Move CPU instruction impl to source file
This commit is contained in:
scawful
@@ -1232,6 +1232,485 @@ void CPU::ANDAbsoluteLong(uint32_t address) {
|
||||
SetNegativeFlag(A & 0x80000000);
|
||||
}
|
||||
|
||||
void CPU::ASL(uint16_t address) {
|
||||
uint8_t value = memory.ReadByte(address);
|
||||
SetCarryFlag(!(value & 0x80)); // Set carry flag if bit 7 is set
|
||||
value <<= 1; // Shift left
|
||||
value &= 0xFE; // Clear bit 0
|
||||
memory.WriteByte(address, value);
|
||||
SetNegativeFlag(!value);
|
||||
SetZeroFlag(value);
|
||||
}
|
||||
|
||||
void CPU::BCC(int8_t offset) {
|
||||
if (!GetCarryFlag()) { // If the carry flag is clear
|
||||
PC += offset; // Add the offset to the program counter
|
||||
}
|
||||
}
|
||||
|
||||
// BCS: Branch if carry set
|
||||
void CPU::BCS(int8_t offset) {
|
||||
if (GetCarryFlag()) { // If the carry flag is set
|
||||
PC += offset; // Add the offset to the program counter
|
||||
}
|
||||
}
|
||||
|
||||
// BEQ: Branch if equal (zero set)
|
||||
void CPU::BEQ(int8_t offset) {
|
||||
if (GetZeroFlag()) { // If the zero flag is set
|
||||
PC += offset; // Add the offset to the program counter
|
||||
}
|
||||
}
|
||||
|
||||
// BIT: Bit test
|
||||
void CPU::BIT(uint16_t address) {
|
||||
uint8_t value = memory.ReadByte(address);
|
||||
SetNegativeFlag(value & 0x80);
|
||||
SetOverflowFlag(value & 0x40);
|
||||
SetZeroFlag((A & value) == 0);
|
||||
}
|
||||
|
||||
// BMI: Branch if minus (negative set)
|
||||
void CPU::BMI(int8_t offset) {
|
||||
if (GetNegativeFlag()) { // If the negative flag is set
|
||||
PC += offset; // Add the offset to the program counter
|
||||
}
|
||||
}
|
||||
|
||||
// BNE: Branch if not equal (zero clear)
|
||||
void CPU::BNE(int8_t offset) {
|
||||
if (!GetZeroFlag()) { // If the zero flag is clear
|
||||
PC += offset; // Add the offset to the program counter
|
||||
}
|
||||
}
|
||||
|
||||
// BPL: Branch if plus (negative clear)
|
||||
void CPU::BPL(int8_t offset) {
|
||||
if (!GetNegativeFlag()) { // If the negative flag is clear
|
||||
PC += offset; // Add the offset to the program counter
|
||||
}
|
||||
}
|
||||
|
||||
// BRA: Branch always
|
||||
void CPU::BRA(int8_t offset) { PC += offset; }
|
||||
|
||||
// BRK: Break
|
||||
void CPU::BRK() {
|
||||
PC += 2; // Increment the program counter by 2
|
||||
memory.PushWord(PC);
|
||||
memory.PushByte(status);
|
||||
SetInterruptFlag(true);
|
||||
try {
|
||||
PC = memory.ReadWord(0xFFFE);
|
||||
} catch (const std::exception& e) {
|
||||
std::cout << "BRK: " << e.what() << std::endl;
|
||||
}
|
||||
}
|
||||
|
||||
// BRL: Branch always long
|
||||
void CPU::BRL(int16_t offset) {
|
||||
PC += offset; // Add the offset to the program counter
|
||||
}
|
||||
|
||||
// BVC: Branch if overflow clear
|
||||
void CPU::BVC(int8_t offset) {
|
||||
if (!GetOverflowFlag()) { // If the overflow flag is clear
