ref: b1b1871fb7888dbe050e4a120b82f9f6b701547c
dir: /snes/spc.c/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <stdbool.h>
#include <stddef.h>
#include "spc.h"
#include "apu.h"
static const int cyclesPerOpcode[256] = {
2, 8, 4, 5, 3, 4, 3, 6, 2, 6, 5, 4, 5, 4, 6, 8,
2, 8, 4, 5, 4, 5, 5, 6, 5, 5, 6, 5, 2, 2, 4, 6,
2, 8, 4, 5, 3, 4, 3, 6, 2, 6, 5, 4, 5, 4, 5, 4,
2, 8, 4, 5, 4, 5, 5, 6, 5, 5, 6, 5, 2, 2, 3, 8,
2, 8, 4, 5, 3, 4, 3, 6, 2, 6, 4, 4, 5, 4, 6, 6,
2, 8, 4, 5, 4, 5, 5, 6, 5, 5, 4, 5, 2, 2, 4, 3,
2, 8, 4, 5, 3, 4, 3, 6, 2, 6, 4, 4, 5, 4, 5, 5,
2, 8, 4, 5, 4, 5, 5, 6, 5, 5, 5, 5, 2, 2, 3, 6,
2, 8, 4, 5, 3, 4, 3, 6, 2, 6, 5, 4, 5, 2, 4, 5,
2, 8, 4, 5, 4, 5, 5, 6, 5, 5, 5, 5, 2, 2, 12,5,
2, 8, 4, 5, 3, 4, 3, 6, 2, 6, 4, 4, 5, 2, 4, 4,
2, 8, 4, 5, 4, 5, 5, 6, 5, 5, 5, 5, 2, 2, 3, 4,
2, 8, 4, 5, 4, 5, 4, 7, 2, 5, 6, 4, 5, 2, 4, 9,
2, 8, 4, 5, 5, 6, 6, 7, 4, 5, 5, 5, 2, 2, 6, 3,
2, 8, 4, 5, 3, 4, 3, 6, 2, 4, 5, 3, 4, 3, 4, 3,
2, 8, 4, 5, 4, 5, 5, 6, 3, 4, 5, 4, 2, 2, 4, 3
};
static uint8_t spc_read(Spc* spc, uint16_t adr);
static void spc_write(Spc* spc, uint16_t adr, uint8_t val);
static uint8_t spc_readOpcode(Spc* spc);
static uint16_t spc_readOpcodeWord(Spc* spc);
static uint8_t spc_getFlags(Spc* spc);
static void spc_setFlags(Spc* spc, uint8_t value);
static void spc_setZN(Spc* spc, uint8_t value);
static void spc_doBranch(Spc* spc, uint8_t value, bool check);
static uint8_t spc_pullByte(Spc* spc);
static void spc_pushByte(Spc* spc, uint8_t value);
static uint16_t spc_pullWord(Spc* spc);
static void spc_pushWord(Spc* spc, uint16_t value);
static uint16_t spc_readWord(Spc* spc, uint16_t adrl, uint16_t adrh);
static void spc_writeWord(Spc* spc, uint16_t adrl, uint16_t adrh, uint16_t value);
static void spc_doOpcode(Spc* spc, uint8_t opcode);
// addressing modes and opcode functions not declared, only used after defintions
static uint8_t spc_read(Spc* spc, uint16_t adr) {
return apu_cpuRead(spc->apu, adr);
}
static void spc_write(Spc* spc, uint16_t adr, uint8_t val) {
if (0 && adr == 0x5e)
printf("writing to vol_dirty %d\n", val);
apu_cpuWrite(spc->apu, adr, val);
}
Spc* spc_init(Apu* apu) {
Spc* spc = (Spc * )malloc(sizeof(Spc));
spc->apu = apu;
return spc;
}
void spc_free(Spc* spc) {
free(spc);
}
void spc_reset(Spc* spc) {
spc->a = 0;
spc->x = 0;
spc->y = 0;
spc->sp = 0;
spc->pc = spc_read(spc, 0xfffe) | (spc_read(spc, 0xffff) << 8);
spc->c = false;
spc->z = false;
spc->v = false;
spc->n = false;
spc->i = false;
spc->h = false;
spc->p = false;
spc->b = false;
spc->stopped = false;
spc->cyclesUsed = 0;
}
void spc_saveload(Spc *spc, SaveLoadFunc *func, void *ctx) {
func(ctx, &spc->a, offsetof(Spc, cyclesUsed) - offsetof(Spc, a));
}
int spc_runOpcode(Spc* spc) {
spc->cyclesUsed = 0;
if(spc->stopped) return 1;
uint8_t opcode = spc_readOpcode(spc);
spc->cyclesUsed = cyclesPerOpcode[opcode];
spc_doOpcode(spc, opcode);
return spc->cyclesUsed;
}
static uint8_t spc_readOpcode(Spc* spc) {
return spc_read(spc, spc->pc++);
}
static uint16_t spc_readOpcodeWord(Spc* spc) {
uint8_t low = spc_readOpcode(spc);
return low | (spc_readOpcode(spc) << 8);
}
static uint8_t spc_getFlags(Spc* spc) {
uint8_t val = spc->n << 7;
val |= spc->v << 6;
val |= spc->p << 5;
val |= spc->b << 4;
val |= spc->h << 3;
val |= spc->i << 2;
val |= spc->z << 1;
val |= (uint8_t)spc->c;
return val;
}
static void spc_setFlags(Spc* spc, uint8_t val) {
spc->n = val & 0x80;
spc->v = val & 0x40;
spc->p = val & 0x20;
spc->b = val & 0x10;
spc->h = val & 8;
spc->i = val & 4;
spc->z = val & 2;
spc->c = val & 1;
}
static void spc_setZN(Spc* spc, uint8_t value) {
spc->z = value == 0;
spc->n = value & 0x80;
}
static void spc_doBranch(Spc* spc, uint8_t value, bool check) {
if(check) {
spc->cyclesUsed += 2; // taken branch: 2 extra cycles
spc->pc += (int8_t) value;
}
}
static uint8_t spc_pullByte(Spc* spc) {
spc->sp++;
return spc_read(spc, 0x100 | spc->sp);
}
static void spc_pushByte(Spc* spc, uint8_t value) {
