mode Syntax  Description
            -----   --------------- ------  -----------
            00/0    Register mode   Rn      Register contents are operand.
            01/1    Indexed mode    X(Rn)   (Rn + X) points to the operand,
                                            X is stored in the next word.
            01/1    Symbolic mode   ADDR    (PC + X) points to the operand,
                                            X is stored in the next word,
                                            Indexed mode X(PC) is used.
            01/1    Absolute mode   &ADDR   The word following the
                                            instruction, contains the
                                            absolute address.
            10/-    Indirect        @Rn     Rn is used as a pointer to the
                    register mode           operand.
            11/-    Indirect        @Rn+    Rn is used as a pointer to the
                    autoincrement           operand. Rn is incremented
                                            afterwards.
            11/-    Immediate mode  #N      The word following the
                                            instruction contains the
                                            immediate constant N. Indirect
                                            autoincrement mode @PC+ is used.

    The  terms  ADDR, X and N may all be expressions.  Note that not
    all addressing modes are valid with every instruction, refer  to
    the MPS430 technical data for valid modes.

####

    MPS430 Instruction Mnemonics

    The following table lists all MPS430 family mnemonics recognized
    by the AS430 assembler.  The designations src and dst  refer  to
    required source and/or destination addressing mode arguments.

            * ADC[.W];ADC.B  dst        dst + C -> dst
              ADD[.W];ADD.B  src,dst    src + dst -> dst
              ADDC[.W];ADDC.B           src,dst src + dst + C -> dst
              AND[.W];AND.B  src,dst    src .and. dst -> dst
              BIC[.W];BIC.B src,dst     .not.src .and. dst -> dst
              BIS[.W];BIS.B src,dst     src .or. dst -> dst
              BIT[.W];BIT.B src,dst     src .and. dst
            * BR dst                Branch to .......
            * BRANCH dst            Branch to .......
              CALL dst              PC+2 -> stack, dst -> PC
            * CLR[.W];CLR.B dst     Clear destination
            * CLRC                  Clear carry bit
            * CLRN                  Clear negative bit
            * CLRZ                  Clear zero bit
              CMP[.W];CMP.B src,dst     dst - src
            * DADC[.W];DADC.B dst       dst + C -> dst (decimal)
              DADD[.W];DADD.B src,dst   src + dst + C -> dst (decimal)
            * DEC[.W];DEC.B dst     dst - 1 -> dst
            * DECD[.W];DECD.B dst   dst - 2 -> dst
            * DINT                  Disable interrupt
            * EINT                  Enable interrupt
            * INC[.W];INC.B dst     dst + 1 -> dst
            * INCD[.W];INCD.B dst   dst + 2 -> dst
            * INV[.W];INV.B dst     Invert destination
              JC/JHS Label          Jump to Label if Carry-bit is set
              JEQ/JZ Label          Jump to Label if Zero-bit is set
              JGE Label             Jump to Label if (N .XOR. V) = 0
              JL Label              Jump to Label if (N .XOR. V) = 1
              JMP Label             Jump to Label unconditionally
              JN Label              Jump to Label if Negative-bit is set
              JNC/JLO Label         Jump to Label if Carry-bit is reset
              JNE/JNZ Label         Jump to Label if Zero-bit is reset
              MOV[.W];MOV.B src,dst     src -> dst
            * NOP                   No operation
            * POP[.W];POP.B dst     Item from stack, SP+2 -> SP
              PUSH[.W];PUSH.B src   SP - 2 -> SP, src -> @SP
              RETI                  Return from interrupt
                                        TOS -> SR, SP + 2 -> SP
                                        TOS -> PC, SP + 2 -> SZP
            * RET                   Return from subroutine
                                        TOS -> PC, SP + 2 -> SP
            * RLA[.W];RLA.B dst     Rotate left arithmetically
            * RLC[.W];RLC.B dst     Rotate left through carry
              RRA[.W];RRA.B dst     MSB -> MSB . ....LSB -> C
              RRC[.W];RRC.B dst     C -> MSB . ......LSB -> C
            * SBC[.W];SBC.B dst     Subtract carry from destination
            * SETC                  Set carry bit
            * SETN                  Set negative bit
            * SETZ                  Set zero bit
              SUB[.W];SUB.B src,dst     dst + .not.src + 1 -> dst
              SUBC[.W];SUBC.B src,dst   dst + .not.src + C -> dst
              SBB[.W];SBB.B src,dst     dst + .not.src + C -> dst
              SWPB dst              swap bytes
              SXT dst               Bit7 -> Bit8 ........ Bit15
            * TST[.W];TST.B dst     Test destination
              XOR[.W];XOR.B src,dst     src .xor. dst -> dst
                    Note: Asterisked Instructions
                    Asterisked (*) instructions are emulated.
                    They are replaced with coreinstructions
                    by the assembler.

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###### Last Updated: March 2025