- Més de la meitat de opcodes implementats

This commit is contained in:
2025-02-01 11:19:52 +01:00
parent 033acb7124
commit 2c62a32264

567
6502.cpp
View File

@@ -34,7 +34,7 @@ namespace cpu6502
#define aZeroPage 2
#define aZeroPageX 3
#define aZeroPageY 4
#define aRelative 5
#define aRelative 5 // Is really needed?
#define aIndirect 6
#define aIndirectX 7
#define aIndirectY 8
@@ -42,6 +42,11 @@ namespace cpu6502
#define aAbsoluteX 10
#define aAbsoluteY 11
#define FLAG_IS_RESET true
#define FLAG_IS_SET false
uint8_t i_reg_value = 0;
uint8_t regs[7];
uint8_t *_rA = &regs[0];
@@ -63,7 +68,7 @@ namespace cpu6502
uint8_t READ_MEM_8(const uint16_t addr, const bool code=false)
{
if (debug::isbreak(addr, 2)) debug::stop();
t+=1; //[TODO]
//t+=1; //[TODO]
const uint8_t tag = mem::getTag(addr);
if ( !(tag&MEMTAG_IGNORE) ) {
@@ -110,7 +115,7 @@ namespace cpu6502
const uint8_t WRITE_MEM_8(const uint16_t addr, const uint8_t value)
{
t+=1; // [TODO]
//t+=1; // [TODO]
mem::writeMem(addr, value);
if (debug::isbreak(addr, 4)) debug::stop();
@@ -148,24 +153,302 @@ namespace cpu6502
}
void notImplemented()
{
}
uint16_t addr_mode_address = 0;
bool page_crossed = false;
uint8_t loadValue(uint8_t addr_mode)
{
page_crossed = false;
switch (addr_mode)
{
case aAccumulator:
t+=2;
return rA;
case aImmediate:
t+=2;
return READ_MEM_8();
case aZeroPage:
t+=3;
addr_mode_address = READ_MEM_8();
return READ_MEM_8(addr_mode_address);
case aZeroPageX:
t+=4;
addr_mode_address = (READ_MEM_8()+rX)&0xff;
return READ_MEM_8(addr_mode_address);
case aZeroPageY:
t+=4;
addr_mode_address = (READ_MEM_8()+rY)&0xff;
return READ_MEM_8(addr_mode_address);
case aIndirectX:
t+=6;
addr_mode_address = READ_MEM_16((READ_MEM_8()+rX)&0xff);
return READ_MEM_8(addr_mode_address);
case aIndirectY:
t+=5;
addr_mode_address = READ_MEM_16(READ_MEM_8());
if ( (addr_mode_address&0xff) + rY > 0xff ) { t++; page_crossed=true; }
addr_mode_address = (addr_mode_address+rY)&0xffff;
return READ_MEM_8(addr_mode_address);
case aAbsolute:
t+=4;
addr_mode_address = READ_MEM_16();
return READ_MEM_8(addr_mode_address);
case aAbsoluteX:
t+=4;
addr_mode_address = READ_MEM_16();
if ( (addr_mode_address&0xff) + rX > 0xff ) { t++; page_crossed=true; }
addr_mode_address = (addr_mode_address+rX) & 0xffff;
return READ_MEM_8(addr_mode_address);
case aAbsoluteY:
t+=4;
addr_mode_address = READ_MEM_16();
if ( (addr_mode_address&0xff) + rY > 0xff ) { t++; page_crossed=true; }
addr_mode_address = (addr_mode_address+rY) & 0xffff;
return READ_MEM_8(addr_mode_address);
}
}
void storeValue(uint8_t value, uint8_t addr_mode)
{
switch (addr_mode)
{
case aAccumulator:
rA = value;
break;
case aZeroPage:
case aZeroPageX:
case aZeroPageY:
t+=2;
WRITE_MEM_8(addr_mode_address, value);
break;
case aIndirectX:
WRITE_MEM_8(addr_mode_address, value);
break;
case aAbsolute:
t+=2;
WRITE_MEM_8(addr_mode_address, value);
break;
case aAbsoluteX:
t+=page_crossed?2:3;
WRITE_MEM_8(addr_mode_address, value);
break;