spc_write(spc, 0x100 | spc->sp, value);
spc->sp--;
}
static uint16_t spc_pullWord(Spc* spc) {
uint8_t value = spc_pullByte(spc);
return value | (spc_pullByte(spc) << 8);
}
static void spc_pushWord(Spc* spc, uint16_t value) {
spc_pushByte(spc, value >> 8);
spc_pushByte(spc, value & 0xff);
}
static uint16_t spc_readWord(Spc* spc, uint16_t adrl, uint16_t adrh) {
uint8_t value = spc_read(spc, adrl);
return value | (spc_read(spc, adrh) << 8);
}
static void spc_writeWord(Spc* spc, uint16_t adrl, uint16_t adrh, uint16_t value) {
spc_write(spc, adrl, value & 0xff);
spc_write(spc, adrh, value >> 8);
}
// adressing modes
static uint16_t spc_adrDp(Spc* spc) {
return spc_readOpcode(spc) | (spc->p << 8);
}
static uint16_t spc_adrAbs(Spc* spc) {
return spc_readOpcodeWord(spc);
}
static uint16_t spc_adrInd(Spc* spc) {
return spc->x | (spc->p << 8);
}
static uint16_t spc_adrIdx(Spc* spc) {
uint8_t pointer = spc_readOpcode(spc);
return spc_readWord(spc, ((pointer + spc->x) & 0xff) | (spc->p << 8), ((pointer + spc->x + 1) & 0xff) | (spc->p << 8));
}
static uint16_t spc_adrImm(Spc* spc) {
return spc->pc++;
}
static uint16_t spc_adrDpx(Spc* spc) {
return ((spc_readOpcode(spc) + spc->x) & 0xff) | (spc->p << 8);
}
static uint16_t spc_adrDpy(Spc* spc) {
return ((spc_readOpcode(spc) + spc->y) & 0xff) | (spc->p << 8);
}
static uint16_t spc_adrAbx(Spc* spc) {
return (spc_readOpcodeWord(spc) + spc->x) & 0xffff;
}
static uint16_t spc_adrAby(Spc* spc) {
return (spc_readOpcodeWord(spc) + spc->y) & 0xffff;
}
static uint16_t spc_adrIdy(Spc* spc) {
uint8_t pointer = spc_readOpcode(spc);
uint16_t adr = spc_readWord(spc, pointer | (spc->p << 8), ((pointer + 1) & 0xff) | (spc->p << 8));
return (adr + spc->y) & 0xffff;
}
static uint16_t spc_adrDpDp(Spc* spc, uint16_t* src) {
*src = spc_readOpcode(spc) | (spc->p << 8);
return spc_readOpcode(spc) | (spc->p << 8);
}
static uint16_t spc_adrDpImm(Spc* spc, uint16_t* src) {
*src = spc->pc++;
return spc_readOpcode(spc) | (spc->p << 8);
}
static uint16_t spc_adrIndInd(Spc* spc, uint16_t* src) {
*src = spc->y | (spc->p << 8);
return spc->x | (spc->p << 8);
}
static uint8_t spc_adrAbsBit(Spc* spc, uint16_t* adr) {
uint16_t adrBit = spc_readOpcodeWord(spc);
*adr = adrBit & 0x1fff;
return adrBit >> 13;
}
static uint16_t spc_adrDpWord(Spc* spc, uint16_t* low) {
uint8_t adr = spc_readOpcode(spc);
*low = adr | (spc->p << 8);
return ((adr + 1) & 0xff) | (spc->p << 8);
}
static uint16_t spc_adrIndP(Spc* spc) {
return spc->x++ | (spc->p << 8);
}
// opcode functions
static void spc_and(Spc* spc, uint16_t adr) {
spc->a &= spc_read(spc, adr);
spc_setZN(spc, spc->a);
}
static void spc_andm(Spc* spc, uint16_t dst, uint16_t src) {
uint8_t value = spc_read(spc, src);
uint8_t result = spc_read(spc, dst) & value;
spc_write(spc, dst, result);
spc_setZN(spc, result);
}
static void spc_or(Spc* spc, uint16_t adr) {
spc->a |= spc_read(spc, adr);
spc_setZN(spc, spc->a);
}
static void spc_orm(Spc* spc, uint16_t dst, uint16_t src) {
uint8_t value = spc_read(spc, src);
uint8_t result = spc_read(spc, dst) | value;
spc_write(spc, dst, result);
spc_setZN(spc, result);
}
static void spc_eor(Spc* spc, uint16_t adr) {
spc->a ^= spc_read(spc, adr);
spc_setZN(spc, spc->a);
}
static void spc_eorm(Spc* spc, uint16_t dst, uint16_t src) {
uint8_t value = spc_read(spc, src);
uint8_t result = spc_read(spc, dst) ^ value;
spc_write(spc, dst, result);
spc_setZN(spc, result);
}
static void spc_adc(Spc* spc, uint16_t adr) {
uint8_t value = spc_read(spc, adr);
int result = spc->a + value + spc->c;
spc->v = (spc->a & 0x80) == (value & 0x80) && (value & 0x80) != (result & 0x80);
spc->h = ((spc->a & 0xf) + (value & 0xf) + spc->c) > 0xf;
spc->c = result > 0xff;
spc->a = result;
spc_setZN(spc, spc->a);
}
static void spc_adcm(Spc* spc, uint16_t dst, uint16_t src) {
uint8_t value = spc_read(spc, src);
uint8_t applyOn = spc_read(spc, dst);
int result = applyOn + value + spc->c;
