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// license:BSD-3-Clause
// copyright-holders:Tatsuyuki Satoh
/*
Notice: please do not modify this file, except in case of compile- or critical emulation error
A more accurate implementation is in mame/alpha8201.*
cpu/alph8201/ will be removed soon
*/
/****************************************************************************
Alpha 8201/8301 Disassembler
Copyright Tatsuyuki Satoh
Originally written for the MAME project.
****************************************************************************/
#include "emu.h"
#include <ctype.h>
typedef unsigned char byte;
#define FMT(a,b) a, b
#define PTRS_PER_FORMAT 2
/****************************************************
8201 CONFIRMED OPCODES:
opcode mnemonic function flags
-------- ------------ ------------- -----
00000000 NOP - --
00000001 RORA ror A -C
00000010 ROLA rol A -C
00000011 INC RXB RXB+=2 ZC
00000100 DEC RXB RXB-=2 ZC (C=1 means No Borrow: RXB>=2)
00000101 INC A A++ ZC
00000110 DEC A A-- ZC (C=1 means No Borrow: A>=1)
00000110 CPL A A^=$FF --
00001aaa LD A,(IX0+i) A=[IX0+i] --
00010aaa LD A,(IX1+i) A=[IX1+i] --
00011aaa LD (IX2+i),A [IX2+i]=A --
00111aaa BIT R0.n ZF=R0 bit n Z-
0100aaa0 LD A,Rn A=Rn Z- [1]
0100aaa1 LD Rn,A Rn=A --
0101aaa0 ADD A,Rn A+=Rn ZC
0101aaa1 SUB A,Rn A-=Rn ZC (C=1 means No Borrow: A>=Rn)
0110aaa0 AND A,Rn A&=Rn Z-
0110aaa1 OR A,Rn A|=Rn Z-
0111aaaa ADD IX0,i IX0+=i --
1000aaaa ADD IX1,i IX1+=i --
1001aaaa ADD IX2,i IX2+=i --
1010aaaa LD RB,i RB=i -- Note: no bounds checking. Can set bank up to F.
1011-0aa LD MB,i set after-jump page
1011-1-- STOP
11000000 imm LD IX0,imm IX0=imm --
11000001 imm LD IX1,imm IX1=imm --
11000010 imm LD IX2,imm IX2=imm --
11000011 imm LD A,imm A=imm --
11000100 imm LD LP0,imm LP0=imm --
11000101 imm LD LP1,imm LP1=imm --
11000110 imm LD LP2,imm LP2=imm --
11000111 imm LD RXB,imm RXB=imm --
11001000 imm ADD A,imm A+=imm ZC
11001001 imm SUB A,imm A-=imm ZC (C=1 means No Borrow: A>=imm)
11001010 imm AND A,imm A&=imm Z-
11001011 imm OR A,imm A|=imm Z-
11001100 imm DJNZ LP0,imm LP0--,branch --
11001101 imm DJNZ LP1,imm LP1--,branch --
11001110 imm DJNZ LP2,imm LP2--,branch --
11001111 imm JNZ imm branch if !Z --
1101--00 imm JNC imm branch if !C --
1101--01 imm JZ imm branch if Z --
1101--1- imm J imm branch --
1110--xx mirror for the above
1111--xx mirror for the above
Notes:
[1] bug: the Z flag is not updated correctly after a LD A,Rn instruction. Fixed in 8302 (possibly 8301).
