## ASZ280 Assembler

####

    ACKNOWLEDGMENT

         The ASZ280 cross assembler was written by John Coffman.

            John Coffman
            johninsd at gmail dot com

         The  ASZ280  assembler  is a completely table driven assem-
    bler.   This  assembler  can  process  Z280  (default),  HD64180
    (Z180),  and  Z80 code.  The following processor specific assem-
    bler directives specify  which  processor  to  target  and  with
    specific instruction options when processing the input assembler
    files.

####

    PROCESSOR SPECIFIC DIRECTIVES

    .z80 Directive

    Format:

            .z80

    The  .z80  directive  enables  processing  of  the  Z80 specific
    mnemonics.  Z180 (HD64180) and Z280 mnemonics  will  be  flagged
    with  an  <o>  error.  Addressing modes not supported by the z80
    will be flagged with an <a> error.

         The  .z80  directive  also  selects the Z80 specific cycles
    count to be output.

    .z80u Directive

    Format:

            .z80u

    The  .z80u  directive enables processing of the Z80 specific and
    Z80 undocumented instructions.  Z180 (HD64180) and Z280  mnemon-
    ics  will  be  flagged  with an <o> error.  Addressing modes not
    supported by the z80 will be flagged with an <a> error.

         The  .z80u  directive  also selects the Z80 specific cycles
    count to be output.

    .z180 Directive

    Format:

            .z180

    The  .z180  directive  enables  processing  of the Z180 specific
    mnemonics not included in the Z80 instruction  set.   Addressing
    modes  not supported by the Z180 will be flagged with an <a> er-
    ror.  A synonym of .z180 is .hd64.

         The  .z180/.hd64  directive  also  selects the Z180/HD64180
    specific cycles count to be output.

    .z280 Directive

    Format:

            .z280

    The  .z280  directive  enables  processing  of the Z280 specific
    mnemonics,  includes  i/o   instructions,   but   excludes   all
    privileged  instructions.  Addressing modes not supported by the
    Z280 will be flagged with an <a> error.

         The  .z280  directive also selects the Z280 specific cycles
    count to be output.

    .z280n Directive

    Format:

            .z280n

    The  .z280n  directive  enables  processing of the Z280 specific
    mnemonics,  excludes  i/o   instructions,   and   excludes   all
    privileged  instructions.  Addressing modes not supported by the
    Z280 will be flagged with an <a> error.

         The  .z280n directive also selects the Z280 specific cycles
    count to be output.

    .z280p Directive

    Format:

            .z280p

    The  .z280p  directive  enables  processing of the Z280 specific
    mnemonics,  includes  i/o   instructions,   and   includes   all
    privileged  instructions.  Addressing modes not supported by the
    Z280 will be flagged with an <a> error.

         The  .z280p directive also selects the Z280 specific cycles
    count to be output.

    The .__.CPU.  Variable

    The  value  of  the pre-defined symbol '.__.CPU.' corresponds to
    the selected processor type.  The following table lists the pro-
    cessor types and associated values for the ASZ280 assembler:

            Processor Type            .__.CPU. Value
            --------------            --------------
                .z80                        0x83
                .z80u                       0x87
                .z180/.hd64                 0x8B
                .z280                       0x33
                .z280n                      0x11
                .z280p                      0xF3

         The  variable '.__.CPU.' is by default defined as local and
    will not be output to the created .rel file.  The assembler com-
    mand line options -g or -a will not cause the local symbol to be
    output to the created .rel file.

         The  assembler  .globl  directive may be used to change the
    variable type to global causing its definition to be  output  to
    the  .rel file.  The inclusion of the definition of the variable
    '.__.CPU.' might be a useful means of validating that separately
    assembled  files have been compiled for the same processor type.
    The linker will report an error for variables with multiple  non
    equal definitions.

