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ASEZ80 Assembler

PROCESSOR SPECIFIC DIRECTIVES 


   The  ASEZ80 assembler is a port of the ASZ80 assembler.  This
assembler can process EZ80 code in Z80 and ADL modes in any com-
bination  within  the  source  file.   The  following  processor
specific assembler directives specify which mode  the  assembler
is  to  process  the assembler source code.  The default mode of
the assembler is Z80.  

  


.z80 Directive 

Format:  

        .z80    [n] 

The  assembler is informed by the .z80 directive to assemble the
subsequent code using the banked 16-Bit addressing  capabilities
of the EZ80 processor.  The optional argument, n, allows the as-
sembly mode to be controlled by a varaible.   A  non-zero  value
for  n  enables  Z80 mode and a zero value enables the ADL mode.
The default mode of the assembler is Z80.  


.adl Directive 

Format:  

        .adl    [n] 

The  assembler is informed by the .adl directive to assemble the
subsequent code using the full 24-Bit addressing capabilities of
the EZ80 processor.  The optional argument, n, allows the assem-
bly mode to be controlled by a varaible.  A non-zero value for n
enables  ADL  mode  and  a zero value enables the Z80 mode.  The
default mode of the assembler is Z80.  


.msb Directive 

Format:  

        .msb    n 


   The  assembler operator '>' selects the upper byte (MSB) when
included in an assembler instruction.  The normal assembler mode
is  to select bits <15:8> as the MSB.  The .msb directive allows
the programmer to specify a particular byte as  the  'MSB'  when
the address space is larger than 16-bits.  

   For a 24-bit EZ80 address the assembler directive .msb n con-
figures the assembler to select a particular byte as MSB.  Given
a  24-bit  address  of  Mmn (M is <23:16>, m is <15:8>, and n is
<7:0>) the following examples show how to  select  a  particular
address byte:  

        .msb 1          ;select byte 1 of address
                        ;
        LD A,>Mmn       ;byte m <15:8> ==>> A
        ...

        .msb 2          ;select byte 2 of address
                        ;
        LD A,>Mmn       ;byte M <23:16> ==>> A
        LD MB,A         ;place in MBASE register



EZ80 ADDRESSING AND INSTRUCTIONS 

Instruction Symbols 


        b          Bit select
                        (000 = bit 0, 001 = bit 1,
                         010 = bit 2, 011 = bit 3,
                         100 = bit 4, 101 = bit 5,
                         110 = bit 6, 111 = bit 7)
        cc         condition code C, NC, Z, NZ, P, M, PE, PO
                   test of single bit in FLAGS register
        cc'        condition code C, NC, Z, NZ
                   test of single bit in FLAGS register
        d          an 8-bit two's complement displacement with
                   value from -128 to 127.
        I          Interrupt Page Address Register
        ir or ir'  8-bit CPU register IXH(IX:[15:8]),
                   IXL (IX:[7:0], IYH (IY:[15:8]), IYL (IY:[7:0])
        IX/Y       CPU register IX or IY
        (IX/Y+d)   A location in memory with address formed by the
                   sum of the contents of the Index Register, IX
                   or IY, and the two's complement displacement d.
        MB         Z80 Memory Mode Base Address Register
        Mmn        A 24-bit immediate data value
        (Mmn)      A 24-bit value indicating a location in
                   memory at this address.
        mn         A 16-bit immediate data value
        (mn)       A 16-bit value indicating a location in
                   memory at this address.
        n          8-bit immediate data value
        R          Refresh Counter Register
        r or r'    8-bit CPU register A, B, C, D, E, H, L
        rr         16 or 24-bit CPU register BC, DE, HL
        rxy        16 or 24-bit CPU register BC, DE, HL, IX, IY
        SP         Stack Pointer, Can indicate either the
                   StackPointer Short register (SPS) or the
                   StackPointer Long register (SPL).

        C  -    carry bit set
        NC -    carry bit clear
        Z  -    zero bit set
        NZ -    zero bit clear
        M  -    sign bit set
        P  -    sign bit clear
        PE -    parity even
        PO -    parity odd


        The terms b, d, Mmn, mn, and n may all be expressions.  


EZ80 Instructions 

   The  following list of instructions (with explicit addressing
modes) are available for the EZ80.  