spc->v = (applyOn & 0x80) == (value & 0x80) && (value & 0x80) != (result & 0x80);
spc->h = ((applyOn & 0xf) + (value & 0xf) + spc->c) > 0xf;
spc->c = result > 0xff;
spc_write(spc, dst, result);
spc_setZN(spc, result);
}
static void spc_sbc(Spc* spc, uint16_t adr) {
uint8_t value = spc_read(spc, adr) ^ 0xff;
int result = spc->a + value + spc->c;
spc->v = (spc->a & 0x80) == (value & 0x80) && (value & 0x80) != (result & 0x80);
spc->h = ((spc->a & 0xf) + (value & 0xf) + spc->c) > 0xf;
spc->c = result > 0xff;
spc->a = result;
spc_setZN(spc, spc->a);
}
static void spc_sbcm(Spc* spc, uint16_t dst, uint16_t src) {
uint8_t value = spc_read(spc, src) ^ 0xff;
uint8_t applyOn = spc_read(spc, dst);
int result = applyOn + value + spc->c;
spc->v = (applyOn & 0x80) == (value & 0x80) && (value & 0x80) != (result & 0x80);
spc->h = ((applyOn & 0xf) + (value & 0xf) + spc->c) > 0xf;
spc->c = result > 0xff;
spc_write(spc, dst, result);
spc_setZN(spc, result);
}
static void spc_cmp(Spc* spc, uint16_t adr) {
uint8_t value = spc_read(spc, adr) ^ 0xff;
int result = spc->a + value + 1;
spc->c = result > 0xff;
spc_setZN(spc, result);
}
static void spc_cmpx(Spc* spc, uint16_t adr) {
uint8_t value = spc_read(spc, adr) ^ 0xff;
int result = spc->x + value + 1;
spc->c = result > 0xff;
spc_setZN(spc, result);
}
static void spc_cmpy(Spc* spc, uint16_t adr) {
uint8_t value = spc_read(spc, adr) ^ 0xff;
int result = spc->y + value + 1;
spc->c = result > 0xff;
spc_setZN(spc, result);
}
static void spc_cmpm(Spc* spc, uint16_t dst, uint16_t src) {
uint8_t value = spc_read(spc, src) ^ 0xff;
int result = spc_read(spc, dst) + value + 1;
spc->c = result > 0xff;
spc_setZN(spc, result);
}
static void spc_mov(Spc* spc, uint16_t adr) {
spc->a = spc_read(spc, adr);
spc_setZN(spc, spc->a);
}
static void spc_movx(Spc* spc, uint16_t adr) {
spc->x = spc_read(spc, adr);
spc_setZN(spc, spc->x);
}
static void spc_movy(Spc* spc, uint16_t adr) {
spc->y = spc_read(spc, adr);
spc_setZN(spc, spc->y);
}
static void spc_movs(Spc* spc, uint16_t adr) {
spc_read(spc, adr);
spc_write(spc, adr, spc->a);
}
static void spc_movsx(Spc* spc, uint16_t adr) {
spc_read(spc, adr);
spc_write(spc, adr, spc->x);
}
static void spc_movsy(Spc* spc, uint16_t adr) {
spc_read(spc, adr);
spc_write(spc, adr, spc->y);
}
static void spc_asl(Spc* spc, uint16_t adr) {
uint8_t val = spc_read(spc, adr);
spc->c = val & 0x80;
val <<= 1;
spc_write(spc, adr, val);
spc_setZN(spc, val);
}
static void spc_lsr(Spc* spc, uint16_t adr) {
uint8_t val = spc_read(spc, adr);
spc->c = val & 1;
val >>= 1;
spc_write(spc, adr, val);
spc_setZN(spc, val);
}
static void spc_rol(Spc* spc, uint16_t adr) {
uint8_t val = spc_read(spc, adr);
bool newC = val & 0x80;
val = (val << 1) | (uint8_t)spc->c;
spc->c = newC;
spc_write(spc, adr, val);
spc_setZN(spc, val);
}
static void spc_ror(Spc* spc, uint16_t adr) {
uint8_t val = spc_read(spc, adr);
bool newC = val & 1;
val = (val >> 1) | (spc->c << 7);
spc->c = newC;
spc_write(spc, adr, val);
spc_setZN(spc, val);
}
static void spc_inc(Spc* spc, uint16_t adr) {
uint8_t val = spc_read(spc, adr) + 1;
spc_write(spc, adr, val);
spc_setZN(spc, val);
}
static void spc_dec(Spc* spc, uint16_t adr) {
uint8_t val = spc_read(spc, adr) - 1;
spc_write(spc, adr, val);
spc_setZN(spc, val);
}
static void spc_doOpcode(Spc* spc, uint8_t opcode) {
switch(opcode) {
case 0x00: { // nop imp
// no operation
break;
}
case 0x01:
case 0x11:
case 0x21:
case 0x31:
case 0x41:
case 0x51:
case 0x61:
case 0x71:
case 0x81:
case 0x91:
case 0xa1:
case 0xb1:
case 0xc1:
case 0xd1:
case 0xe1:
case 0xf1: { // tcall imp
spc_pushWord(spc, spc->pc);
uint16_t adr = 0xffde - (2 * (opcode >> 4));
spc->pc = spc_readWord(spc, adr, adr + 1);
break;
}
case 0x02:
case 0x22:
case 0x42:
case 0x62:
case 0x82:
case 0xa2:
case 0xc2:
case 0xe2: { // set1 dp
uint16_t adr = spc_adrDp(spc);
spc_write(spc, adr, spc_read(spc, adr) | (1 << (opcode >> 5)));
break;
}
case 0x12:
case 0x32:
case 0x52:
case 0x72:
case 0x92:
case 0xb2:
case 0xd2:
case 0xf2: { // clr1 dp
uint16_t adr = spc_adrDp(spc);
spc_write(spc, adr, spc_read(spc, adr) & ~(1 << (opcode >> 5)));
break;
}
case 0x03:
case 0x23:
case 0x43:
case 0x63:
case 0x83:
case 0xa3:
case 0xc3:
case 0xe3: { // bbs dp, rel
uint8_t val = spc_read(spc, spc_adrDp(spc));
spc_doBranch(spc, spc_readOpcode(spc), val & (1 << (opcode >> 5)));
break;
}
case 0x13:
case 0x33:
case 0x53:
case 0x73:
case 0x93:
case 0xb3:
case 0xd3:
case 0xf3: { // bbc dp, rel
uint8_t val = spc_read(spc, spc_adrDp(spc));
spc_doBranch(spc, spc_readOpcode(spc), (val & (1 << (opcode >> 5))) == 0);
break;
}
case 0x04: { // or dp
spc_or(spc, spc_adrDp(spc));
break;
}
case 0x05: { // or abs
spc_or(spc, spc_adrAbs(spc));
break;
}
case 0x06: { // or ind
spc_or(spc, spc_adrInd(spc));
break;
}
case 0x07: { // or idx
spc_or(spc, spc_adrIdx(spc));
break;
}
case 0x08: { // or imm
spc_or(spc, spc_adrImm(spc));
break;
}
case 0x09: { // orm dp, dp
uint16_t src = 0;
uint16_t dst = spc_adrDpDp(spc, &src);
spc_orm(spc, dst, src);
break;
}
case 0x0a: { // or1 abs.bit
uint16_t adr = 0;
uint8_t bit = spc_adrAbsBit(spc, &adr);
spc->c = spc->c | ((spc_read(spc, adr) >> bit) & 1);
break;
}
case 0x0b: { // asl dp
spc_asl(spc, spc_adrDp(spc));
break;
}
case 0x0c: { // asl abs
spc_asl(spc, spc_adrAbs(spc));
break;
}
case 0x0d: { // pushp imp
spc_pushByte(spc, spc_getFlags(spc));
break;
}
case 0x0e: { // tset1 abs
uint16_t adr = spc_adrAbs(spc);
uint8_t val = spc_read(spc, adr);
uint8_t result = spc->a + (val ^ 0xff) + 1;
spc_setZN(spc, result);
spc_write(spc, adr, val | spc->a);
break;
}
case 0x0f: { // brk imp
spc_pushWord(spc, spc->pc);
spc_pushByte(spc, spc_getFlags(spc));
spc->i = false;
spc->b = true;
spc->pc = spc_readWord(spc, 0xffde, 0xffdf);
break;
}
case 0x10: { // bpl rel
spc_doBranch(spc, spc_readOpcode(spc), !spc->n);
break;
}
case 0x14: { // or dpx
spc_or(spc, spc_adrDpx(spc));
break;
}
case 0x15: { // or abx
spc_or(spc, spc_adrAbx(spc));
break;
}
case 0x16: { // or aby
spc_or(spc, spc_adrAby(spc));
break;
}
case 0x17: { // or idy
spc_or(spc, spc_adrIdy(spc));
break;
}
case 0x18: { // orm dp, imm
uint16_t src = 0;
uint16_t dst = spc_adrDpImm(spc, &src);
spc_orm(spc, dst, src);
break;
}
case 0x19: { // orm ind, ind
uint16_t src = 0;
uint16_t dst = spc_adrIndInd(spc, &src);
spc_orm(spc, dst, src);
break;
}
case 0x1a: { // decw dp
uint16_t low = 0;
uint16_t high = spc_adrDpWord(spc, &low);
uint16_t value = spc_readWord(spc, low, high) - 1;
spc->z = value == 0;
spc->n = value & 0x8000;
spc_writeWord(spc, low, high, value);
break;
}
case 0x1b: { // asl dpx
spc_asl(spc, spc_adrDpx(spc));
break;
}
case 0x1c: { // asla imp
spc->c = spc->a & 0x80;
spc->a <<= 1;
spc_setZN(spc, spc->a);
break;
}
case 0x1d: { // decx imp
spc->x--;
spc_setZN(spc, spc->x);
break;
}
case 0x1e: { // cmpx abs
spc_cmpx(spc, spc_adrAbs(spc));
break;
}
case 0x1f: { // jmp iax
uint16_t pointer = spc_readOpcodeWord(spc);
spc->pc = spc_readWord(spc, (pointer + spc->x) & 0xffff, (pointer + spc->x + 1) & 0xffff);
break;
}
case 0x20: { // clrp imp
spc->p = false;
break;
}
case 0x24: { // and dp
spc_and(spc, spc_adrDp(spc));
break;
}
case 0x25: { // and abs
spc_and(spc, spc_adrAbs(spc));
break;
}
case 0x26: { // and ind
spc_and(spc, spc_adrInd(spc));
break;
}
case 0x27: { // and idx
spc_and(spc, spc_adrIdx(spc));
break;
}
case 0x28: { // and imm
spc_and(spc, spc_adrImm(spc));
break;
}
case 0x29: { // andm dp, dp
uint16_t src = 0;
uint16_t dst = spc_adrDpDp(spc, &src);
spc_andm(spc, dst, src);
break;
}
case 0x2a: { // or1n abs.bit
uint16_t adr = 0;
uint8_t bit = spc_adrAbsBit(spc, &adr);
spc->c = spc->c | (~(spc_read(spc, adr) >> bit) & 1);
break;
}
case 0x2b: { // rol dp
spc_rol(spc, spc_adrDp(spc));
break;
}
case 0x2c: { // rol abs
spc_rol(spc, spc_adrAbs(spc));
break;
}
case 0x2d: { // pusha imp
spc_pushByte(spc, spc->a);
break;
}
case 0x2e: { // cbne dp, rel