8302 CONFIRMED OPCODES:
----------------------
all of the 8201 ones, with stricter decoding for the following:
11010-00 imm JNC imm branch if !C --
11010-01 imm JZ imm branch if Z --
11010-1- imm J imm branch --
and these new opcodes:
opcode mnemonic function flags
-------- ------------ --------------- -----
11011000 imm LD A,(imm) A=MB:[imm] --
11011001 imm LD (imm),A MB:[imm]=A --
11011010 imm CMP A,imm temp=A-imm ZC
11011011 imm XOR A,imm A^=imm Z0
11011100 imm LD A,R(imm) A=reg(imm) --
11011101 imm LD R(imm),A reg(imm)=A --
11011110 imm JC imm branch if C --
11011111 imm CALL $xx save PC, branch --
11100000 EXG A,IX0 A<->IX0 --
11100001 EXG A,IX1 A<->IX1 --
11100010 EXG A,IX2 A<->IX2 --
11100011 EXG A,LP1 A<->LP1 --
11100100 EXG A,LP2 A<->LP2 --
11100101 EXG A,RXB A<->RXB --
11100110 EXG A,LP0 A<->LP0 --
11100111 EXG A,RB A<->RB --
11101000 LD IX0,A IX0=A --
11101001 LD IX1,A IX1=A --
11101010 LD IX2,A IX2=A --
11101011 LD LP1,A LP1=A --
11101100 LD LP2,A LP2=A --
11101101 LD RXB,A RXB=A --
11101110 LD LP0,A LP0=A --
11101111 LD RB,A RB=A --
11110000 EXG IX0,IX1 IX0<->IX1 --
11110001 EXG IX0,IX2 IX0<->IX2 --
11110010 REP LD (IX2),(RXB) equivalent to LD (IX2),(RXB); INC RXB; DJNZ LP0
11110011 REP LD (RXB),(IX0) equivalent to LD (RXB),(IX0); INC RXB; DJNZ LP0
11110100 SAVE ZC save ZC --
11110101 REST ZC restore ZC ZC
11110110 LD (RXB),A reg(RXB)=A --
11110111 LD A,(RXB) A=reg(RXB) --
11111000 CMP A,(RXB) temp=A-reg(RXB) ZC
11111001 XOR A,(RXB) A^=reg(RXB) Z0
11111010 ADD A,CF if (C) A++ ZC
11111011 SUB A,!CF if (!C) A-- ZC
11111100 TST A A==0? Z-
11111101 CLR A A=0 --
11111110 LD A,(IX0+A) A=[IX0+A] --
11111111 RET restore PC --
8303 CONFIRMED OPCODES:
----------------------
all of the 8302 ones, with stricter decoding for the following:
11010000 imm JNC imm branch if !C --
11010001 imm JZ imm branch if Z --
1101001- imm J imm branch --
additionally, this opcode is modified to support 11-bit instead of 10-bit
external addressing, this wasn't used in games however.
1011-0aa LD MB,i modified so that bit 3 is shifted to bit 2 before loading MB.
and these new opcodes are added:
110101--
11010100 imm LD A,(R77:$%02X)
11010101 imm LD (R77:$%02X),A
11010110 imm LD PC,(R77:$%02X) [1]
11010111 imm LD (R77:$%02X),PC [2]
Notes:
[1] appears to be LD PC,x in the disassembly, however it's LD LP0,x for kouyakyu
which uses a 8304, so the opcode was probably changed again.
[2] appears to be LD x,PC in the disassembly, however it's LD x,LP0 for hvoltage
which uses a 8304 (or 8404?), so the opcode was probably changed again.
****************************************************/
/****************************************************/
static const char *const Formats[] = {
FMT("0000_0000", "NOP"), // 00
FMT("0000_0001", "RRCA"), // 01
FMT("0000_0010", "RLCA"), // 02
FMT("0000_0011", "INC RXB"), // 03 : shougi $360 to $377; splndrbt
FMT("0000_0100", "DEC RXB"), // 04 : not found
FMT("0000_0101", "INC A"), // 05
FMT("0000_0110", "DEC A"), // 06
FMT("0000_0111", "CPL A"), // 07
FMT("0000_1aaa", "LD A,(IX0+%X)"), // 08-0F
FMT("0001_0aaa", "LD A,(IX1+%X)"), // 10-17
FMT("0001_1aaa", "LD (IX2+%X),A"), // 18-1F
