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asem.pas
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asem.pas
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{ Casio HD61700 assembler }
unit Asem;
interface
uses
SysUtils;
var
{ assembler input }
loc: word;
wmd: integer; { 0 if 8-bit memory access, 1 if 16-bit memory access }
InBuf: string[64];
{ assembler output }
InIndex: integer;
OutBuf: array[0..3] of byte;
OutIndex: integer;
procedure Assemble;
implementation
type
t_kind = (
INHERENT,
RTN_ARG,
JR_ARG,
CAL_ARG,
JP_ARG,
REGISTER,
REGJR,
REGIM8,
IM8,
REGJRIM8,
REGM,
AN_ARG,
AD_ARG,
ANW_ARG,
ADW_ARG,
ANM_ARG,
ADBM_ARG,
GRE_ARG,
PRE_ARG,
GSR_ARG,
PSR_ARG,
PSRM_ARG,
GST_ARG,
PST_ARG,
MOVEB,
MOVEW,
MOVEM,
LDM_ARG,
LD_ARG,
LDW_ARG,
ST_ARG,
STW_ARG,
DB_ARG
);
tab = record
str: string[5];
val2: word;
case boolean of
True: (kind: t_kind);
False: (val1: word);
end;
const
PLUS = $0000;
MINUS = $0080;
ANYTHING = 0; { unused value }
NMNEM = 137; { index of the last item in the 'mnem' array }
{ first opcode in the upper byte of the word 'val2',
second opcode in bits 6,5 of the lower byte of the word 'val2' }
mnem: array [0..NMNEM] of tab = (
{ no operands }
( str:'bup'; val2:$D800; kind:INHERENT ),
( str:'bdn'; val2:$D900; kind:INHERENT ),
( str:'nop'; val2:$F800; kind:INHERENT ),
( str:'clt'; val2:$F900; kind:INHERENT ),
( str:'fst'; val2:$FA00; kind:INHERENT ),
( str:'slw'; val2:$FB00; kind:INHERENT ),
( str:'cani'; val2:$FC00; kind:INHERENT ),
( str:'rtni'; val2:$FD00; kind:INHERENT ),
( str:'off'; val2:$FE00; kind:INHERENT ),
( str:'trp'; val2:$FF00; kind:INHERENT ),
{ conditional code }
( str:'rtn'; val2:$F000; kind:RTN_ARG ),
{ conditional relative }
( str:'jr'; val2:$B000; kind:JR_ARG ),
{ conditional absolute }
( str:'cal'; val2:$7000; kind:CAL_ARG ),
{ conditional absolute |
unconditional with a directly specified register |
unconditional indirect with a directly specified register }
( str:'jp'; val2:$3000; kind:JP_ARG ),
{ single directly specified register }
( str:'phs'; val2:$2600; kind:REGISTER ),
( str:'phu'; val2:$2700; kind:REGISTER ),
( str:'pps'; val2:$2E00; kind:REGISTER ),
( str:'ppu'; val2:$2F00; kind:REGISTER ),
( str:'phsw'; val2:$A600; kind:REGISTER ),
( str:'phuw'; val2:$A700; kind:REGISTER ),
( str:'ppsw'; val2:$AE00; kind:REGISTER ),
( str:'ppuw'; val2:$AF00; kind:REGISTER ),
{ single directly specified register with an optional relative jump }
( str:'ldl'; val2:$1300; kind:REGJR ),
( str:'rod'; val2:$1800; kind:REGJR ),
( str:'rou'; val2:$1820; kind:REGJR ),
( str:'bid'; val2:$1840; kind:REGJR ),
( str:'biu'; val2:$1860; kind:REGJR ),
( str:'did'; val2:$1A00; kind:REGJR ),
( str:'diu'; val2:$1A20; kind:REGJR ),
( str:'byd'; val2:$1A40; kind:REGJR ),
( str:'byu'; val2:$1A60; kind:REGJR ),
( str:'cmp'; val2:$1B00; kind:REGJR ),
( str:'inv'; val2:$1B40; kind:REGJR ),
( str:'gpo'; val2:$1C00; kind:REGJR ),
( str:'gfl'; val2:$1C40; kind:REGJR ),
( str:'stlw'; val2:$9200; kind:REGJR ),