}
}
void PHP()
{
t+= 3;
WRITE_MEM_8(0x0100+rS, rP|f1|fB); rS--;
}
void PHA()
{
t+= 3;
WRITE_MEM_8(0x0100+rS, rA); rS--;
}
void PLP()
{
t+=4;
rS++;
rP = READ_MEM_8(0x0100+rS) & ~(f1|fB);
}
void PLA()
{
t+=4;
rS++;
rA = READ_MEM_8(0x0100+rS);
rP = ( rP & ~fN ) | ( rA & fN );
rP = ( rA ? rP & ~fZ : rP | fZ );
}
void BRK()
{
rPC++;
READ_MEM_8();
WRITE_MEM_16(0x0100+rS, rPC); rS-=2;
WRITE_MEM_8(0x0100+rS, rP|f1|fB); rS--;
PHP(); // t+=3
rP |= fI;
rPC = READ_MEM_16(0xfffe);
t++;
t+=4;
}
void RTI()
{
PLP(); i_reg_value = rP&fI; // effect of changing fI is not delayed
rS+=2;
rPC = READ_MEM_16(0x0100+rS);
t+=2;
}
void ADC(uint8_t addr_mode)
{
uint8_t value = loadValue(addr_mode);
uint16_t result = rA + value + fC;
rA = result & 0xff;
rP = ( rP & ~fC ) | ( (result>>8) & fC );
rP = ( rP & ~fN ) | ( rA & fN );
rP = ( rA ? rP & ~fZ : rP | fZ );
rP = ( (result ^ rA) & (result ^ value) & 0x80 ) ? rP | fV : rP & ~fV;
}
void ORA(uint8_t addr_mode)
{
uint8_t value = loadValue(addr_mode);
rA |= value;
rP = ( rP & ~fN ) | ( rA & fN );
rP = ( rA ? rP & ~fZ : rP | fZ );
}
void AND(uint8_t addr_mode)
{
uint8_t value = loadValue(addr_mode);
rA &= value;
rP = ( rP & ~fN ) | ( rA & fN );
rP = ( rA ? rP & ~fZ : rP | fZ );
}
void EOR(uint8_t addr_mode)
{
uint8_t value = loadValue(addr_mode);
rA = rA ^ value;
rP = ( rP & ~fN ) | ( rA & fN );
rP = ( rA ? rP & ~fZ : rP | fZ );
}
void BIT(uint8_t addr_mode)
{
uint8_t value = loadValue(addr_mode);
uint8_t result = rA & value;
rP = ( rP & ~(fN|fV) ) | ( rA & (fN|fV) );
rP = ( rA ? rP & ~fZ : rP | fZ );
}
void ASL(uint8_t addr_mode)
{
uint8_t value = loadValue(addr_mode);
rP = ( rP & ~fC ) | ( (value & 0x80)>>7 );
value = value << 1;
rP = ( rP & ~fN ) | ( value & fN );
rP = ( value ? rP & ~fZ : rP | fZ );
storeValue(value, addr_mode);
}
void LSR(uint8_t addr_mode)
{
uint8_t value = loadValue(addr_mode);
rP = ( rP & ~fC ) | ( (value & fC) );
value = value >> 1;
rP = ( rP & ~fN ) | ( value & fN );
rP = ( value ? rP & ~fZ : rP | fZ );
storeValue(value, addr_mode);
}
void ROL(uint8_t addr_mode)
{
uint8_t value = loadValue(addr_mode);
uint8_t old_fC = rP & fC;
rP = ( rP & ~fC ) | ( (value & 0x80)>>7 );
value = (value << 1) | old_fC;
rP = ( rP & ~fN ) | ( value & fN );
rP = ( value ? rP & ~fZ : rP | fZ );
storeValue(value, addr_mode);
}
void ROR(uint8_t addr_mode)
{
uint8_t value = loadValue(addr_mode);
uint8_t old_fC = (rP & fC) << 7;
rP = ( rP & ~fC ) | ( (value & fC) );
value = (value >> 1) | old_fC;
rP = ( rP & ~fN ) | ( value & fN );
rP = ( value ? rP & ~fZ : rP | fZ );
storeValue(value, addr_mode);
}
void JMP(uint8_t addr_mode)
{
t+=3;
addr_mode_address = READ_MEM_16();
if (addr_mode == aIndirect) {
t+=5;
const uint8_t L = READ_MEM_8(addr_mode_address);
const uint8_t H = READ_MEM_8( (addr_mode_address&0xff00) | ((addr_mode_address+1)&0x00ff) );
addr_mode_address = (H << 8) + L;
}
rPC = addr_mode_address;
}
void BRANCH(uint8_t flag, bool negate)
{
t+=3;
int8_t offset = (int8_t)READ_MEM_8();