|
||||
PC += offset; // Add the offset to the program counter
|
||||
}
|
||||
}
|
||||
|
||||
// BVS: Branch if overflow set
|
||||
void CPU::BVS(int8_t offset) {
|
||||
if (GetOverflowFlag()) { // If the overflow flag is set
|
||||
PC += offset; // Add the offset to the program counter
|
||||
}
|
||||
}
|
||||
|
||||
// CLC: Clear carry flag
|
||||
void CPU::CLC() { status &= ~0x01; }
|
||||
|
||||
// CLD: Clear decimal mode
|
||||
void CPU::CLD() { status &= ~0x08; }
|
||||
|
||||
// CLI: Clear interrupt disable flag
|
||||
void CPU::CLI() { status &= ~0x04; }
|
||||
|
||||
// CLV: Clear overflow flag
|
||||
void CPU::CLV() { status &= ~0x40; }
|
||||
|
||||
// CMP: Compare TESTME
|
||||
// n Set if MSB of result is set; else cleared
|
||||
// z Set if result is zero; else cleared
|
||||
// c Set if no borrow; else cleared
|
||||
void CPU::CMP(uint8_t value, bool isImmediate = false) {
|
||||
if (GetAccumulatorSize()) { // 8-bit
|
||||
uint8_t result = isImmediate ? A - value : A - memory.ReadByte(value);
|
||||
SetZeroFlag(result == 0);
|
||||
SetNegativeFlag(result & 0x80);
|
||||
SetCarryFlag(A >= value);
|
||||
} else { // 16-bit
|
||||
uint16_t result = isImmediate ? A - value : A - memory.ReadWord(value);
|
||||
SetZeroFlag(result == 0);
|
||||
SetNegativeFlag(result & 0x8000);
|
||||
SetCarryFlag(A >= value);
|
||||
}
|
||||
}
|
||||
|
||||
// COP: Coprocessor TESTME
|
||||
void CPU::COP() {
|
||||
PC += 2; // Increment the program counter by 2
|
||||
memory.PushWord(PC);
|
||||
memory.PushByte(status);
|
||||
SetInterruptFlag(true);
|
||||
if (E) {
|
||||
PC = memory.ReadWord(0xFFF4);
|
||||
} else {
|
||||
PC = memory.ReadWord(0xFFE4);
|
||||
}
|
||||
SetDecimalFlag(false);
|
||||
}
|
||||
|
||||
// CPX: Compare X register
|
||||
void CPU::CPX(uint16_t value, bool isImmediate = false) {
|
||||
if (GetIndexSize()) { // 8-bit
|
||||
uint8_t memory_value = isImmediate ? value : memory.ReadByte(value);
|
||||
compare(X, memory_value);
|
||||
} else { // 16-bit
|
||||
uint16_t memory_value = isImmediate ? value : memory.ReadWord(value);
|
||||
compare(X, memory_value);
|
||||
}
|
||||
}
|
||||
|
||||
// CPY: Compare Y register
|
||||
void CPU::CPY(uint16_t value, bool isImmediate = false) {
|
||||
if (GetIndexSize()) { // 8-bit
|
||||
uint8_t memory_value = isImmediate ? value : memory.ReadByte(value);
|
||||
compare(Y, memory_value);
|
||||
} else { // 16-bit
|
||||
uint16_t memory_value = isImmediate ? value : memory.ReadWord(value);
|
||||
compare(Y, memory_value);
|
||||
}
|
||||
}
|
||||
|
||||
// DEC: Decrement TESTME
|
||||
void CPU::DEC(uint16_t address) {
|
||||
if (GetAccumulatorSize()) {
|
||||
uint8_t value = memory.ReadByte(address);
|
||||
value--;
|
||||
memory.WriteByte(address, value);
|
||||
SetZeroFlag(value == 0);
|
||||
SetNegativeFlag(value & 0x80);
|
||||
} else {
|
||||