uint8_t val = spc_read(spc, spc_adrDp(spc)) ^ 0xff;
uint8_t result = spc->a + val + 1;
spc_doBranch(spc, spc_readOpcode(spc), result != 0);
break;
}
case 0x2f: { // bra rel
spc->pc += (int8_t) spc_readOpcode(spc);
break;
}
case 0x30: { // bmi rel
spc_doBranch(spc, spc_readOpcode(spc), spc->n);
break;
}
case 0x34: { // and dpx
spc_and(spc, spc_adrDpx(spc));
break;
}
case 0x35: { // and abx
spc_and(spc, spc_adrAbx(spc));
break;
}
case 0x36: { // and aby
spc_and(spc, spc_adrAby(spc));
break;
}
case 0x37: { // and idy
spc_and(spc, spc_adrIdy(spc));
break;
}
case 0x38: { // andm dp, imm
uint16_t src = 0;
uint16_t dst = spc_adrDpImm(spc, &src);
spc_andm(spc, dst, src);
break;
}
case 0x39: { // andm ind, ind
uint16_t src = 0;
uint16_t dst = spc_adrIndInd(spc, &src);
spc_andm(spc, dst, src);
break;
}
case 0x3a: { // incw dp
uint16_t low = 0;
uint16_t high = spc_adrDpWord(spc, &low);
uint16_t value = spc_readWord(spc, low, high) + 1;
spc->z = value == 0;
spc->n = value & 0x8000;
spc_writeWord(spc, low, high, value);
break;
}
case 0x3b: { // rol dpx
spc_rol(spc, spc_adrDpx(spc));
break;
}
case 0x3c: { // rola imp
bool newC = spc->a & 0x80;
spc->a = (spc->a << 1) | (uint8_t)spc->c;
spc->c = newC;
spc_setZN(spc, spc->a);
break;
}
case 0x3d: { // incx imp
spc->x++;
spc_setZN(spc, spc->x);
break;
}
case 0x3e: { // cmpx dp
spc_cmpx(spc, spc_adrDp(spc));
break;
}
case 0x3f: { // call abs
uint16_t dst = spc_readOpcodeWord(spc);
spc_pushWord(spc, spc->pc);
spc->pc = dst;
break;
}
case 0x40: { // setp imp
spc->p = true;
break;
}
case 0x44: { // eor dp
spc_eor(spc, spc_adrDp(spc));
break;
}
case 0x45: { // eor abs
spc_eor(spc, spc_adrAbs(spc));
break;
}
case 0x46: { // eor ind
spc_eor(spc, spc_adrInd(spc));
break;
}
case 0x47: { // eor idx
spc_eor(spc, spc_adrIdx(spc));
break;
}
case 0x48: { // eor imm
spc_eor(spc, spc_adrImm(spc));
break;
}
case 0x49: { // eorm dp, dp
uint16_t src = 0;
uint16_t dst = spc_adrDpDp(spc, &src);
spc_eorm(spc, dst, src);
break;
}
case 0x4a: { // and1 abs.bit
uint16_t adr = 0;
uint8_t bit = spc_adrAbsBit(spc, &adr);
spc->c = spc->c & ((spc_read(spc, adr) >> bit) & 1);
break;
}
case 0x4b: { // lsr dp
spc_lsr(spc, spc_adrDp(spc));
break;
}
case 0x4c: { // lsr abs
spc_lsr(spc, spc_adrAbs(spc));
break;
}
case 0x4d: { // pushx imp
spc_pushByte(spc, spc->x);
break;
}
case 0x4e: { // tclr1 abs
uint16_t adr = spc_adrAbs(spc);
uint8_t val = spc_read(spc, adr);
uint8_t result = spc->a + (val ^ 0xff) + 1;
spc_setZN(spc, result);
spc_write(spc, adr, val & ~spc->a);
break;
}
case 0x4f: { // pcall dp
uint8_t dst = spc_readOpcode(spc);
spc_pushWord(spc, spc->pc);
spc->pc = 0xff00 | dst;
break;
}
case 0x50: { // bvc rel
spc_doBranch(spc, spc_readOpcode(spc), !spc->v);
break;
}
case 0x54: { // eor dpx
spc_eor(spc, spc_adrDpx(spc));
break;
}
case 0x55: { // eor abx
spc_eor(spc, spc_adrAbx(spc));
break;
}
case 0x56: { // eor aby
spc_eor(spc, spc_adrAby(spc));
break;
}
case 0x57: { // eor idy
spc_eor(spc, spc_adrIdy(spc));
break;
}
case 0x58: { // eorm dp, imm
uint16_t src = 0;
uint16_t dst = spc_adrDpImm(spc, &src);
spc_eorm(spc, dst, src);
break;
}
case 0x59: { // eorm ind, ind
uint16_t src = 0;
uint16_t dst = spc_adrIndInd(spc, &src);
spc_eorm(spc, dst, src);
break;
}
case 0x5a: { // cmpw dp
uint16_t low = 0;
uint16_t high = spc_adrDpWord(spc, &low);
uint16_t value = spc_readWord(spc, low, high) ^ 0xffff;
uint16_t ya = spc->a | (spc->y << 8);
int result = ya + value + 1;
spc->c = result > 0xffff;
spc->z = (result & 0xffff) == 0;
spc->n = result & 0x8000;
break;
}
case 0x5b: { // lsr dpx
spc_lsr(spc, spc_adrDpx(spc));
break;
}
case 0x5c: { // lsra imp
spc->c = spc->a & 1;
spc->a >>= 1;
spc_setZN(spc, spc->a);
break;
}
case 0x5d: { // movxa imp
spc->x = spc->a;
spc_setZN(spc, spc->x);
break;
}
case 0x5e: { // cmpy abs
spc_cmpy(spc, spc_adrAbs(spc));
break;
}
case 0x5f: { // jmp abs
spc->pc = spc_readOpcodeWord(spc);
break;
}
case 0x60: { // clrc imp
spc->c = false;
break;
}
case 0x64: { // cmp dp