FMT("0010_0aaa", "LD (RXB),(IX0+%X)"),// 20-27 : shougi $360 to $377
FMT("0010_1aaa", "LD (RXB),(IX1+%X)"),// 28-2f : not found
FMT("0011_0aaa", "LD (IX2+%X),(RXB)"),// 30-37 : not found
FMT("0011_1aaa", "BIT R0.%d"), // 38-3F ZF = R0.a (bit test)
FMT("0100_aaa0", "LD A,R%X"), // 40-4E
FMT("0100_aaa1", "LD R%X,A"), // 41-4F
FMT("0101_aaa0", "ADD A,R%X"), // 50-5E
FMT("0101_aaa1", "SUB A,R%X"), // 51-5F
FMT("0110_aaa0", "AND A,R%X"), // 60-6E
FMT("0110_aaa1", "OR A,R%X"), // 61-6F
FMT("0111_aaaa", "ADD IX0,$%X"), // 70-7f
FMT("1000_aaaa", "ADD IX1,$%X"), // 80-8f
FMT("1001_aaaa", "ADD IX2,$%X"), // 90-9f
FMT("1010_aaaa", "LD RB,%X"), // A0-AF
FMT("1011_x0aa", "LD MB,%X"), // B0-B3 (+ mirrors)
FMT("1011_x1xx", "STOP"), // B4 (+ mirrors)
FMT("1100_0000 I", "LD IX0,$%02X"), // C0
FMT("1100_0001 I", "LD IX1,$%02X"), // C1
FMT("1100_0010 I", "LD IX2,$%02X"), // C2
FMT("1100_0011 I", "LD A,$%02X"), // C3
FMT("1100_0100 I", "LD LP0,$%02X"), // C4
FMT("1100_0101 I", "LD LP1,$%02X"), // C5
FMT("1100_0110 I", "LD LP2,$%02X"), // C6
FMT("1100_0111 I", "LD RXB,$%02X"), // C7 : shougi, splndrbt, equites
FMT("1100_1000 I", "ADD A,$%02X"), // C8
FMT("1100_1001 I", "SUB A,$%02X"), // C9
FMT("1100_1010 I", "AND A,$%02X"), // CA
FMT("1100_1011 I", "OR A,$%02X"), // CB
FMT("1100_1100 I", "DJNZ LP0,$%02X"), // CC
FMT("1100_1101 I", "DJNZ LP1,$%02X"), // CD
FMT("1100_1110 I", "DJNZ LP2,$%02X"), // CE
FMT("1100_1111 I", "JNZ $%02X"), // CF
FMT("1101_0000 I", "JNC $%02X"), // D0
FMT("1101_0001 I", "JZ $%02X"), // D1
FMT("1101_001x I", "J $%02X"), // D2 (+ mirror)
/* -------------- 830x only ------------- */
FMT("1101_0100 I", "LD A,(R77:$%02X)"), // D4 : 8303+ only. exctscc2, bullfgtr
FMT("1101_0101 I", "LD (R77:$%02X),A"), // D5 : 8303+ only. exctscc2, bullfgtr, kouyakyu
FMT("1101_0110 I", "LD LP0,(R77:$%02X)"), // D6 : 8303+ only. kouyakyu
FMT("1101_0111 I", "LD (R77:$%02X),LP0"), // D7 : 8303+ only. hvoltage
FMT("1101_1000 I", "LD A,($%02X)"), // D8 : equites
FMT("1101_1001 I", "LD ($%02X),A"), // D9 : equites
FMT("1101_1010 I", "CMP A,$%02X"), // DA :
FMT("1101_1011 I", "XOR A,$%02X"), // DB : equites splndrbt
FMT("1101_1100 I", "LD A,R($%02X)"), // DC : not found
FMT("1101_1101 I", "LD R($%02X),A"), // DD : equites, splndrbt
FMT("1101_1110 I", "JC $%02X"), // DE : not found
FMT("1101_1111 I", "CALL $%02X"), // DF :
FMT("1110_0000", "EXG A,IX0"), // E0 : exctsccr
FMT("1110_0001", "EXG A,IX1"), // E1 : not found
FMT("1110_0010", "EXG A,IX2"), // E2 : not found
FMT("1110_0011", "EXG A,LP1"), // E3 : exctsccr in pair with EB
FMT("1110_0100", "EXG A,LP2"), // E4 : not found
FMT("1110_0101", "EXG A,RXB"), // E5 : splndrbt
FMT("1110_0110", "EXG A,LP0"), // E6 : splndrbt, bullfgtr, kouyakyu. EXG, not LD: see splndrbt $3ba to $3d3
FMT("1110_0111", "EXG A,RB"), // E7 : not found
FMT("1110_1000", "LD IX0,A"), // E8 :
FMT("1110_1001", "LD IX1,A"), // E9 : not found
FMT("1110_1010", "LD IX2,A"), // EA :
FMT("1110_1011", "LD LP1,A"), // EB : exctsccr in pair with E3
FMT("1110_1100", "LP LP2,A"), // EC : not found
FMT("1110_1101", "LD RXB,A"), // ED : splndrbt
FMT("1110_1110", "LD LP0,A"), // EE : splndrbt, bullfgtr