    Z280 ADDRESSING AND INSTRUCTIONS

    Registers

     Recognized Registers
     -----------------------------------------------------
      8-bit  data registers:        A,B,C,D,E,H,L,I,R
      16-Bit data registers:        BC,DE,HL,IX,IY
      Accumulator/Flag registers:   AF,AF'
      Program Counter:              PC
      Stack Pointer:                SP
     -----------------------------------------------------

    Condition Codes

     Condition Codes for Jump, Call, and Return Instructions
     -----------------------------------------------------
            NZ -    Not Zero        zero bit clear
            Z  -    Zero            zero bit set
            NC -    No Carry        carry bit clear
            C  -    Carry           carry bit set
            NV -    No Overflow     overflow bit clear
            V  -    Overflow        overflow bit set
            PE -    Parity Even     (overflow bit set)
            PO -    Parity Odd      (overflow bit clear)
            NS -    No Sign         sign bit clear
            P  -    Plus            sign bit clear
            S -     Sign            sign bit set
            M  -    Minus           sign bit set
     -----------------------------------------------------

         Condition Codes for Jump Relative Instruction
     -----------------------------------------------------
            NZ -    Not Zero        zero bit clear
            Z  -    Zero            zero bit set
            NC -    No Carry        carry bit clear
            C  -    Carry           carry bit set
     -----------------------------------------------------

    Instruction Modes

     Addressing Mode Notes
     -----------------------------------------------------
      R     8-bit registers:        A,B,C,D,E,H,L,I,R,AF,AF'

      RX    16-Bit registers:       BC,DE,HL,IX,IY,SP

      IM    Immediate               #byte, #word

      IR    Indirect Register       (HL)

      DA    Direct Address          (address)

      X     Indexed                 (HL+ofst),ofst(HL)
                                    (IX+ofst),ofst(IX)
                                    (IY+Ofst),ofst(IY)

      SX    Short Index             (HL+ofst),ofst(HL)
                                    (IX+ofst),ofst(IX)
                                    (IY+ofst),ofst(IY)
                                    -128 <= ofst <= 127

      RA    PC Relative Address     [address]
                    8-bit offset:   -128 <= ofst <= 127
                    16-bit offset:  -32768 <= ofst <= 32767

      SR    Stack Pointer Relative  (SP+ofst)

      BX    Base Index              (HL+IX),(HL+IY),(IX+IY)
     -----------------------------------------------------

      The  instruction  format  arguments  are  described in this
    table.  Note that not all addressing  arguments  are  valid  for
    every mode, refer to the z280 technical data for valid operands.

     Argument Formats
     -----------------------------------------------------
     A,B,C,D,E,H,L,AF,AF'   Explicit 8-Bit Register
     AF,AF'

     BC,DE,HL,IX,IY,SP,PC   Explicit 16-Bit Register

     DEHL                   Explicit 32-Bit Register

     r                      A,B,C,D,E,H,L Register

     rr                     BC, DE, or HL Register

     src                    Any Valid Source Argument
                            (Instruction Dependent)

     dst                    Any Valid Destination Argument
                            (Instruction Dependent)

     n                      Byte Argument

     nn                     Word Argument

     XY                     IX or IY Register

     XX                     HL, IX, or IY Register

     cc                     Condition Codes

     dat                    RST Number       0 <= dat <= 7

     p                      IM Interrupt Mode  0 <= p <= 3
     -----------------------------------------------------

    8-Bit Load Group Instructions  -
                         Addressing Modes Available
     Format         R   RX  IM  IR  DA  X   SX  RA  SR  BX
     ------        --- --- --- --- --- --- --- --- --- ---
     EX A,src       *   *       *   *   *   *   *   *   *
     EX H,L
     LD A,src       *   *   *   *   *   *   *   *   *   *
     LD dst,A       *   *   *   *   *   *   *   *   *   *
     LD dst,n       *   *       *   *   *   *   *   *   *
     -----------------------------------------------------
     LD r,src       *   *   *   *           *
     LD dst,r       *   *       *           *
     LDUD A,src                 *           *
     LDUD dst,A                 *           *
     LDUP A,src                 *           *
     LDUP dst,A                 *           *
     EXTS A
     -----------------------------------------------------