spc_cmp(spc, spc_adrDp(spc));
break;
}
case 0x65: { // cmp abs
spc_cmp(spc, spc_adrAbs(spc));
break;
}
case 0x66: { // cmp ind
spc_cmp(spc, spc_adrInd(spc));
break;
}
case 0x67: { // cmp idx
spc_cmp(spc, spc_adrIdx(spc));
break;
}
case 0x68: { // cmp imm
spc_cmp(spc, spc_adrImm(spc));
break;
}
case 0x69: { // cmpm dp, dp
uint16_t src = 0;
uint16_t dst = spc_adrDpDp(spc, &src);
spc_cmpm(spc, dst, src);
break;
}
case 0x6a: { // and1n abs.bit
uint16_t adr = 0;
uint8_t bit = spc_adrAbsBit(spc, &adr);
spc->c = spc->c & (~(spc_read(spc, adr) >> bit) & 1);
break;
}
case 0x6b: { // ror dp
spc_ror(spc, spc_adrDp(spc));
break;
}
case 0x6c: { // ror abs
spc_ror(spc, spc_adrAbs(spc));
break;
}
case 0x6d: { // pushy imp
spc_pushByte(spc, spc->y);
break;
}
case 0x6e: { // dbnz dp, rel
uint16_t adr = spc_adrDp(spc);
uint8_t result = spc_read(spc, adr) - 1;
spc_write(spc, adr, result);
spc_doBranch(spc, spc_readOpcode(spc), result != 0);
break;
}
case 0x6f: { // ret imp
spc->pc = spc_pullWord(spc);
break;
}
case 0x70: { // bvs rel
spc_doBranch(spc, spc_readOpcode(spc), spc->v);
break;
}
case 0x74: { // cmp dpx
spc_cmp(spc, spc_adrDpx(spc));
break;
}
case 0x75: { // cmp abx
spc_cmp(spc, spc_adrAbx(spc));
break;
}
case 0x76: { // cmp aby
spc_cmp(spc, spc_adrAby(spc));
break;
}
case 0x77: { // cmp idy
spc_cmp(spc, spc_adrIdy(spc));
break;
}
case 0x78: { // cmpm dp, imm
uint16_t src = 0;
uint16_t dst = spc_adrDpImm(spc, &src);
spc_cmpm(spc, dst, src);
break;
}
case 0x79: { // cmpm ind, ind
uint16_t src = 0;
uint16_t dst = spc_adrIndInd(spc, &src);
spc_cmpm(spc, dst, src);
break;
}
case 0x7a: { // addw dp
uint16_t low = 0;
uint16_t high = spc_adrDpWord(spc, &low);
uint16_t value = spc_readWord(spc, low, high);
uint16_t ya = spc->a | (spc->y << 8);
int result = ya + value;
spc->v = (ya & 0x8000) == (value & 0x8000) && (value & 0x8000) != (result & 0x8000);
spc->h = ((ya & 0xfff) + (value & 0xfff) + 1) > 0xfff;
spc->c = result > 0xffff;
spc->z = (result & 0xffff) == 0;
spc->n = result & 0x8000;
spc->a = result & 0xff;
spc->y = result >> 8;
break;
}
case 0x7b: { // ror dpx
spc_ror(spc, spc_adrDpx(spc));
break;
}
case 0x7c: { // rora imp
bool newC = spc->a & 1;
spc->a = (spc->a >> 1) | (spc->c << 7);
spc->c = newC;
spc_setZN(spc, spc->a);
break;
}
case 0x7d: { // movax imp
spc->a = spc->x;
spc_setZN(spc, spc->a);
break;
}
case 0x7e: { // cmpy dp
spc_cmpy(spc, spc_adrDp(spc));
break;
}
case 0x7f: { // reti imp
spc_setFlags(spc, spc_pullByte(spc));
spc->pc = spc_pullWord(spc);
break;
}
case 0x80: { // setc imp
spc->c = true;
break;
}
case 0x84: { // adc dp
spc_adc(spc, spc_adrDp(spc));
break;
}
case 0x85: { // adc abs
spc_adc(spc, spc_adrAbs(spc));
break;
}
case 0x86: { // adc ind
spc_adc(spc, spc_adrInd(spc));
break;
}
case 0x87: { // adc idx
spc_adc(spc, spc_adrIdx(spc));
break;
}
case 0x88: { // adc imm
spc_adc(spc, spc_adrImm(spc));
break;
}
case 0x89: { // adcm dp, dp
uint16_t src = 0;
uint16_t dst = spc_adrDpDp(spc, &src);
spc_adcm(spc, dst, src);
break;
}
case 0x8a: { // eor1 abs.bit
uint16_t adr = 0;
uint8_t bit = spc_adrAbsBit(spc, &adr);
spc->c = spc->c ^ ((spc_read(spc, adr) >> bit) & 1);
break;
}
case 0x8b: { // dec dp
spc_dec(spc, spc_adrDp(spc));
break;
}
case 0x8c: { // dec abs
spc_dec(spc, spc_adrAbs(spc));
break;
}
case 0x8d: { // movy imm
spc_movy(spc, spc_adrImm(spc));
break;
}
case 0x8e: { // popp imp
spc_setFlags(spc, spc_pullByte(spc));
break;
}
case 0x8f: { // movm dp, imm
uint16_t src = 0;
uint16_t dst = spc_adrDpImm(spc, &src);
uint8_t val = spc_read(spc, src);
spc_read(spc, dst);
spc_write(spc, dst, val);
break;
}
case 0x90: { // bcc rel
spc_doBranch(spc, spc_readOpcode(spc), !spc->c);
break;
}
case 0x94: { // adc dpx
spc_adc(spc, spc_adrDpx(spc));
break;
}
case 0x95: { // adc abx
spc_adc(spc, spc_adrAbx(spc));
break;
}
case 0x96: { // adc aby
spc_adc(spc, spc_adrAby(spc));
break;
}
case 0x97: { // adc idy
spc_adc(spc, spc_adrIdy(spc));
break;