uint16_t value = memory.ReadWord(address);
|
||||
value--;
|
||||
memory.WriteWord(address, value);
|
||||
SetZeroFlag(value == 0);
|
||||
SetNegativeFlag(value & 0x8000);
|
||||
}
|
||||
}
|
||||
|
||||
// DEX: Decrement X register
|
||||
void CPU::DEX() {
|
||||
if (GetIndexSize()) { // 8-bit
|
||||
X = static_cast<uint8_t>(X - 1);
|
||||
SetZeroFlag(X == 0);
|
||||
SetNegativeFlag(X & 0x80);
|
||||
} else { // 16-bit
|
||||
X = static_cast<uint16_t>(X - 1);
|
||||
SetZeroFlag(X == 0);
|
||||
SetNegativeFlag(X & 0x8000);
|
||||
}
|
||||
}
|
||||
|
||||
// DEY: Decrement Y register
|
||||
void CPU::DEY() {
|
||||
if (GetIndexSize()) { // 8-bit
|
||||
Y = static_cast<uint8_t>(Y - 1);
|
||||
SetZeroFlag(Y == 0);
|
||||
SetNegativeFlag(Y & 0x80);
|
||||
} else { // 16-bit
|
||||
Y = static_cast<uint16_t>(Y - 1);
|
||||
SetZeroFlag(Y == 0);
|
||||
SetNegativeFlag(Y & 0x8000);
|
||||
}
|
||||
}
|
||||
|
||||
// EOR: Exclusive OR TESTMEs
|
||||
void CPU::EOR(uint16_t address, bool isImmediate = false) {
|
||||
if (GetAccumulatorSize()) {
|
||||
A ^= isImmediate ? address : memory.ReadByte(address);
|
||||
SetZeroFlag(A == 0);
|
||||
SetNegativeFlag(A & 0x80);
|
||||
} else {
|
||||
A ^= isImmediate ? address : memory.ReadWord(address);
|
||||
SetZeroFlag(A == 0);
|
||||
SetNegativeFlag(A & 0x8000);
|
||||
}
|
||||
}
|
||||
|
||||
// INC: Increment
|
||||
void CPU::INC(uint16_t address) {
|
||||
if (GetAccumulatorSize()) {
|
||||
uint8_t value = memory.ReadByte(address);
|
||||
value++;
|
||||
memory.WriteByte(address, value);
|
||||
SetNegativeFlag(value & 0x80);
|
||||
SetZeroFlag(value == 0);
|
||||
} else {
|
||||
uint16_t value = memory.ReadWord(address);
|
||||
value++;
|
||||
memory.WriteWord(address, value);
|
||||
SetNegativeFlag(value & 0x8000);
|
||||
SetZeroFlag(value == 0);
|
||||
}
|
||||
}
|
||||
|
||||
// INX: Increment X register
|
||||
void CPU::INX() {
|
||||
if (GetIndexSize()) { // 8-bit
|
||||
X = static_cast<uint8_t>(X + 1);
|
||||
SetZeroFlag(X == 0);
|
||||
SetNegativeFlag(X & 0x80);
|
||||
} else { // 16-bit
|
||||
X = static_cast<uint16_t>(X + 1);
|
||||
SetZeroFlag(X == 0);
|
||||
SetNegativeFlag(X & 0x8000);
|
||||
}
|
||||
}
|
||||
|
||||
// INY: Increment Y register
|
||||
void CPU::INY() {
|
||||
if (GetIndexSize()) { // 8-bit
|
||||
Y = static_cast<uint8_t>(Y + 1);
|
||||
SetZeroFlag(Y == 0);
|
||||
SetNegativeFlag(Y & 0x80);
|
||||
} else { // 16-bit
|
||||
Y = static_cast<uint16_t>(Y + 1);
|
||||
SetZeroFlag(Y == 0);
|
||||
SetNegativeFlag(Y & 0x8000);
|
||||
}
|
||||
}
|
||||
|
||||
// JMP: Jump
|
||||
void CPU::JMP(uint16_t address) {
|
||||
PC = address; // Set program counter to the new address
|
||||
}
|
||||
|
||||
// JML: Jump long
|
||||
void CPU::JML(uint32_t address) {
|
||||
// Set the lower 16 bits of PC to the lower 16 bits of the address
|
||||
PC = static_cast<uint8_t>(address & 0xFFFF);