-----------------------------------------------------------------------

        ADC A,(HL)              DEC (HL)                INI
        ADC A,ir                DEC ir                  INI2
        ADC A,(IX/Y+d)          DEC IX/Y                INI2R
        ADC A,n                 DEC (IX/Y+d)
        ADC A,r                 DEC r                   INIM
        ADC HL,rr               DEC rr                  INIMR
        ADC HL,SP               DEC SP
                                                        INIR
        ADD A,(HL)              DI                      INIRX
        ADD A,ir
        ADD A,(IX/Y+d)          DJNZ d                  JP cc,Mmn
        ADD A,n                                         JP HL
        ADD A,r                 EI                      JP IX/Y
        ADD HL,rr                                       JP Mmn
        ADD HL,SP               EX AF,AF'
        ADD IX/Y,rxy            EX DE,HL                JR cc',d
        ADD IX/Y,SP             EX (SP),HL              JR d
                                EX (SP),IX/Y
        AND A,HL                                        LD A,I
        AND A,ir                EXX                     LD A,(IX/Y+d)
        AND A,(IX/Y+d)                                  LD A,MB
        AND A,n                 HALT                    LD A,(Mmn)
        AND A,r                                         LD A,R
                                IM n                    LD A,(rr)
        BIT b,(HL)              IM A,(n)                LD (HL),IX/Y
        BIT b, (IX/Y+d)         IN r,(BC)               LD (HL),n
        BIT b,r                                         LD (HL),r
                                IN0 r,(n)               LD (HL),rr
        CALL cc,Mmn                                     LD IY,(SP+n)
        CALL mn                 INC (HL)                LD I,HL
                                INC ir                  LD I,A
        CP A,(HL)               INC IX/Y                LD ir,ir'
        CP A,ir                 INC (IX/Y+d)            LD ir,n
        CP A,(IX/Y+d)           INC r                   LD ir,r
        CP A,r                  INC SP                  LD IX/Y,(HL)
                                                        LD IX/Y,(IX/Y+d)
        CPD                     IND                     LD IX/Y,Mmn
        CPDR                    IND2                    LD IX/Y,(Mmn)
                                IND2R                   LD (IX/Y+d),IX/Y
        CPI                                             LD (IX/Y+d),n
        CPIR                    INDM                    LD (IX/Y+d),r
                                INDMR                   LD (IX/Y+d),rr
        CPL                                             LD MB,A
                                INDR                    LD (Mmn),A
        DAA                     INDRX                   LD (Mmn),IX/Y

-----------------------------------------------------------------------

        LD (Mmn),rr             OTDR                    RL r
        LD (Mmn),SP             OTDRX
        LD R,A                                          RLA
        LD r,(HL)               OTI2R
        LD r,ir                                         RLC (HL)
        LD r,(IX/Y+d)           OTIM                    RLC (IX/Y+d)
        LD r,n                  OTIMR                   RLC r
        LD r,r'
        LD rr,(HL)              OTIR                    RLCA
        LD rr,(IX/Y+d)          OTIRX
        LD rr,Mmn                                       RLD
        LD rr,(Mmn)             OUT (BC),r
        LD (rr),A               OUT (C),r               RR (HL)
        LD SP,HL                OUT (n),A               RR (IX/Y+d)
        LD SP,IX/Y                                      RR r
        LD SP,Mmn               OUTD
        LD SP,(Mmn)             OUTD2                   RRA
        
        LDD                     OUTI                    RRC (HL)
        LDDR                    OUTI2                   RRC (IX/Y+d)
                                RL (IX+d)               RRC r
        LDI                     RL (IY+d
        LDIR                                            RRCA
                                PEA IX+d
        LEA IX/Y,IX+d           PEA IY+d                RRD
        LEA IX/Y,IY+d
        LEA rr,IX+d             POP AF                  RSMIX
        LEA rr,IY+d             POP IX/Y
                                POP rr                  RST n
        MLT rr
        MLT SP                  PUSH AF                 SBC A,(HL)
                                PUSH IX/Y               SBC A,ir
        NEG                     PUSH rr                 SBC A,(IX/Y+d)
                                                        SBC A,n
        NOP                     RES b,(IX/Y+d)          SBC A,r
                                RES b,r                 SBC HL,rr
        OR A,(HL)                                       SBC HL,SP
        OR A,ir                 RET
        OR A,(IX/Y+d)           RET cc                  SCF
        OR A,n
        OR A,r                  RETI                    SET b,(HL)
                                                        SET b,(IX/Y+d)
        OTD2R                   RETN                    SET b,r
        