( str:'ldlw'; val2:$9300; kind:REGJR ),
( str:'ppow'; val2:$9400; kind:REGJR ),
( str:'rodw'; val2:$9800; kind:REGJR ),
( str:'rouw'; val2:$9820; kind:REGJR ),
( str:'bidw'; val2:$9840; kind:REGJR ),
( str:'biuw'; val2:$9860; kind:REGJR ),
( str:'didw'; val2:$9A00; kind:REGJR ),
( str:'diuw'; val2:$9A20; kind:REGJR ),
( str:'bydw'; val2:$9A40; kind:REGJR ),
( str:'byuw'; val2:$9A60; kind:REGJR ),
( str:'cmpw'; val2:$9B00; kind:REGJR ),
( str:'invw'; val2:$9B40; kind:REGJR ),
( str:'gpow'; val2:$9C00; kind:REGJR ),
( str:'gflw'; val2:$9C40; kind:REGJR ),
{ single directly specified register | immediate byte }
( str:'sup'; val2:$DC00; kind:REGIM8 ),
( str:'sdn'; val2:$DD00; kind:REGIM8 ),
{ only immediate byte }
( str:'bups'; val2:$D800; kind:IM8 ),
( str:'bdns'; val2:$D900; kind:IM8 ),
{ single directly specified register with an optional relative jump |
immediate byte }
( str:'stl'; val2:$1200; kind:REGJRIM8 ),
( str:'ppo'; val2:$1400; kind:REGJRIM8 ),
( str:'pfl'; val2:$1440; kind:REGJRIM8 ),
{ single directly specified register, multibyte }
( str:'stlm'; val2:$D200; kind:REGM ),
( str:'ldlm'; val2:$D300; kind:REGM ),
( str:'ppom'; val2:$D400; kind:REGM ),
( str:'didm'; val2:$DA00; kind:REGM ),
( str:'dium'; val2:$DA20; kind:REGM ),
( str:'bydm'; val2:$DA40; kind:REGM ),
( str:'byum'; val2:$DA60; kind:REGM ),
( str:'cmpm'; val2:$DB00; kind:REGM ),
( str:'invm'; val2:$DB40; kind:REGM ),
( str:'phsm'; val2:$E600; kind:REGM ),
( str:'phum'; val2:$E700; kind:REGM ),
( str:'ppsm'; val2:$EE00; kind:REGM ),
( str:'ppum'; val2:$EF00; kind:REGM ),
{ first operand: directly specified register
second operand: directly or indirectly specified register |
immediate byte
optional third operand: relative jump }
( str:'anc'; val2:$0400; kind:AN_ARG ),
( str:'nac'; val2:$0500; kind:AN_ARG ),
( str:'orc'; val2:$0600; kind:AN_ARG ),
( str:'xrc'; val2:$0700; kind:AN_ARG ),
( str:'adb'; val2:$0A00; kind:AN_ARG ),
( str:'sbb'; val2:$0B00; kind:AN_ARG ),
( str:'an'; val2:$0C00; kind:AN_ARG ),
( str:'na'; val2:$0D00; kind:AN_ARG ),
( str:'or'; val2:$0E00; kind:AN_ARG ),
( str:'xr'; val2:$0F00; kind:AN_ARG ),
{ additional address mode
first operand: indexed, offset = directly or indirectly specified register
second operand: directly specified register }
( str:'adc'; val2:$0000; kind:AD_ARG ),
( str:'sbc'; val2:$0100; kind:AD_ARG ),
( str:'ad'; val2:$0800; kind:AD_ARG ),
( str:'sb'; val2:$0900; kind:AD_ARG ),
{ first operand: directly specified register
second operand: directly or indirectly specified register
optional third operand: relative jump }
( str:'ancw'; val2:$8400; kind:ANW_ARG ),
( str:'nacw'; val2:$8500; kind:ANW_ARG ),
( str:'orcw'; val2:$8600; kind:ANW_ARG ),
( str:'xrcw'; val2:$8700; kind:ANW_ARG ),
( str:'adbw'; val2:$8A00; kind:ANW_ARG ),
( str:'sbbw'; val2:$8B00; kind:ANW_ARG ),
( str:'anw'; val2:$8C00; kind:ANW_ARG ),
( str:'naw'; val2:$8D00; kind:ANW_ARG ),
( str:'orw'; val2:$8E00; kind:ANW_ARG ),