|
||||
// Set the PBR to the upper 8 bits of the address
|
||||
PB = static_cast<uint8_t>((address >> 16) & 0xFF);
|
||||
}
|
||||
|
||||
// JSR: Jump to subroutine
|
||||
void CPU::JSR(uint16_t address) {
|
||||
PC -= 1; // Subtract 1 from program counter
|
||||
memory.PushWord(PC); // Push the program counter onto the stack
|
||||
PC = address; // Set program counter to the new address
|
||||
}
|
||||
|
||||
// JSL: Jump to subroutine long
|
||||
void CPU::JSL(uint32_t address) {
|
||||
PC -= 1; // Subtract 1 from program counter
|
||||
memory.PushLong(PC); // Push the program counter onto the stack as a long
|
||||
// value (24 bits)
|
||||
PC = address; // Set program counter to the new address
|
||||
}
|
||||
|
||||
// LDA: Load accumulator
|
||||
void CPU::LDA(uint16_t address, bool isImmediate = false) {
|
||||
if (GetAccumulatorSize()) {
|
||||
A = isImmediate ? address : memory.ReadByte(address);
|
||||
SetZeroFlag(A == 0);
|
||||
SetNegativeFlag(A & 0x80);
|
||||
} else {
|
||||
A = isImmediate ? memory.ReadWord(PC) : memory.ReadWord(address);
|
||||
SetZeroFlag(A == 0);
|
||||
SetNegativeFlag(A & 0x8000);
|
||||
}
|
||||
}
|
||||
|
||||
// LDX: Load X register
|
||||
void CPU::LDX(uint16_t address, bool isImmediate = false) {
|
||||
if (GetIndexSize()) {
|
||||
X = isImmediate ? address : memory.ReadByte(address);
|
||||
SetZeroFlag(X == 0);
|
||||
SetNegativeFlag(X & 0x80);
|
||||
} else {
|
||||
X = isImmediate ? address : memory.ReadWord(address);
|
||||
SetZeroFlag(X == 0);
|
||||
SetNegativeFlag(X & 0x8000);
|
||||
}
|
||||
}
|
||||
|
||||
// LDY: Load Y register
|
||||
void CPU::LDY(uint16_t address, bool isImmediate = false) {
|
||||
if (GetIndexSize()) {
|
||||
Y = isImmediate ? address : memory.ReadByte(address);
|
||||
SetZeroFlag(Y == 0);
|
||||
SetNegativeFlag(Y & 0x80);
|
||||
} else {
|
||||
Y = isImmediate ? address : memory.ReadWord(address);
|
||||
SetZeroFlag(Y == 0);
|
||||
SetNegativeFlag(Y & 0x8000);
|
||||
}
|
||||
}
|
||||
|
||||
// LSR: Logical shift right
|
||||
void CPU::LSR(uint16_t address) {
|
||||
uint8_t value = memory.ReadByte(address);
|
||||
SetCarryFlag(value & 0x01);
|
||||
value >>= 1;
|
||||
memory.WriteByte(address, value);
|
||||
SetNegativeFlag(false);
|
||||
SetZeroFlag(value == 0);
|
||||
}
|
||||
|
||||
// MVN: Move negative ```
|
||||
// MVP: Move positive ```
|
||||
|
||||
// NOP: No operation
|
||||
void CPU::NOP() {
|
||||
// Do nothing
|
||||
}
|
||||
|
||||
// ORA: Logical OR
|
||||
void CPU::ORA(uint16_t address, bool isImmediate = false) {
|
||||
if (GetAccumulatorSize()) {
|
||||
A |= isImmediate ? address : memory.ReadByte(address);
|
||||
SetZeroFlag(A == 0);
|
||||
SetNegativeFlag(A & 0x80);
|
||||
} else {
|
||||
A |= isImmediate ? address : memory.ReadWord(address);
|
||||
SetZeroFlag(A == 0);
|
||||
SetNegativeFlag(A & 0x8000);
|