    16-Bit Load and Exchange Group Instructions  -
                         Addressing Modes Available
     Format           R   IM  IR  DA  X   SX  RA  SR  BX
     ------          --- --- --- --- --- --- --- --- ---
     EX DE,HL
     EX XY,HL
     EX (SP),XX
     EX AF,AF'
     EXX
     -----------------------------------------------------
     LD XX,src            *       *   *       *   *   *
     LD dst,XX                    *   *       *   *   *
     LD RR,src            *   *   *       *
     LD dst,RR                *   *       *
     LD dst,nn        *       *   *           *
     -----------------------------------------------------
     LD SP,src        *   *   *   *       *
     LD dst,SP                *   *       *
     LDA XX,src                   *   *       *   *   *
     POP dst          *       *   *           *
     PUSH src         *   *   *   *           *
     -----------------------------------------------------

    Block Transfer and Search Group Instructions  -
     Format                         Format
     ------                         ------
     CPD                            LDD
     CPDR                           LDDR
     CPI                            LDI
     CPIR                           LDIR
     -----------------------------------------------------

    8-Bit Arithmetic and Logic Group  -
                         Addressing Modes Available
     Format         R   RX  IM  IR  DA  X   SX  RA  SR  BX
     ------        --- --- --- --- --- --- --- --- --- ---
     ADC A,src      *   *   *   *   *   *   *   *   *   *
     ADD A,src      *   *   *   *   *   *   *   *   *   *
     AND A,src      *   *   *   *   *   *   *   *   *   *
     CP A,src       *   *   *   *   *   *   *   *   *   *
     CPL A
     DAA A
     -----------------------------------------------------
     DEC dst        *   *       *   *   *   *   *   *   *
     DIV A,src      *   *   *       *   *   *   *   *   *
     DIVU A,src     *   *   *       *   *   *   *   *   *
     EXTS A
     INC dst        *   *       *   *   *   *   *   *   *
     MULT A,src     *   *   *   *   *   *   *   *   *   *
     -----------------------------------------------------
     MULTU A,src    *   *   *   *   *   *   *   *   *   *
     NEG A
     OR A,src       *   *   *   *   *   *   *   *   *   *
     SBC A,src      *   *   *   *   *   *   *   *   *   *
     SUB A,src      *   *   *   *   *   *   *   *   *   *
     XOR A,src      *   *   *   *   *   *   *   *   *   *
     -----------------------------------------------------

    16-Bit Arithmetic Operation Instructions  -
                         Addressing Modes Available
     Format                 R   IM  IR  DA  X   RA
     ------                --- --- --- --- --- ---
     ADC XX,src             *
     ADD XX,src             *
     AND XX,A
     ADDW HL,src            *   *       *   *   *
     CPW HL,src             *   *       *   *   *
     -----------------------------------------------------
     DECW dst               *       *   *   *   *
     DIV DEHL,src           *   *       *   *   *
     DIVU DEHL,src          *   *       *   *   *
     EXTS HL
     INCW dst               *       *   *   *   *
     -----------------------------------------------------
     MULT HL,src            *   *       *   *   *
     MULTU HL,src           *   *       *   *   *
     NEG HL
     SBC XX,src             *
     SUBW HL,src            *   *       *   *   *
     -----------------------------------------------------

    Bit Manipulation, Rotate and Shift Group  -
                         Addressing Modes Available
     Format                     IR  DA  RA
     ------                    --- --- ---
     BIT dst                    *   *   *
     RES dst                    *   *   *
     RL dst                     *   *   *
     RLA
     RLC dst                    *   *   *
     RLCA
     -----------------------------------------------------
     RLD                            *
     RR dst                     *   *   *
     RR A
     RRC dst                    *   *   *
     RRCA
     RRD                            *
     -----------------------------------------------------
     SET dst                    *   *   *
     SLA dst                    *   *   *
     SRA dst                    *   *   *
     SRL dst                    *   *   *
     TSET dst                   *   *   *
     -----------------------------------------------------