( str:'xrw'; val2:$8F00; kind:ANW_ARG ),
{ additional address mode
first operand: indexed, offset = directly or indirectly specified register
second operand: directly specified register }
( str:'adcw'; val2:$8000; kind:ADW_ARG ),
( str:'sbcw'; val2:$8100; kind:ADW_ARG ),
( str:'adw'; val2:$8800; kind:ADW_ARG ),
( str:'sbw'; val2:$8900; kind:ADW_ARG ),
{ first operand: directly specified register
second operand: directly or indirectly specified register
third operand: number of registers
optional fourth operand: relative jump }
( str:'adbcm'; val2:$C000; kind:ANM_ARG ),
( str:'sbbcm'; val2:$C100; kind:ANM_ARG ),
( str:'ancm'; val2:$C400; kind:ANM_ARG ),
( str:'nacm'; val2:$C500; kind:ANM_ARG ),
( str:'orcm'; val2:$C600; kind:ANM_ARG ),
( str:'xrcm'; val2:$C700; kind:ANM_ARG ),
( str:'anm'; val2:$CC00; kind:ANM_ARG ),
( str:'nam'; val2:$CD00; kind:ANM_ARG ),
( str:'orm'; val2:$CE00; kind:ANM_ARG ),
( str:'xrm'; val2:$CF00; kind:ANM_ARG ),
{ additional address mode
second operand: 5-bit immediate data }
( str:'adbm'; val2:$C800; kind:ADBM_ARG ),
( str:'sbbm'; val2:$C900; kind:ADBM_ARG ),
{ first operand: word size register
second operand: single directly specified register
third operand: optional relative jump }
( str:'gre'; val2:$9E00; kind:GRE_ARG ),
{ additional address mode
second operand: immediate word without an optional relative jump }
( str:'pre'; val2:$9600; kind:PRE_ARG ),
{ first operand: specific index register
second operand: directly specified register
optional third operand: relative jump }
( str:'gsr'; val2:$1D00; kind:GSR_ARG ),
( str:'gsrw'; val2:$9D00; kind:GSR_ARG ),
( str:'psrw'; val2:$9500; kind:GSR_ARG ),
{ additional address mode
second operand: immediate byte without an optional relative jump }
( str:'psr'; val2:$1500; kind:PSR_ARG ),
{ first operand: specific index register
second operand: directly specified register
third operand: number of registers }
( str:'psrm'; val2:$D500; kind:PSRM_ARG ),
{ first operand: status register
second operand: directly specified register
optional third operand: relative jump }
( str:'gst'; val2:$1E00; kind:GST_ARG ),
{ additional address mode
second operand: immediate byte without an optional relative jump }
( str:'pst'; val2:$1600; kind:PST_ARG ),
{ first operand: directly specified register
second operand: indexed, offset = directly or indirectly specified register }
( str:'stiw'; val2:$A200; kind:MOVEW ),
( str:'stdw'; val2:$A400; kind:MOVEW ),
( str:'ldiw'; val2:$AA00; kind:MOVEW ),
( str:'lddw'; val2:$AC00; kind:MOVEW ),
{ additional address mode: offset = immediate byte }
( str:'sti'; val2:$2200; kind:MOVEB ),
( str:'std'; val2:$2400; kind:MOVEB ),
( str:'ldi'; val2:$2A00; kind:MOVEB ),
( str:'ldd'; val2:$2C00; kind:MOVEB ),
{ first operand: directly specified register
second operand: indexed, offset = directly or indirectly specified register
third operand: number of registers }
( str:'stm'; val2:$E000; kind:MOVEM ),