||||
}
|
||||
}
|
||||
|
||||
// PEA: Push effective address
|
||||
void CPU::PEA() {
|
||||
uint16_t address = FetchWord();
|
||||
memory.PushWord(address);
|
||||
}
|
||||
|
||||
// PEI: Push effective indirect address
|
||||
void CPU::PEI() {
|
||||
uint16_t address = FetchWord();
|
||||
memory.PushWord(memory.ReadWord(address));
|
||||
}
|
||||
|
||||
// PER: Push effective PC-relative address
|
||||
void CPU::PER() {
|
||||
uint16_t address = FetchWord();
|
||||
memory.PushWord(PC + address);
|
||||
}
|
||||
|
||||
// PHA: Push Accumulator on Stack
|
||||
void CPU::PHA() { memory.PushByte(A); }
|
||||
|
||||
// PHB: Push Data Bank Register on Stack
|
||||
void CPU::PHB() { memory.PushByte(DB); }
|
||||
|
||||
// PHD: Push Program Bank Register on Stack
|
||||
void CPU::PHD() { memory.PushWord(D); }
|
||||
|
||||
// PHK: Push Program Bank Register on Stack
|
||||
void CPU::PHK() { memory.PushByte(PB); }
|
||||
|
||||
// PHP: Push Processor Status Register on Stack
|
||||
void CPU::PHP() { memory.PushByte(status); }
|
||||
|
||||
// PHX: Push X Index Register on Stack
|
||||
void CPU::PHX() { memory.PushByte(X); }
|
||||
|
||||
// PHY: Push Y Index Register on Stack
|
||||
void CPU::PHY() { memory.PushByte(Y); }
|
||||
|
||||
// PLA: Pull Accumulator from Stack
|
||||
void CPU::PLA() {
|
||||
A = memory.PopByte();
|
||||
SetNegativeFlag((A & 0x80) != 0);
|
||||
SetZeroFlag(A == 0);
|
||||
}
|
||||
|
||||
// PLB: Pull data bank register
|
||||
void CPU::PLB() {
|
||||
DB = memory.PopByte();
|
||||
SetNegativeFlag((DB & 0x80) != 0);
|
||||
SetZeroFlag(DB == 0);
|
||||
}
|
||||
|
||||
// Pull Direct Page Register from Stack
|
||||
void CPU::PLD() {
|
||||
D = memory.PopWord();
|
||||
SetNegativeFlag((D & 0x8000) != 0);
|
||||
SetZeroFlag(D == 0);
|
||||
}
|
||||
|
||||
// Pull Processor Status Register from Stack
|
||||
void CPU::PLP() { status = memory.PopByte(); }
|
||||
|
||||
// PLX: Pull X Index Register from Stack
|
||||
void CPU::PLX() {
|
||||
X = memory.PopByte();
|
||||
SetNegativeFlag((A & 0x80) != 0);
|
||||
SetZeroFlag(X == 0);
|
||||
}
|
||||
|
||||
// PHY: Pull Y Index Register from Stack
|
||||
void CPU::PLY() {
|
||||
Y = memory.PopByte();
|
||||
SetNegativeFlag((A & 0x80) != 0);
|
||||
SetZeroFlag(Y == 0);
|
||||
}
|
||||
|
||||
// REP: Reset status bits
|
||||
void CPU::REP() {
|
||||
auto byte = FetchByte();
|
||||
status &= ~byte;
|
||||
}
|
||||
|
||||
// ROL: Rotate left
|
||||
void CPU::ROL(uint16_t address) {
|
||||
uint8_t value = memory.ReadByte(address);
|
||||
uint8_t carry = GetCarryFlag() ? 0x01 : 0x00;
|
||||
SetCarryFlag(value & 0x80);
|
||||
value <<= 1;
|
||||
value |= carry;
|
||||
memory.WriteByte(address, value);
|
||||
SetNegativeFlag(value & 0x80);
|
||||
SetZeroFlag(value == 0);
|
||||
}
|
||||
|
||||
// ROR: Rotate right
|
||||
void CPU::ROR(uint16_t address) {
|
||||