    Program Control Group Instructions  -
                         Addressing Modes Available
     Format                     IR  DA  RA
     ------                    --- --- ---
     CALL cc,dst                *   *   *
     CCF
     DJNZ dst                           *
     JAF dst                            *
     JAR dst                            *
     -----------------------------------------------------
     JP cc,dst                  *   *   *
     JR cc,dst                          *
     RET cc
     RST dat
     SC nn
     SCF
     -----------------------------------------------------

    Program Control Group Instructions  -
     Format                         Format
     ------                         ------
     IN dst,(C)                     OUT (C),src
     IN A,(n)                       OUT (n),A
     INW HL,(C)                     OUTW (C),HL
     IND                            OUTD
     INDW                           OUTDW
     INDR                           OTDR
     INDRW                          OTDRW
     INI                            OUTI
     INIW                           OTIW
     INIR                           OTIR
     INIRW                          OTIRW
     TSTI (C)
     -----------------------------------------------------

    CPU Control Group Instructions  -
     Format                         Format
     ------                         ------
     DI mask                        LDCTL dst,src
     EI mask                        NOP
     HALT                           PCACHE
     IM p                           RETI
     LD A,src                       RETIL
     LD src,A                       RETN
     -----------------------------------------------------

    Extended Instructions  -
     Format                         Format
     ------                         ------
     EPUM src                       EPUF
     MEPU dst                       EPUI
     -----------------------------------------------------

    Z280 Excution Cycles

         The  instruction  cycle timing was taken from Appendix E of
    the Z280 CPU manual.  They are greatly influenced  by  the  con-
    tents of the cache.

                     Z280 Manual Appendix E Excerpt

         The  autonomous  operation  of the three stages in the
         Z280 cpu instruction pipeline makes  it  difficult  to
         calculate exact instruction execution times.  Further-
         more, execution times are affected by cache  activity;
         the current cache contents determine the number of ex-
         ternal memory transactions made during the fetch  exe-
         cution of a given instruction.

         Thus  all timings are approximate and should be looked upon
    as the smallest number of cycles.

    Z80/HD64180 ADDRESSING AND INSTRUCTIONS

         The   following   list   specifies   the  format  for  each
    Z80/HD64180 addressing mode supported by ASZ280:

            #data           immediate data
                            byte or word data
            n               byte value
            rg              a byte register
                            a,b,c,d,e,h,l
            rp              a register pair
                            bc,de,hl
            (hl)            implied addressing or
                            register indirect addressing
            (label)         direct addressing
            (ix+offset)     indexed addressing with
             offset(ix)     an offset
            label           call/jmp/jr label

    The  terms  data,  n, label, and offset, may all be expressions.
    The terms dir and offset are not allowed to be  external  refer-
    ences.   The  following  tables  list  all Z80/HD64180 mnemonics
    recognized by the ASRAB assembler.  The designation [] refers to
    a required addressing mode argument.

         Note that not all addressing modes are valid with every in-
    struction, refer to the Z80/HD64180  technical  data  for  valid
    modes.