( str:'stim'; val2:$E200; kind:MOVEM ),
( str:'stdm'; val2:$E400; kind:MOVEM ),
( str:'ldim'; val2:$EA00; kind:MOVEM ),
( str:'lddm'; val2:$EC00; kind:MOVEM ),
{ additional address mode
second operand: directly or indirectly specified register
third operand: number of registers
optional fourth operand: relative jump }
( str:'ldm'; val2:$E800; kind:LDM_ARG ),
{ first operand: directly specified register
second operand: various }
( str:'ld'; val2:$2800; kind:LD_ARG ),
( str:'ldw'; val2:$A800; kind:LDW_ARG ),
{ various operands }
( str:'st'; val2:$2000; kind:ST_ARG ),
( str:'stw'; val2:$A000; kind:STW_ARG ),
{ pseudo instruction }
( str:'db'; val2:ANYTHING; kind:DB_ARG )
);
NCC = 6; { index of the last item in the 'cctab' array }
{ table of conditional codes }
cctab: array[0..NCC] of tab = (
( str:'z'; val2:$0000; val1:ANYTHING ),
( str:'nc'; val2:$0100; val1:ANYTHING ),
( str:'lz'; val2:$0200; val1:ANYTHING ),
( str:'uz'; val2:$0300; val1:ANYTHING ),
( str:'nz'; val2:$0400; val1:ANYTHING ),
( str:'c'; val2:$0500; val1:ANYTHING ),
( str:'nlz'; val2:$0600; val1:ANYTHING )
);
NSREGS = 6; { index of the last item in the 'sregs' array }
{ table of status registers }
sregs: array[0..NSREGS] of tab = (
{ readable/writable registers }
( str:'pe'; val2:$0000; val1:ANYTHING ),
( str:'pd'; val2:$0020; val1:ANYTHING ),
( str:'ib'; val2:$0040; val1:ANYTHING ),
( str:'ua'; val2:$0060; val1:ANYTHING ),
( str:'ia'; val2:$0100; val1:ANYTHING ),
( str:'ie'; val2:$0120; val1:ANYTHING ),
{ read only register }
( str:'tm'; val2:$0160; val1:ANYTHING )
);
NWREGS = 5; { index of the last item in the 'wregs' array }
NIREGS = 1; { index of the last index register in the 'wregs' array }
{ table of word size registers, the first two are the index registers }
wregs: array[0..NWREGS] of tab = (
{ readable/writable registers }
( str:'ix'; val2:$0000; val1:ANYTHING ),
( str:'iz'; val2:$0040; val1:ANYTHING ),
( str:'iy'; val2:$0020; val1:ANYTHING ),
( str:'us'; val2:$0060; val1:ANYTHING ),
( str:'ss'; val2:$0100; val1:ANYTHING ),
{ read only register }
( str:'ky'; val2:$0160; val1:ANYTHING )
);
NSIR = 2; { index of the last item in the 'sirtab' array }
{ table of specific index registers }
sirtab: array[0..NSIR] of tab = (
( str:'sx'; val2:$0000; val1:ANYTHING ),
( str:'sy'; val2:$2000; val1:ANYTHING ),
( str:'sz'; val2:$4000; val1:ANYTHING )
);
{ compare the string 's' with the 'InBuf' at location 'InIndex' without
the case sensitivity,
update the 'InIndex' and return True if both string match }
function ParseString (s: string): boolean;
var
n: integer;
begin
ParseString := False;
if InIndex + Length(s) - 1 > Length(InBuf) then exit;
n := 0;
while n < Length(s) do
begin
if s[n+1] <> LowerCase(InBuf[InIndex + n]) then exit;
Inc (n);
end {while};
Inc (InIndex, n);
ParseString := True;
end {ParseString};
{ This function searches the table for a string pointed to by the InIndex,
and picks from the table the longest matching string.