uint8_t value = memory.ReadByte(address);
|
||||
uint8_t carry = GetCarryFlag() ? 0x80 : 0x00;
|
||||
SetCarryFlag(value & 0x01);
|
||||
value >>= 1;
|
||||
value |= carry;
|
||||
memory.WriteByte(address, value);
|
||||
SetNegativeFlag(value & 0x80);
|
||||
SetZeroFlag(value == 0);
|
||||
}
|
||||
|
||||
// RTI: Return from interrupt
|
||||
void CPU::RTI() {
|
||||
status = memory.PopByte();
|
||||
PC = memory.PopWord();
|
||||
}
|
||||
|
||||
// RTL: Return from subroutine long
|
||||
void CPU::RTL() {
|
||||
PC = memory.PopWord();
|
||||
PB = memory.PopByte();
|
||||
}
|
||||
|
||||
// RTS: Return from subroutine
|
||||
void CPU::RTS() { PC = memory.PopWord() + 1; } // ASL: Arithmetic shift left
|
||||
|
||||
void CPU::SBC(uint16_t value, bool isImmediate) {
|
||||
uint16_t operand;
|
||||
if (!GetAccumulatorSize()) { // 16-bit mode
|
||||
@@ -1265,6 +1744,180 @@ void CPU::SBC(uint16_t value, bool isImmediate) {
|
||||
}
|
||||
}
|
||||
|
||||
// SEC: Set carry flag
|
||||
void CPU::SEC() { status |= 0x01; }
|
||||
|
||||
// SED: Set decimal mode
|
||||
void CPU::SED() { status |= 0x08; }
|
||||
|
||||
// SEI: Set interrupt disable flag
|
||||
void CPU::SEI() { status |= 0x04; }
|
||||
|
||||
// SEP: Set status bits
|
||||
void CPU::SEP() {
|
||||
auto byte = FetchByte();
|
||||
status |= byte;
|
||||
}
|
||||
|
||||
// STA: Store accumulator
|
||||
void CPU::STA(uint16_t address) {
|
||||
if (GetAccumulatorSize()) {
|
||||
memory.WriteByte(address, static_cast<uint8_t>(A));
|
||||
} else {
|
||||
memory.WriteWord(address, A);
|
||||
}
|
||||
}
|
||||
|
||||
// TODO: Make this work with the Clock class of the CPU
|
||||
// STP: Stop the clock
|
||||
void CPU::STP() {
|
||||
// During the next phase 2 clock cycle, stop the processors oscillator input
|
||||
// The processor is effectively shut down until a reset occurs (RES` pin).
|
||||
}
|
||||
|
||||
// STX: Store X register
|
||||
void CPU::STX(uint16_t address) {
|
||||
if (GetIndexSize()) {
|
||||
memory.WriteByte(address, static_cast<uint8_t>(X));
|
||||
} else {
|
||||
memory.WriteWord(address, X);
|
||||
}
|
||||
}
|
||||
|
||||
// STY: Store Y register
|
||||
void CPU::STY(uint16_t address) {
|
||||
if (GetIndexSize()) {
|
||||
memory.WriteByte(address, static_cast<uint8_t>(Y));
|
||||
} else {
|
||||
memory.WriteWord(address, Y);
|
||||
}
|
||||
}
|
||||
|
||||
// STZ: Store zero
|
||||
void CPU::STZ(uint16_t address) {
|
||||
if (GetAccumulatorSize()) {
|
||||
memory.WriteByte(address, 0x00);
|
||||
} else {
|
||||
memory.WriteWord(address, 0x0000);
|
||||
}
|
||||
}
|
||||
|
||||
// TAX: Transfer accumulator to X
|
||||
void CPU::TAX() {
|
||||
X = A;
|
||||
SetZeroFlag(X == 0);
|
||||
SetNegativeFlag(X & 0x80);
|
||||
}
|
||||
|
||||
// TAY: Transfer accumulator to Y
|
||||
void CPU::TAY() {
|
||||
Y = A;
|
||||
SetZeroFlag(Y == 0);
|
||||