    Inherent Instructions

            ccf             cpd
            cpdr            cpi
            cpir            cpl
            daa             di
            ei              exx
            halt            neg
            nop             reti
            retn            rla
            rlca            rld
            rra             rrca
            rrd             scf

    Implicit Operand Instructions

            adc     a,[]            adc     []
            add     a,[]            add     []
            and     a,[]            and     []
            cp      a,[]            cp      []
            dec     a,[]            dec     []
            inc     a,[]            inc     []
            or      a,[]            or      []
            rl      a,[]            rl      []
            rlc     a,[]            rlc     []
            rr      a,[]            rr      []
            rrc     a,[]            rrc     []
            sbc     a,[]            sbc     []
            sla     a,[]            sla     []
            sra     a,[]            sra     []
            srl     a,[]            srl     []
            sub     a,[]            sub     []
            xor     a,[]            xor     []

    Load Instruction

            ld      rg,[]           ld      [],rg
            ld      (bc),a          ld      a,(bc)
            ld      (de),a          ld      a,(de)
            ld      (label),a       ld      a,(label)
            ld      (label),rp      ld      rp,(label)
            ld      i,a             ld      r,a
            ld      a,i             ld      a,r
            ld      sp,hl           ld      sp,ix
            ld      sp,iy           ld      rp,#data

            ldd                     lddr
            ldi                     ldir

    Call/Return Instructions

            call    C,label         ret     C
            call    M,label         ret     M
            call    NC,label        ret     NC
            call    NZ,label        ret     NZ
            call    P,label         ret     P
            call    PE,label        ret     PE
            call    PO,label        ret     PO
            call    Z,label         ret     Z
            call    label           ret

    Jump and Jump to Subroutine Instructions

            jp      C,label         jp      M,label
            jp      NC,label        jp      NZ,label
            jp      P,label         jp      PE,label
            jp      PO,label        jp      Z,label

            jp      (hl)            jp      (ix)
            jp      (iy)            jp      label

            djnz    label

            jr      C,label         jr      NC,label
            jr      NZ,label        jr      Z,label
            jr      label

    Bit Manipulation Instructions

            bit     n,[]
            res     n,[]
            set     n,[]

    Interrupt Mode and Reset Instructions

            im      n
            im      n
            im      n
            rst     n

    Input and Output Instructions

            in      a,(n)           in      rg,(c)
            ind                     indr
            ini                     inir

            out     (n),a           out     (c),rg
            outd                    otdr
            outi                    otir

    Register Pair Instructions

            add     hl,rp           add     ix,rp
            add     iy,rp

            adc     hl,rp           sbc     hl,rp

            ex      (sp),hl         ex      (sp),ix
            ex      (sp),iy
            ex      de,hl
            ex      af,af'

            push    rp              pop     rp

    HD64180 Specific Instructions

            in0     rg,(n)
            out0    (n),rg

            otdm                    otdmr
            otim                    otimr

            mlt     bc              mlt     de
            mlt     hl              mlt     sp

            slp

            tst     a
            tstio   #data

    Z80 Undocumented Instructions

        op = adc, add, and, cp, or, sbc, sub, xor
            op      a,ixh           op      a,ixl
            op      a,iyh           or      a,iyl

        op = dec, inc
            op      ixh             inc     ixl
            op      iyh             inc     iyl

            in      ixh,(c)         in      ixl,(c)
            in      iyh,(c)         in      iyl,(c)

            ld      ixh,r           r = a, b, c, d, e
            ld      ixl,r           r = a, b, c, d, e

            ld      iyh,r           r = a, b, c, d, e
            ld      iyl,r           r = a, b, c, d, e

            ld      r,ixh           r = a, b, c, d, e
            ld      r,ixl           r = a, b, c, d, e

            ld      r,iyh           r = a, b, c, d, e
            ld      r,iyl           r = a, b, c, d, e

            ld      ixh,#n          ld      ixl,#n
            ld      iyh,#n          ld      iyl,#n

            ld      ixh,ixh         ld      ixl,ixh
            ld      ixh,ixl         ld      ixl,ixl
            ld      iyh,iyh         ld      iyl,iyh
            ld      iyh,iyl         ld      iyl,iyl

            sll     offset(ix)      sll     offset(iy)
            sll     a               sll     b
            sll     c               sll     d
            sll     e               sll     h
            sll     l

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###### Last Updated: March 2025