}
case 0x98: { // adcm dp, imm
uint16_t src = 0;
uint16_t dst = spc_adrDpImm(spc, &src);
spc_adcm(spc, dst, src);
break;
}
case 0x99: { // adcm ind, ind
uint16_t src = 0;
uint16_t dst = spc_adrIndInd(spc, &src);
spc_adcm(spc, dst, src);
break;
}
case 0x9a: { // subw dp
uint16_t low = 0;
uint16_t high = spc_adrDpWord(spc, &low);
uint16_t value = spc_readWord(spc, low, high) ^ 0xffff;
uint16_t ya = spc->a | (spc->y << 8);
int result = ya + value + 1;
spc->v = (ya & 0x8000) == (value & 0x8000) && (value & 0x8000) != (result & 0x8000);
spc->h = ((ya & 0xfff) + (value & 0xfff) + 1) > 0xfff;
spc->c = result > 0xffff;
spc->z = (result & 0xffff) == 0;
spc->n = result & 0x8000;
spc->a = result & 0xff;
spc->y = result >> 8;
break;
}
case 0x9b: { // dec dpx
spc_dec(spc, spc_adrDpx(spc));
break;
}
case 0x9c: { // deca imp
spc->a--;
spc_setZN(spc, spc->a);
break;
}
case 0x9d: { // movxp imp
spc->x = spc->sp;
spc_setZN(spc, spc->x);
break;
}
case 0x9e: { // div imp
// TODO: proper division algorithm
uint16_t value = spc->a | (spc->y << 8);
int result = 0xffff;
int mod = spc->a;
if(spc->x != 0) {
result = value / spc->x;
mod = value % spc->x;
}
spc->v = result > 0xff;
spc->h = (spc->x & 0xf) <= (spc->y & 0xf);
spc->a = result;
spc->y = mod;
spc_setZN(spc, spc->a);
break;
}
case 0x9f: { // xcn imp
spc->a = (spc->a >> 4) | (spc->a << 4);
spc_setZN(spc, spc->a);
break;
}
case 0xa0: { // ei imp
spc->i = true;
break;
}
case 0xa4: { // sbc dp
spc_sbc(spc, spc_adrDp(spc));
break;
}
case 0xa5: { // sbc abs
spc_sbc(spc, spc_adrAbs(spc));
break;
}
case 0xa6: { // sbc ind
spc_sbc(spc, spc_adrInd(spc));
break;
}
case 0xa7: { // sbc idx
spc_sbc(spc, spc_adrIdx(spc));
break;
}
case 0xa8: { // sbc imm
spc_sbc(spc, spc_adrImm(spc));
break;
}
case 0xa9: { // sbcm dp, dp
uint16_t src = 0;
uint16_t dst = spc_adrDpDp(spc, &src);
spc_sbcm(spc, dst, src);
break;
}
case 0xaa: { // mov1 abs.bit
uint16_t adr = 0;
uint8_t bit = spc_adrAbsBit(spc, &adr);
spc->c = (spc_read(spc, adr) >> bit) & 1;
break;
}
case 0xab: { // inc dp
spc_inc(spc, spc_adrDp(spc));
break;
}
case 0xac: { // inc abs
spc_inc(spc, spc_adrAbs(spc));
break;
}
case 0xad: { // cmpy imm
spc_cmpy(spc, spc_adrImm(spc));
break;
}
case 0xae: { // popa imp
spc->a = spc_pullByte(spc);
break;
}
case 0xaf: { // movs ind+
uint16_t adr = spc_adrIndP(spc);
spc_write(spc, adr, spc->a);
break;
}
case 0xb0: { // bcs rel
spc_doBranch(spc, spc_readOpcode(spc), spc->c);
break;
}
case 0xb4: { // sbc dpx
spc_sbc(spc, spc_adrDpx(spc));
break;
}
case 0xb5: { // sbc abx
spc_sbc(spc, spc_adrAbx(spc));
break;
}
case 0xb6: { // sbc aby
spc_sbc(spc, spc_adrAby(spc));
break;
}
case 0xb7: { // sbc idy
spc_sbc(spc, spc_adrIdy(spc));
break;
}
case 0xb8: { // sbcm dp, imm
uint16_t src = 0;
uint16_t dst = spc_adrDpImm(spc, &src);
spc_sbcm(spc, dst, src);
break;
}
case 0xb9: { // sbcm ind, ind
uint16_t src = 0;
uint16_t dst = spc_adrIndInd(spc, &src);
spc_sbcm(spc, dst, src);
break;
}
case 0xba: { // movw dp
uint16_t low = 0;
uint16_t high = spc_adrDpWord(spc, &low);
uint16_t val = spc_readWord(spc, low, high);
spc->a = val & 0xff;
spc->y = val >> 8;
spc->z = val == 0;
spc->n = val & 0x8000;
break;
}
case 0xbb: { // inc dpx
spc_inc(spc, spc_adrDpx(spc));
break;
}
case 0xbc: { // inca imp
spc->a++;
spc_setZN(spc, spc->a);
break;
}
case 0xbd: { // movpx imp
spc->sp = spc->x;
break;
}
case 0xbe: { // das imp
if(spc->a > 0x99 || !spc->c) {
spc->a -= 0x60;
spc->c = false;
}
if((spc->a & 0xf) > 9 || !spc->h) {
spc->a -= 6;
}
spc_setZN(spc, spc->a);
break;
}
case 0xbf: { // mov ind+
uint16_t adr = spc_adrIndP(spc);
spc->a = spc_read(spc, adr);
spc_setZN(spc, spc->a);
break;
}
case 0xc0: { // di imp
spc->i = false;
break;
}
case 0xc4: { // movs dp
spc_movs(spc, spc_adrDp(spc));
break;
}
case 0xc5: { // movs abs
spc_movs(spc, spc_adrAbs(spc));
break;
}
case 0xc6: { // movs ind
spc_movs(spc, spc_adrInd(spc));
break;
}
case 0xc7: { // movs idx
spc_movs(spc, spc_adrIdx(spc));