Returns index to the table and updates InIndex when string found,
or leaves InIndex unchanged when not found. }
function ParseTable (
out x: integer; { returned index to the table }
var t: array of tab; { table to be searched }
last: integer { index of the last item }
) : boolean; { TRUE when string found }
var
maxindex, save, i: integer;
begin
maxindex := InIndex;
save := InIndex;
ParseTable := FALSE;
for i := 0 to last do
begin
InIndex := save;
if ParseString (t[i].str) and (InIndex > maxindex) then
begin
ParseTable := TRUE;
x := i;
maxindex := InIndex;
end {if};
end {for};
InIndex := maxindex;
end {ParseTable};
{ a specified character expected }
function ParseChar (c: char) : boolean;
begin
result := (InIndex <= Length(InBuf)) and (InBuf[InIndex] = c);
if result then Inc (InIndex);
end {ParseChar};
{ move the 'InIndex' to the first character different from space }
procedure SkipBlanks;
begin
while ParseChar (' ') do ;
end {SkipBlanks};
{ comma expected }
function ParseComma : boolean;
begin
SkipBlanks;
ParseComma := ParseChar (',');
SkipBlanks;
end {ParseComma};
{ optional jump/call/return condition }
function ParseCond (out x: word) : boolean;
var
i: integer;
begin
SkipBlanks;
if ParseTable (i, cctab, NCC) then
begin
x := cctab[i].val2;
ParseCond := TRUE;
end
else
begin
x := $0700;
ParseCond := FALSE;
end {if};
end {OptCond};
{ value of a hex digit }
function GetDigit (c: char) : integer;
const
digits: string[22] = '0123456789ABCDEFabcdef';
var
i: integer;
begin
i := 1;
while (i<=22) and (c <> digits[i]) do Inc (i);
if i>16 then GetDigit := i-7 else GetDigit := i-1;
end {GetDigit};
{ the function expects a number in base 'radix',
updates the InIndex }
function ParseNumber (out value: word; radix: word): boolean;
var
x, y: word;
begin
value := 0;
ParseNumber := FALSE;
while InIndex <= Length(InBuf) do
begin
x := word(GetDigit(InBuf[InIndex]));
if x >= radix then break; { stop when not a digit }
y := value*radix + x;
if y < value then break; { overflow, stop when too much digits }
value := y;
Inc (InIndex);
ParseNumber := TRUE;
end;
end {ParseNumber};
{ the function expects a hexadecimal (with a prefix &H) or decimal number
within specified range }
function EvalAndTest (out value: word; range: word) : boolean;
var
radix: word;
begin
EvalAndTest := FALSE;
SkipBlanks;
{ parse for the prefix of a hexadecimal numeral }
if ParseString ('&h') then radix := 16 else radix := 10;
if not ParseNumber (value, radix) then exit; { failure, missing number }
EvalAndTest := (value <= range); { FALSE when out of range }
end {EvalAndTest};
{ the function expects a main register,
returns the register index,
direct index in range $6000..$601F }
function RegArgum (out x: word) : boolean;
var
i: integer;
begin
RegArgum := FALSE;
SkipBlanks;
if not ParseChar ('$') then exit; { failure, invalid register }
if ParseTable (i, sirtab, NSIR) then
begin
RegArgum := TRUE;
x := sirtab[i].val2;
end
else
begin
RegArgum := ParseNumber (x, 10) and (x <= 31);
Inc (x,$6000);
end {if};
end {RegArgum};
{ expects a sign '+' or '-' }
function ParseSign (out x: word) : boolean;
begin
SkipBlanks;
x := PLUS;
ParseSign := TRUE;
if not ParseChar ('+') then
begin
x := MINUS;
ParseSign := ParseChar ('-');
end {if};
end {ParseSign};
{ expects the number of bytes for multibyte instructions }
function NumOfBytes (out x: word) : boolean;
begin
NumOfBytes := FALSE;
if not ParseComma then exit; { failure, comma expected }
if InIndex > Length(InBuf) then exit; { failure, digit expected }
x := word(GetDigit(InBuf[InIndex]));
if (x < 2) or (x > 8) then exit; { failure, digit out of range }
Inc (InIndex);
x := (x-1) shl 5;
NumOfBytes := TRUE;
end {NumOfBytes};