SetNegativeFlag(Y & 0x80);
|
||||
}
|
||||
|
||||
// TCD: Transfer accumulator to direct page register
|
||||
void CPU::TCD() {
|
||||
D = A;
|
||||
SetZeroFlag(D == 0);
|
||||
SetNegativeFlag(D & 0x80);
|
||||
}
|
||||
|
||||
// TCS: Transfer accumulator to stack pointer
|
||||
void CPU::TCS() { memory.SetSP(A); }
|
||||
|
||||
// TDC: Transfer direct page register to accumulator
|
||||
void CPU::TDC() {
|
||||
A = D;
|
||||
SetZeroFlag(A == 0);
|
||||
SetNegativeFlag(A & 0x80);
|
||||
}
|
||||
|
||||
// TRB: Test and reset bits
|
||||
void CPU::TRB(uint16_t address) {
|
||||
uint8_t value = memory.ReadByte(address);
|
||||
SetZeroFlag((A & value) == 0);
|
||||
value &= ~A;
|
||||
memory.WriteByte(address, value);
|
||||
}
|
||||
|
||||
// TSB: Test and set bits
|
||||
void CPU::TSB(uint16_t address) {
|
||||
uint8_t value = memory.ReadByte(address);
|
||||
SetZeroFlag((A & value) == 0);
|
||||
value |= A;
|
||||
memory.WriteByte(address, value);
|
||||
}
|
||||
|
||||
// TSC: Transfer stack pointer to accumulator
|
||||
void CPU::TSC() {
|
||||
A = SP();
|
||||
SetZeroFlag(A == 0);
|
||||
SetNegativeFlag(A & 0x80);
|
||||
}
|
||||
|
||||
// TSX: Transfer stack pointer to X
|
||||
void CPU::TSX() {
|
||||
X = SP();
|
||||
SetZeroFlag(X == 0);
|
||||
SetNegativeFlag(X & 0x80);
|
||||
}
|
||||
|
||||
// TXA: Transfer X to accumulator
|
||||
void CPU::TXA() {
|
||||
A = X;
|
||||
SetZeroFlag(A == 0);
|
||||
SetNegativeFlag(A & 0x80);
|
||||
}
|
||||
|
||||
// TXS: Transfer X to stack pointer
|
||||
void CPU::TXS() { memory.SetSP(X); }
|
||||
|
||||
// TXY: Transfer X to Y
|
||||
void CPU::TXY() {
|
||||
X = Y;
|
||||
SetZeroFlag(X == 0);
|
||||
SetNegativeFlag(X & 0x80);
|
||||
}
|
||||
|
||||
// TYA: Transfer Y to accumulator
|
||||
void CPU::TYA() {
|
||||
A = Y;
|
||||
SetZeroFlag(A == 0);
|
||||
SetNegativeFlag(A & 0x80);
|
||||
}
|
||||
|
||||
// TYX: Transfer Y to X
|
||||
void CPU::TYX() {
|
||||
Y = X;
|
||||
SetZeroFlag(Y == 0);
|
||||
SetNegativeFlag(Y & 0x80);
|
||||
}
|
||||
|
||||
// TODO: Make this communicate with the SNES class
|
||||
// WAI: Wait for interrupt TESTME
|
||||
void CPU::WAI() {
|
||||
// Pull the RDY pin low
|
||||
// Power consumption is reduced(?)
|
||||
// RDY remains low until an external hardware interupt
|
||||
// (NMI, IRQ, ABORT, or RESET) is received from the SNES class
|
||||
}
|
||||
|
||||
// XBA: Exchange B and A accumulator
|
||||
void CPU::XBA() {
|
||||
uint8_t lowByte = A & 0xFF;
|
||||
uint8_t highByte = (A >> 8) & 0xFF;
|
||||
A = (lowByte << 8) | highByte;
|
||||
}
|
||||
|
||||
// XCE: Exchange Carry and Emulation Flags
|
||||
void CPU::XCE() {
|
||||
uint8_t carry = status & 0x01;
|
||||
status &= ~0x01;
|
||||
status |= E;
|
||||
E = carry;
|
||||
}
|
||||
|
||||
} // namespace emu
|
||||
} // namespace app
|
||||
} // namespace yaze
|
||||
Reference in New Issue
Block a user