break;
}
case 0xc8: { // cmpx imm
spc_cmpx(spc, spc_adrImm(spc));
break;
}
case 0xc9: { // movsx abs
spc_movsx(spc, spc_adrAbs(spc));
break;
}
case 0xca: { // mov1s abs.bit
uint16_t adr = 0;
uint8_t bit = spc_adrAbsBit(spc, &adr);
uint8_t result = (spc_read(spc, adr) & (~(1 << bit))) | (spc->c << bit);
spc_write(spc, adr, result);
break;
}
case 0xcb: { // movsy dp
spc_movsy(spc, spc_adrDp(spc));
break;
}
case 0xcc: { // movsy abs
spc_movsy(spc, spc_adrAbs(spc));
break;
}
case 0xcd: { // movx imm
spc_movx(spc, spc_adrImm(spc));
break;
}
case 0xce: { // popx imp
spc->x = spc_pullByte(spc);
break;
}
case 0xcf: { // mul imp
uint16_t result = spc->a * spc->y;
spc->a = result & 0xff;
spc->y = result >> 8;
spc_setZN(spc, spc->y);
break;
}
case 0xd0: { // bne rel
spc_doBranch(spc, spc_readOpcode(spc), !spc->z);
break;
}
case 0xd4: { // movs dpx
spc_movs(spc, spc_adrDpx(spc));
break;
}
case 0xd5: { // movs abx
spc_movs(spc, spc_adrAbx(spc));
break;
}
case 0xd6: { // movs aby
spc_movs(spc, spc_adrAby(spc));
break;
}
case 0xd7: { // movs idy
spc_movs(spc, spc_adrIdy(spc));
break;
}
case 0xd8: { // movsx dp
spc_movsx(spc, spc_adrDp(spc));
break;
}
case 0xd9: { // movsx dpy
spc_movsx(spc, spc_adrDpy(spc));
break;
}
case 0xda: { // movws dp
uint16_t low = 0;
uint16_t high = spc_adrDpWord(spc, &low);
spc_read(spc, low);
spc_write(spc, low, spc->a);
spc_write(spc, high, spc->y);
break;
}
case 0xdb: { // movsy dpx
spc_movsy(spc, spc_adrDpx(spc));
break;
}
case 0xdc: { // decy imp
spc->y--;
spc_setZN(spc, spc->y);
break;
}
case 0xdd: { // movay imp
spc->a = spc->y;
spc_setZN(spc, spc->a);
break;
}
case 0xde: { // cbne dpx, rel
uint8_t val = spc_read(spc, spc_adrDpx(spc)) ^ 0xff;
uint8_t result = spc->a + val + 1;
spc_doBranch(spc, spc_readOpcode(spc), result != 0);
break;
}
case 0xdf: { // daa imp
if(spc->a > 0x99 || spc->c) {
spc->a += 0x60;
spc->c = true;
}
if((spc->a & 0xf) > 9 || spc->h) {
spc->a += 6;
}
spc_setZN(spc, spc->a);
break;
}
case 0xe0: { // clrv imp
spc->v = false;
spc->h = false;
break;
}
case 0xe4: { // mov dp
spc_mov(spc, spc_adrDp(spc));
break;
}
case 0xe5: { // mov abs
spc_mov(spc, spc_adrAbs(spc));
break;
}
case 0xe6: { // mov ind
spc_mov(spc, spc_adrInd(spc));
break;
}
case 0xe7: { // mov idx
spc_mov(spc, spc_adrIdx(spc));
break;
}
case 0xe8: { // mov imm
spc_mov(spc, spc_adrImm(spc));
break;
}
case 0xe9: { // movx abs
spc_movx(spc, spc_adrAbs(spc));
break;
}
case 0xea: { // not1 abs.bit
uint16_t adr = 0;
uint8_t bit = spc_adrAbsBit(spc, &adr);
uint8_t result = spc_read(spc, adr) ^ (1 << bit);
spc_write(spc, adr, result);
break;
}
case 0xeb: { // movy dp
spc_movy(spc, spc_adrDp(spc));
break;
}
case 0xec: { // movy abs
spc_movy(spc, spc_adrAbs(spc));
break;
}
case 0xed: { // notc imp
spc->c = !spc->c;
break;
}
case 0xee: { // popy imp
spc->y = spc_pullByte(spc);
break;
}
case 0xef: { // sleep imp
spc->stopped = true; // no interrupts, so sleeping stops as well
break;
}
case 0xf0: { // beq rel
spc_doBranch(spc, spc_readOpcode(spc), spc->z);
break;
}
case 0xf4: { // mov dpx
spc_mov(spc, spc_adrDpx(spc));
break;
}
case 0xf5: { // mov abx
spc_mov(spc, spc_adrAbx(spc));
break;
}
case 0xf6: { // mov aby
spc_mov(spc, spc_adrAby(spc));
break;
}
case 0xf7: { // mov idy
spc_mov(spc, spc_adrIdy(spc));
break;
}
case 0xf8: { // movx dp
spc_movx(spc, spc_adrDp(spc));
break;
}
case 0xf9: { // movx dpy
spc_movx(spc, spc_adrDpy(spc));
break;
}
case 0xfa: { // movm dp, dp
uint16_t src = 0;
uint16_t dst = spc_adrDpDp(spc, &src);
uint8_t val = spc_read(spc, src);
spc_write(spc, dst, val);
break;
}
case 0xfb: { // movy dpx
spc_movy(spc, spc_adrDpx(spc));
break;
}
case 0xfc: { // incy imp
spc->y++;
spc_setZN(spc, spc->y);
break;
}
case 0xfd: { // movya imp
spc->y = spc->a;
spc_setZN(spc, spc->y);
break;
}
case 0xfe: { // dbnzy rel
spc->y--;
spc_doBranch(spc, spc_readOpcode(spc), spc->y != 0);
break;
}
case 0xff: { // stop imp
spc->stopped = true;
break;
}
}
}