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aadded all instructions to run test rom

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This commit is contained in:
Lauchmelder 2021-10-23 18:52:09 +02:00
parent 2596ac2c65
commit 1af2c37b70
3 changed files with 106 additions and 4 deletions
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102
NES Emulator/cpu.c
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@ -388,6 +388,19 @@ void execute(struct CPU* cpu)
cpu->status.carry = (cpu->fetchedVal <= cpu->y);
} break;
case DCP:
{
cpu->fetchedVal--;
writeBus(cpu->bus, cpu->fetchedAddress, cpu->fetchedVal);
Byte result = cpu->acc - cpu->fetchedVal;
cpu->status.negative = (result >> 7);
cpu->status.zero = (result == 0x00);
cpu->status.carry = (cpu->fetchedVal <= cpu->acc);
cpu->remainingCycles = cpu->currentOpcode->cycles;
} break;
case DEC:
{
cpu->fetchedVal--;
@ -448,6 +461,22 @@ void execute(struct CPU* cpu)
cpu->status.zero = (cpu->y == 0x00);
} break;
case ISC:
{
cpu->fetchedVal++;
writeBus(cpu->bus, cpu->fetchedAddress, cpu->fetchedVal);
Word result = cpu->acc + ~cpu->fetchedVal + cpu->status.carry;
cpu->status.carry = ((result & 0x8000) != 0x8000);
cpu->status.overflow = ((~(cpu->acc ^ ~cpu->fetchedVal) & (cpu->acc ^ result) & 0x80) == 0x80);
cpu->status.negative = ((result & 0x80) == 0x80);
cpu->status.zero = ((result & 0xFF) == 0x00);
cpu->acc = result & 0xFF;
cpu->remainingCycles = cpu->currentOpcode->cycles;
} break;
case JMP:
{
cpu->pc.word = cpu->fetchedAddress;
@ -547,6 +576,23 @@ void execute(struct CPU* cpu)
cpu->status.raw = Pop(cpu->bus) | 0b00110000;
} break;
case RLA:
{
Byte oldCarry = cpu->status.carry;
cpu->status.carry = ((cpu->fetchedVal & 0x80) == 0x80);
cpu->fetchedVal <<= 1;
cpu->fetchedVal |= oldCarry;
writeBus(cpu->bus, cpu->fetchedAddress, cpu->fetchedVal);
cpu->acc &= cpu->fetchedVal;
cpu->status.negative = ((cpu->acc & 0x80) == 0x80);
cpu->status.zero = (cpu->acc == 0x00);
cpu->remainingCycles = cpu->currentOpcode->cycles;
} break;
case ROL:
{
Byte oldCarry = cpu->status.carry;
@ -581,6 +627,27 @@ void execute(struct CPU* cpu)
cpu->acc = cpu->fetchedVal;
} break;
case RRA:
{
Byte oldCarry = cpu->status.carry;
cpu->status.carry = ((cpu->fetchedVal & 0x01) == 0x01);
cpu->fetchedVal >>= 1;
cpu->fetchedVal |= (oldCarry << 7);
writeBus(cpu->bus, cpu->fetchedAddress, cpu->fetchedVal);
Word result = cpu->acc + cpu->fetchedVal + cpu->status.carry;
cpu->status.carry = (result > 0xFF);
cpu->status.overflow = ((~(cpu->acc ^ cpu->fetchedVal) & (cpu->acc ^ result) & 0x80) == 0x80);
cpu->status.negative = (result >> 7);
cpu->status.zero = ((result & 0xFF) == 0x00);
cpu->acc = result & 0xFF;
cpu->remainingCycles = cpu->currentOpcode->cycles;
} break;
case RTI:
{
cpu->status.raw = Pop(cpu->bus) | 0b00110000;
@ -596,6 +663,11 @@ void execute(struct CPU* cpu)
cpu->pc.word++;
} break;
case SAX:
{
writeBus(cpu->bus, cpu->fetchedAddress, cpu->acc & cpu->x);
} break;
case SBC:
{
Word result = cpu->acc + ~cpu->fetchedVal + cpu->status.carry;
@ -623,6 +695,36 @@ void execute(struct CPU* cpu)
cpu->status.id = 1;
} break;
case SLO:
{
cpu->status.carry = ((cpu->fetchedVal & 0x80) == 0x80);
cpu->fetchedVal <<= 1;
writeBus(cpu->bus, cpu->fetchedAddress, cpu->fetchedVal);
cpu->acc |= cpu->fetchedVal;
cpu->status.negative = ((cpu->acc & 0x80) == 0x80);
cpu->status.zero = (cpu->acc == 0x00);
cpu->remainingCycles = cpu->currentOpcode->cycles;
} break;
case SRE:
{
cpu->status.carry = ((cpu->fetchedVal & 0x01) == 0x01);
cpu->fetchedVal >>= 1;
writeBus(cpu->bus, cpu->fetchedAddress, cpu->fetchedVal);
cpu->acc ^= cpu->fetchedVal;
cpu->status.negative = ((cpu->acc & 0x80) == 0x80);
cpu->status.zero = (cpu->acc == 0x00);
cpu->remainingCycles = cpu->currentOpcode->cycles;
} break;
case STA:
{
writeBus(cpu->bus, cpu->fetchedAddress, cpu->acc);