        OTDM                    RL (HL)                 SLA (HL)
        OTDMR                   RL (IX/Y+d)             SLA (IX/Y+d)

-----------------------------------------------------------------------

        SLA r                   STMIX                   TSTIO n
        
        SLP                     SUB A,(HL)              XOR A,(HL)
                                SUB A,ir                XOR A,ir
        SRA (HL)                SUB A,(IX/Y+d)          XOR A,(IX/Y+d)
        SRA (IX/Y+d)            SUB A,n                 XOR A,n
        SRA r                   SUB A,r                 XOR A,r
        
        SRL (HL)                TST A,(HL)
        SRL (IX/Y+d)            TST A,n
        SRL r                   TST A,r


   The  accumulator  'A' argument is optional in all of the fol-
lowing instructions:  

        ADC A,...               CP A,...                SUB A,...
        ADD A,...               OR A,...                TST A,...
        AND A,...               SBC A,...               XOR A,...


   The  following  tables,  organized by instruction type, lists
all possible EZ80/Z80  mnemonic  extensions  recognized  by  the
ASEZ80  assembler.   The designation [] refers to a required ad-
dressing mode argument shown in the table  above.   The  allowed
mnemonic  suffixes  are  denoted within the enclosing delimiters
().  Mnemonics specified with illegal  or  unrecognized  suffixs
will be flagged with q or a errors.  


Arithmetic Instructions 

        adc (.l, .s)    [],[]
        add (.l, .s)    [],[]
        cp  (.l, .s)    [],[]
        daa
        dec (.l, .s)    []
        inc (.l, .s)    []
        mlt (.l, .s)    []
        neg
        sbc (.l, .s)    [],[]
        sub (.l, .s)    [],[]

 
Bit Manipulation Instructions 

        bit (.l, .s)    [],[]
        res (.l, .s)    [],[]
        set (.l, .s)    [],[]


Block Transfer and Compare Instructions 

        cpd (.l, .s)            cpdr (.l, .s)
        cpi (.l, .s)            cpir (.l, .s)
        ldd (.l, .s)            lddr (.l, .s)
        ldi (.l, .s)            ldir (.l, .s)


Exchange Instructions 

        ex (.l, .s)     [],[]
        exx


Input/Output Instructions 

        in      [],[]           in0     [],[]
        ind   (.l, .s)          indr  (.l, .s)
        indx  (.l, .s)
        ind2  (.l, .s)          ind2r (.l, .s)
        indm  (.l, .s)          indmr (.l, .s)
        ini   (.l, .s)          inir  (.l, .s)
        inim  (.l, .s)          inimr (.l, .s)
        otdm  (.l, .s)          otdmr (.l, .s)
        otdrx (.l, .s)
        otim  (.l, .s)          otimr (.l, .s)
        otirx (.l, .s)
        out   (.l, .s)  [],[]
        out0  (.l, .s)  [],[]
        outd  (.l, .s)          otdr  (.l, .s)
        outd2 (.l, .s)          otdr2 (.l, .s)
        outi  (.l, .s)          otir  (.l, .s)
        outi2 (.l, .s)          oti2r (.l, .s)
        tstio   []


Load Instructions 

        ld   (.l, .s, .il, .is, .lil, .sis)     [],[]
        lea  (.l, .s)   []      pea  (.l, .s)   []
        pop  (.l, .s)   []      push (.l, .s)   []


Logical Instructions 

        and (.l, .s)    [],[]
        cpl (.l, .s)
        or  (.l, .s)    [],[]
        tst (.l, .s)    [],[]
        xor (.l, .s)    [],[]


Processor Control Instructions 

        ccf             di              ei
        halt            im              nop
        rsmix           stmix
        scf             slp


Program Flow Instructions 

        call (.il, .is)         []
        call (.il, .is)         CC,[]
        djnz    []
        jp   (.l, .s, .lil, .sis)       []
        jp   (.l, .s, .lil, .sis)       CC,[]
        jr      []
        jr      CC,[]
        ret  (.l)
        ret  (.l)       CC
        reti (.l)
        retn (.l)
        rst  (.l, .s)   []


Shift and Rotate Instructions 

        rl  (.l, .s)    []      rla
        rlc (.l, .s)    []      rlca
        rld                     rrd
        rr  (.l, .s)    []      rra
        rrc (.1, .s)    []      rrca
        sla (.l, .s)    []
        sra (.l, .s)    []
        srl (.l, .s)    []

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Last Updated: April 2009