bool condition = (rP & flag);
if (negate) condition = !condition;
if (condition) {
t++;
if ( (rPC&0xff) + offset > 0xff ) t++;
rPC = (rPC + offset) & 0xffff;
}
}
void BPL() { BRANCH(fN, FLAG_IS_RESET); }
void BMI() { BRANCH(fN, FLAG_IS_SET); }
void BNE() { BRANCH(fZ, FLAG_IS_RESET); }
void BEQ() { BRANCH(fZ, FLAG_IS_SET); }
void BCC() { BRANCH(fC, FLAG_IS_RESET); }
void BCS() { BRANCH(fC, FLAG_IS_SET); }
void BVC() { BRANCH(fV, FLAG_IS_RESET); }
void BVS() { BRANCH(fV, FLAG_IS_SET); }
void JSR(uint8_t addr_mode)
{
uint8_t value = loadValue(addr_mode);
t+=2;
WRITE_MEM_16(0x0100+rS, rPC-1); rS-=2;
rPC = value;
}
void RTS()
{
rS+=2;
rPC = READ_MEM_16(0x0100+rS);
rPC++;
t+=6;
}
void SET_FLAG(uint8_t flag) { t+=2; rP = rP | flag; }
void SEC() { SET_FLAG(fC); }
void SED() { SET_FLAG(fD); }
void SEI() { SET_FLAG(fI); }
void CLEAR_FLAG(uint8_t flag) { t+=2; rP = rP & ~flag; }
void CLC() { CLEAR_FLAG(fC); }
void CLD() { CLEAR_FLAG(fD); }
void CLI() { CLEAR_FLAG(fI); }
void CLV() { CLEAR_FLAG(fV); }
uint32_t step()
{
t = 0;
i_reg_value = rP & fI;
uint16_t current_opcode_address = rPC;
const uint8_t opcode = READ_M1();
@@ -179,9 +462,279 @@ namespace cpu6502
{
case 0x00: BRK(); break;
case 0x01: ORA(aIndirectX); break;
case 0x02: notImplemented(); break;
case 0x03: notImplemented(); break;
case 0x04: notImplemented(); break;
case 0x05: ORA(aZeroPage); break;
case 0x06: ASL(aZeroPage); break;
case 0x07: notImplemented(); break;
case 0x08: PHP(); break;
case 0x09: ORA(aImmediate); break;
case 0x0a: ASL(aAccumulator); break;
case 0x0b: notImplemented(); break;
case 0x0c: notImplemented(); break;
case 0x0d: ORA(aAbsolute); break;
case 0x0e: ASL(aAbsolute); break;
case 0x0f: notImplemented(); break;
case 0x10: BPL(); break;
case 0x11: ORA(aIndirectY); break;
case 0x12: notImplemented(); break;
case 0x13: notImplemented(); break;
case 0x14: notImplemented(); break;
case 0x15: ORA(aZeroPageX); break;
case 0x16: ASL(aZeroPageX); break;
case 0x17: notImplemented(); break;
case 0x18: CLC(); break;
case 0x19: ORA(aAbsoluteY); break;
case 0x1a: notImplemented(); break;
case 0x1b: notImplemented(); break;
case 0x1c: notImplemented(); break;
case 0x1d: ORA(aAbsoluteX); break;
case 0x1e: ASL(aAbsoluteX); break;
case 0x1f: notImplemented(); break;
case 0x20: JSR(aAbsolute); break;
case 0x21: AND(aIndirectX); break;
case 0x22: notImplemented(); break;
case 0x23: notImplemented(); break;
case 0x24: BIT(aZeroPage); break;
case 0x25: AND(aZeroPage); break;
case 0x26: ROL(aZeroPage); break;
case 0x27: notImplemented(); break;
case 0x28: PLP(); break;
case 0x29: AND(aImmediate); break;
case 0x2a: ROL(aAccumulator); break;
case 0x2b: notImplemented(); break;
case 0x2c: BIT(aAbsolute); break;
case 0x2d: AND(aAbsolute); break;
case 0x2e: ROL(aAbsolute); break;
case 0x2f: notImplemented(); break;
case 0x30: BMI(); break;
case 0x31: AND(aIndirectY); break;
case 0x32: notImplemented(); break;
case 0x33: notImplemented(); break;