{ converts absolute address to relative displacement,
returns FALSE when out of range }
function AbsToRel (var destination: word; location: word) : boolean;
begin
Dec (destination,location);
if destination > $7FFF then destination := $0080 - destination;
AbsToRel := destination < $0100;
end {AbsToRel};
{ optional relative jump }
procedure OptRelJump;
var
x: word;
save: integer;
begin
SkipBlanks;
save := InIndex;
if ParseComma then
begin
ParseString ('jr'); { the 'JR' can be omitted }
if EvalAndTest (x, $FFFF) and
AbsToRel (x, loc + (word(OutIndex) shr wmd)) then
{ valid jump present }
begin
OutBuf[1] := OutBuf[1] xor $80;
OutIndex := OutIndex or wmd;
OutBuf[OutIndex] := byte(x);
Inc (OutIndex);
Exit;
end {if};
end {if};
{ jump absent or invalid }
InIndex := save;
end {OptRelJump};
{ assemble the instruction in the InBuf and place the result in the OutBuf,
on exit InIndex contains the position of an error (warning: it can point
past the end of the InBuf !), otherwise 0 }
procedure Assemble;
var
sign: word;
i, j: integer; { index to the tables }
kod: word; { opcode }
x1, x2, x3: word;
begin
InIndex := 1;
OutIndex := 0;
for i := 0 to 3 do OutBuf[i] := 0;
SkipBlanks; { skip leading blanks }
if (InIndex > Length(InBuf)) { empty InBuf? }
or ParseChar (';') then { comment? }
begin
InIndex := 0;
exit; { success }
end {if};
{ parse the mnemonic }
if not ParseTable (i, mnem, NMNEM) then exit;
{ failure, mnemonic not recognised }
kod := mnem[i].val2;
{ parse the arguments }
case mnem[i].kind of
INHERENT: { no operands }
begin
OutIndex := 1;
OutBuf[0] := Hi(kod);
end {case INHERENT};
RTN_ARG:
begin
ParseCond (x1);
OutIndex := 1;
OutBuf[0] := Hi(kod xor x1);
end {case RTN_ARG};
JR_ARG:
begin
if ParseCond (x1) and not ParseComma then exit; { failure }
if not EvalAndTest (x2, $FFFF) then exit; { failure }
if not AbsToRel (x2, loc + (1 shr wmd)) then exit; { failure }
OutIndex := 2;
OutBuf[0] := Hi(kod xor x1);
OutBuf[1] := byte(x2);
end {case JR_ARG};
CAL_ARG,
JP_ARG:
begin
SkipBlanks;
OutIndex := 2;
if (mnem[i].kind = JP_ARG) and ParseChar ('(') then
begin
if not RegArgum (x2) then exit; { failure, register expected }
if x2 < $6000 then exit; { failure, SIR not allowed }
if not ParseChar (')') then exit; { failure, ')' expected }
x1 := $EF00;
end
else if (mnem[i].kind = JP_ARG) and RegArgum (x2) then
begin
if x2 < $6000 then exit; { failure, SIR not allowed }
x1 := $EE00;
end
else
begin
if ParseCond (x1) and not ParseComma then exit; { failure }
if not EvalAndTest (x2, $FFFF) then exit; { failure }
Inc (OutIndex, 1 shl wmd);
end {if};
OutBuf[0] := Hi(kod xor x1);
OutBuf[1] := byte(x2);
OutBuf[2+wmd] := Hi(x2);
end {case CAL_ARG, JP_ARG};
REGISTER, { single directly specified register }
REGJR: { ...with an optional relative jump }
begin
if not RegArgum (x1) then exit; { failure, register expected }
if x1 < $6000 then exit; { failure, SIR not allowed }
OutIndex := 2;
OutBuf[0] := Hi(kod);
OutBuf[1] := byte(kod xor x1);
{ optional relative jump }
if mnem[i].kind = REGJR then OptRelJump;
end {case REGISTER, REGJR};
REGIM8, { single directly specified register | immediate byte }
IM8: { only immediate byte }
begin
{ register }
if (mnem[i].kind = REGIM8) and RegArgum (x1) then
begin
if x1 < $6000 then exit; { failure, SIR not allowed }
end
{ immediate byte }
else
begin
if not EvalAndTest (x1, $FF) then exit; { failure }
kod := kod xor $8000;
end {if};
OutIndex := 2;
OutBuf[0] := Hi(kod);
OutBuf[1] := byte(x1);
end {case REGIM8, IM8};
REGJRIM8:
begin
{ register }
if RegArgum (x1) then
begin
if x1 < $6000 then exit; { failure, SIR not allowed }
OutIndex := 2;
OutBuf[0] := Hi(kod);
OutBuf[1] := byte(kod xor x1);
{ optional relative jump }