FMT("1110_1111", "LD RB,A"), // EF : not found
FMT("1111_0000", "EXG IX0,IX1"), // F0 : not found
FMT("1111_0001", "EXG IX0,IX2"), // F1 : splndrbt $2e to $38, equites $40 to $4a
FMT("1111_0010", "REP LD (IX2),(RXB)"),// F2 : splndrbt LD (IX2),(RXB); INC RXB; DJNZ LP0
FMT("1111_0011", "REP LD (RXB),(IX0)"),// F3 : not found LD (RXB),(IX0); INC RXB; DJNZ LP0
FMT("1111_0100", "SAVE ZC"), // F4 : not found
FMT("1111_0101", "REST ZC"), // F5 : not found
FMT("1111_0110", "LD (RXB),A"), // F6 : exctsccr
FMT("1111_0111", "LD A,(RXB)"), // F7 : not found
FMT("1111_1000", "CMP A,(RXB)"), // F8 : exctsccr
FMT("1111_1001", "XOR A,(RXB)"), // F9 : exctsccr
FMT("1111_1010", "ADD A,CF"), // FA :
FMT("1111_1011", "SUB A,!CF"), // FB : not found
FMT("1111_1100", "TST A"), // FC :
FMT("1111_1101", "CLR A"), // FD :
FMT("1111_1110", "LD A,(IX0+A)"), // FE :
FMT("1111_1111", "RET"), // FF :
nullptr
};
#define MAX_OPS ((ARRAY_LENGTH(Formats) - 1) / PTRS_PER_FORMAT)
struct AD8201Opcode {
byte mask;
byte bits;
byte type;
byte pmask;
byte pdown;
const char *fmt;
};
static AD8201Opcode Op[MAX_OPS+1];
static int OpInizialized = 0;
static void InitDasm8201(void)
{
const char *p;
byte mask, bits;
int bit;
int i;
char chr , type;
int pmask , pdown;
for(i=0;(p=Formats[i*2])!=nullptr;i++)
{
mask = 0;
bits = 0;
pmask = 0;
pdown = 0;
type = 0;
bit = 7;
while (*p && bit >= 0) {
chr = *p++;
switch (chr) {
case '1': bits |= 1<<bit;
case '0': mask |= 1<<bit; bit--; break;
#if 0
case 'b':
type |= 0x80;
#endif
case 'a':
pmask |= 1<<bit;
pdown = bit;
case 'x':
bit --;
break;
case '_':
continue;
default:
fatalerror("Invalid instruction encoding '%s %s'\n", Formats[i*2],Formats[i*2+1]);
}
}
if (bit != -1 ) {
fatalerror("not enough bits in encoding '%s %s' %d\n", Formats[i*2],Formats[i*2+1],bit);
}
Op[i].mask = mask;
Op[i].bits = bits;
Op[i].pmask = pmask;
Op[i].pdown = pdown;
Op[i].fmt = Formats[i*2+1];
Op[i].type = type;
/* 2 byte code ? */
while (isspace((UINT8)*p)) p++;
if( (*p) )
Op[i].type |= 0x10;
/* number of param */
if( (p=strchr(Op[i].fmt,'%'))!=nullptr )
{
Op[i].type |= 0x01; /* single param */
if(strchr(p+1,'%') )
Op[i].type |= 0x02; /* double param */
}
}
OpInizialized = 1;
}
CPU_DISASSEMBLE( alpha8201 )
{
offs_t dasmflags = 0;
int i;
int op;
int cnt = 1;
int code , disp;
if (!OpInizialized) InitDasm8201();
code = oprom[0];
op = -1; /* no matching opcode */
for ( i = 0; i < MAX_OPS; i++)
{
if( (code & Op[i].mask) == Op[i].bits )
{
if (op != -1)
{
fprintf(stderr, "Error: opcode %02X matches %d (%s) and %d (%s)\n",
code,i,Op[i].fmt,op,Op[op].fmt);
}
op = i;
}
}
if (op == -1)
{
sprintf(buffer,"db %2.2x",code);
return cnt;
}
if (Op[op].type & 0x10)
{
disp = opram[1];
cnt++;
}
else
{
disp = (code & Op[op].pmask) >> Op[op].pdown;
}
if (Op[op].type & 0x02)
sprintf(buffer, Op[op].fmt,disp,disp);
else if (Op[op].type & 0x01)
sprintf(buffer, Op[op].fmt,disp);
else
sprintf(buffer, "%s",Op[op].fmt);
switch (code)
{
case 0xcc:
case 0xcd:
case 0xce:
case 0xdf:
dasmflags = DASMFLAG_STEP_OVER;
break;
case 0xff:
dasmflags = DASMFLAG_STEP_OUT;
break;
}
return cnt | dasmflags | DASMFLAG_SUPPORTED;
}
|