case 0x34: notImplemented(); break;
case 0x35: AND(aZeroPageX); break;
case 0x36: ROL(aZeroPageX); break;
case 0x37: notImplemented(); break;
case 0x38: SEC(); break;
case 0x39: AND(aAbsoluteY); break;
case 0x3a: notImplemented(); break;
case 0x3b: notImplemented(); break;
case 0x3c: notImplemented(); break;
case 0x3d: AND(aAbsoluteX); break;
case 0x3e: ROL(aAbsoluteX); break;
case 0x3f: notImplemented(); break;
case 0x40: RTI(); break;
case 0x41: EOR(aIndirectX); break;
case 0x42: notImplemented(); break;
case 0x43: notImplemented(); break;
case 0x44: notImplemented(); break;
case 0x45: EOR(aZeroPage); break;
case 0x46: LSR(aZeroPage); break;
case 0x47: notImplemented(); break;
case 0x48: PHA(); break;
case 0x49: EOR(aImmediate); break;
case 0x4a: LSR(aAccumulator); break;
case 0x4b: notImplemented(); break;
case 0x4c: JMP(aAbsolute); break;
case 0x4d: EOR(aAbsolute); break;
case 0x4e: LSR(aAbsolute); break;
case 0x4f: notImplemented(); break;
case 0x50: BVC(); break;
case 0x51: EOR(aIndirectY); break;
case 0x52: notImplemented(); break;
case 0x53: notImplemented(); break;
case 0x54: notImplemented(); break;
case 0x55: EOR(aZeroPageX); break;
case 0x56: LSR(aZeroPageX); break;
case 0x57: notImplemented(); break;
case 0x58: CLI(); break;
case 0x59: EOR(aAbsoluteY); break;
case 0x5a: notImplemented(); break;
case 0x5b: notImplemented(); break;
case 0x5c: notImplemented(); break;
case 0x5d: EOR(aAbsoluteX); break;
case 0x5e: LSR(aAbsoluteX); break;
case 0x5f: notImplemented(); break;
case 0x60: RTS(); break;
case 0x61: ADC(aIndirectX); break;
case 0x62: notImplemented(); break;
case 0x63: notImplemented(); break;
case 0x64: notImplemented(); break;
case 0x65: ADC(aZeroPage); break;
case 0x66: ROR(aZeroPage); break;
case 0x67: notImplemented(); break;
case 0x68: PLA(); break;
case 0x69: ADC(aImmediate); break;
case 0x6a: ROR(aAccumulator); break;
case 0x6b: notImplemented(); break;
case 0x6c: JMP(aIndirect); break;
case 0x6d: ADC(aAbsolute); break;
case 0x6e: ROR(aAbsolute); break;
case 0x6f: notImplemented(); break;
case 0x70: BVS(); break;
case 0x71: ADC(aIndirectY); break;
case 0x72: notImplemented(); break;
case 0x73: notImplemented(); break;
case 0x74: notImplemented(); break;
case 0x75: ADC(aZeroPageX); break;
case 0x76: ROR(aZeroPageX); break;
case 0x77: notImplemented(); break;
case 0x78: SEI(); break;
case 0x79: ADC(aAbsoluteY); break;
case 0x7a: notImplemented(); break;
case 0x7b: notImplemented(); break;
case 0x7c: notImplemented(); break;
case 0x7d: ADC(aAbsoluteX); break;
case 0x7e: ROR(aAbsoluteX); break;
case 0x7f: notImplemented(); break;
case 0x80: notImplemented(); break;
case 0x81: break;
case 0x82: break;
case 0x83: notImplemented(); break;
case 0x84: notImplemented(); break;
case 0x85: break;
case 0x86: break;
case 0x87: notImplemented(); break;
case 0x88: break;
case 0x89: notImplemented(); break;
case 0x8a: break;
case 0x8b: notImplemented(); break;
case 0x8c: break;
case 0x8d: break;