OptRelJump;
end
{ immediate byte }
else
begin
if not EvalAndTest (x1, $FF) then exit; { failure }
kod := kod xor $4000;
if mnem[i].val2 = $1200 {STL opcode} then
OutIndex := 2 { STL }
else
OutIndex := 3; { PPO, PFL }
OutBuf[0] := Hi(kod);
OutBuf[1] := byte(kod);
OutBuf[OutIndex-1] := byte(x1);
end {if};
end {case REGJRIM8};
REGM: { single directly specified register, multibyte }
begin
if not RegArgum (x1) then exit; { failure, register expected }
if x1 < $6000 then exit; { failure, SIR not allowed }
if not NumOfBytes (x2) then exit; { failure, invalid number of bytes }
OutIndex := 3;
OutBuf[0] := Hi(kod);
OutBuf[1] := byte(kod xor x1);
OutBuf[2] := byte(x2);
end {case REGM};
AN_ARG,
AD_ARG,
ANW_ARG,
ADW_ARG:
begin
{ first operand: memory pointed to by an index register with an offset }
SkipBlanks;
if ParseChar ('(') then
begin
if not ParseTable (j, wregs, NIREGS) then exit;
{ failure, index register expected }
if not ParseSign (sign) then exit; { failure, sign expected }
if (kod and $0800) <> 0 then Dec (kod, $0600);
if (kod and $8000) <> 0 then Dec (kod, $4000);
kod := kod shl 1;
{ register as offset }
if RegArgum (x2) then
begin
if x2 < $6000 then OutIndex := 2 else OutIndex := 3;
kod := kod xor $3800;
end
{ immediate offset, supported only by byte size transfers }
else if (mnem[i].kind = AN_ARG) or (mnem[i].kind = AD_ARG) then
begin
if not EvalAndTest (x2, $FF) then exit;
kod := kod xor $7800;
OutIndex := 3;
end {if};
SkipBlanks;
if not ParseChar (')') then exit; { failure, ')' expected }
if not ParseComma then exit; { failure, comma expected }
{ second operand: directly specified register }
if not RegArgum (x1) then exit; { failure, register expected }
if x1 < $6000 then exit; { failure, SIR not allowed }
OutBuf[0] := Hi(kod) xor byte(j);
OutBuf[1] := byte(kod xor x1 xor sign) xor Hi(x2);
OutBuf[2] := byte(x2);
end
{ first operand: register }
else if RegArgum (x1) then
begin
if x1 < $6000 then exit; { failure, SIR not allowed }
if not ParseComma then exit; { failure, comma expected }
{ second operand: directly or indirectly specified register }
if RegArgum (x2) then
begin
if x2 < $6000 then OutIndex := 2 else OutIndex := 3;
end
{ second operand: immediate data, supported only by byte size transfers }
else if (mnem[i].kind = AN_ARG) or (mnem[i].kind = AD_ARG) then
begin
if not EvalAndTest (x2, $FF) then exit;
kod := kod xor $4000;
OutIndex := 3;
end {if};
OutBuf[0] := Hi(kod);
OutBuf[1] := byte(kod xor x1) xor Hi(x2);
OutBuf[2] := byte(x2);
{ optional relative jump }
OptRelJump;
end {if};
end {case AN_ARG, AD_ARG, ANW_ARG, ADW_ARG};
ANM_ARG,
ADBM_ARG:
begin
{ first operand: register }
if not RegArgum (x1) then exit; { failure, register expected }
if x1 < $6000 then exit; { failure, SIR not allowed }
if not ParseComma then exit; { failure, comma expected }
{ second operand: directly or indirectly specified register }
if RegArgum (x2) then
begin
end
{ second operand: 5-bit immediate data }
else if mnem[i].kind = ADBM_ARG then
begin
if not EvalAndTest (x2, $1F) then exit;
kod := kod xor $0200;
end {if};
{ third operand: number of bytes }
if not NumOfBytes (x3) then exit; { failure, invalid number of bytes }
OutIndex := 3;
OutBuf[0] := Hi(kod);
OutBuf[1] := byte(kod xor x1) xor Hi(x2);
OutBuf[2] := byte(x2 xor x3);
{ optional relative jump }
OptRelJump;
end {case ANM_ARG, ADBM_ARG};
GRE_ARG,
PRE_ARG:
begin
{ first operand: word size register }
SkipBlanks;
j := NWREGS;
if mnem[i].kind = PRE_ARG then Dec (j); { drop the read only reg. KY }
if not ParseTable (j, wregs, j) then exit; { failure }
kod := kod xor wregs[j].val2;
if not ParseComma then exit; { failure, comma expected }
{ second operand: register }