case 0x8e: break;
case 0x8f: notImplemented(); break;
case 0x90: break;
case 0x91: break;
case 0x92: notImplemented(); break;
case 0x93: notImplemented(); break;
case 0x94: break;
case 0x95: break;
case 0x96: break;
case 0x97: notImplemented(); break;
case 0x98: break;
case 0x99: break;
case 0x9a: break;
case 0x9b: notImplemented(); break;
case 0x9c: notImplemented(); break;
case 0x9d: break;
case 0x9e: notImplemented(); break;
case 0x9f: notImplemented(); break;
case 0xa0: break;
case 0xa1: break;
case 0xa2: break;
case 0xa3: notImplemented(); break;
case 0xa4: break;
case 0xa5: break;
case 0xa6: break;
case 0xa7: notImplemented(); break;
case 0xa8: break;
case 0xa9: break;
case 0xaa: break;
case 0xab: notImplemented(); break;
case 0xac: break;
case 0xad: break;
case 0xae: break;
case 0xaf: notImplemented(); break;
case 0xb0: break;
case 0xb1: break;
case 0xb2: notImplemented(); break;
case 0xb3: notImplemented(); break;
case 0xb4: break;
case 0xb5: break;
case 0xb6: break;
case 0xb7: notImplemented(); break;
case 0xb8: break;
case 0xb9: break;
case 0xba: break;
case 0xbb: notImplemented(); break;
case 0xbc: break;
case 0xbd: break;
case 0xbe: break;
case 0xbf: notImplemented(); break;
case 0xc0: break;
case 0xc1: break;
case 0xc2: notImplemented(); break;
case 0xc3: notImplemented(); break;
case 0xc4: break;
case 0xc5: break;
case 0xc6: break;
case 0xc7: notImplemented(); break;
case 0xc8: break;
case 0xc9: break;
case 0xca: break;
case 0xcb: notImplemented(); break;
case 0xcc: break;
case 0xcd: break;
case 0xce: break;
case 0xcf: notImplemented(); break;
case 0xd0: break;
case 0xd1: break;
case 0xd2: notImplemented(); break;
case 0xd3: notImplemented(); break;
case 0xd4: notImplemented(); break;
case 0xd5: break;
case 0xd6: break;
case 0xd7: notImplemented(); break;
case 0xd8: break;
case 0xd9: break;
case 0xda: notImplemented(); break;
case 0xdb: notImplemented(); break;
case 0xdc: notImplemented(); break;
case 0xdd: break;
case 0xde: break;
case 0xdf: notImplemented(); break;
case 0xe0: break;
case 0xe1: break;
case 0xe2: notImplemented(); break;
case 0xe3: notImplemented(); break;
case 0xe4: break;
case 0xe5: break;
case 0xe6: break;
case 0xe7: notImplemented(); break;
case 0xe8: break;
case 0xe9: break;
case 0xea: break;
case 0xeb: notImplemented(); break;
case 0xec: break;
case 0xed: break;
case 0xee: break;
case 0xef: notImplemented(); break;
case 0xf0: break;
case 0xf1: break;
case 0xf2: notImplemented(); break;
case 0xf3: notImplemented(); break;
case 0xf4: notImplemented(); break;
case 0xf5: break;
case 0xf6: break;
case 0xf7: notImplemented(); break;
case 0xf8: break;
case 0xf9: break;
case 0xfa: notImplemented(); break;
case 0xfb: notImplemented(); break;
case 0xfc: notImplemented(); break;
case 0xfd: break;
case 0xfe: break;
case 0xff: notImplemented(); break;
};
// [TODO] Gestionar interrupcions
//if (!i_reg_value) gestionar interrupcions
//debug::setcursor(rPC);
//debug::history::store();