if RegArgum (x1) then
begin
if x1 < $6000 then exit; { failure, SIR not allowed }
OutIndex := 2;
OutBuf[0] := Hi(kod);
OutBuf[1] := byte(kod xor x1);
{ optional relative jump }
OptRelJump;
end
{ second operand: immediate word }
else if mnem[i].kind = PRE_ARG then
begin
if not EvalAndTest (x1, $FFFF) then exit; { failure }
kod := kod xor $4000;
OutIndex := 4;
OutBuf[0] := Hi(kod);
OutBuf[1] := byte(kod);
OutBuf[2] := byte(x1);
OutBuf[3] := Hi(x1);
end {if};
end {case GRE_ARG, PRE_ARG};
GSR_ARG,
PSR_ARG:
begin
{ first operand: specific index register }
SkipBlanks;
if not ParseTable (j, sirtab, NSIR) then exit; { failure }
x1 := sirtab[j].val2;
if not ParseComma then exit; { failure, comma expected }
{ second operand: register }
if RegArgum (x2) then
begin
if x2 < $6000 then exit; { failure, SIR not allowed }
OutIndex := 2;
OutBuf[0] := Hi(kod);
OutBuf[1] := byte(kod xor x2) xor Hi(x1);
{ optional relative jump }
OptRelJump;
end
{ second operand: immediate byte }
else if mnem[i].kind = PSR_ARG then
begin
if not EvalAndTest (x2, $1F) then exit; { failure }
kod := kod xor $4000;
OutIndex := 2;
OutBuf[0] := Hi(kod);
OutBuf[1] := byte(kod xor x2) xor Hi(x1);
end {if};
end {case GSR_ARG, PSR_ARG};
PSRM_ARG:
begin
{ first operand: specific index register }
SkipBlanks;
if not ParseTable (j, sirtab, NSIR) then exit; { failure }
x1 := sirtab[j].val2;
if not ParseComma then exit; { failure, comma expected }
{ second operand: register }
if not RegArgum (x2) then exit; { failure, register expected }
if x2 < $6000 then exit; { failure, SIR not allowed }
{ third operand: number of bytes }
if not NumOfBytes (x3) then exit; { failure, invalid number of bytes }
OutIndex := 3;
OutBuf[0] := Hi(kod);
OutBuf[1] := byte(kod xor x2) xor Hi(x1);
OutBuf[2] := byte(x3);
end {case PSRM_ARG};
GST_ARG,
PST_ARG:
begin
{ first operand: specific index register }
SkipBlanks;
j := NSREGS;
if mnem[i].kind = PST_ARG then Dec (j); { drop the read only reg. TM }
if not ParseTable (j, sregs, j) then exit; { failure }
kod := kod xor sregs[j].val2;
if not ParseComma then exit; { failure, comma expected }
{ second operand: register }
if RegArgum (x1) then
begin
if x1 < $6000 then exit; { failure, SIR not allowed }
OutIndex := 2;
OutBuf[0] := Hi(kod);
OutBuf[1] := byte(kod xor x1);
{ optional relative jump }
OptRelJump;
end
{ second operand: immediate byte }
else if mnem[i].kind = PST_ARG then
begin
if not EvalAndTest (x1, $FF) then exit; { failure }
kod := kod xor $4000;
OutIndex := 3;
OutBuf[0] := Hi(kod);
OutBuf[1] := byte(kod);
OutBuf[2] := byte(x1);
end {if};
end {case GST_ARG, PST_ARG};
MOVEB, { ldi, ldd, sti, std }
MOVEW: { ldiw, lddw, stiw, stdw }
begin
{ first operand: register }
if not RegArgum (x1) then exit; { failure, register expected }
if x1 < $6000 then exit; { failure, SIR not allowed }
if not ParseComma then exit; { failure, comma expected }
if not ParseChar ('(') then exit; { failure, '(' expected }
SkipBlanks;
{ second operand: memory pointed to by an index register with an offset }
if not ParseTable (j, wregs, NIREGS) then exit;
{ failure, index register expected }
if not ParseSign (sign) then exit; { failure, sign expected }
{ register as offset }
if RegArgum (x2) then
begin
if x2 < $6000 then OutIndex := 2 else OutIndex := 3;
end
{ immediate offset, supported only by byte size transfers }
else if mnem[i].kind = MOVEB then
begin
if not EvalAndTest (x2, $FF) then exit;
kod := kod xor $4000;
OutIndex := 3;
end {if};
SkipBlanks;
if not ParseChar (')') then exit; { failure, ')' expected }
OutBuf[0] := Hi(kod) xor byte(j);
OutBuf[1] := byte(kod xor x1 xor sign) xor Hi(x2);
OutBuf[2] := byte(x2);
end {case MOVEB, MOVEW};