1303 lines
25 KiB
C++
1303 lines
25 KiB
C++
/************************
|
|
Add/substract operations
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*************************/
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void Cpu::Add8(uint8_t value)
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|
{
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uint32_t result;
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if(CheckFlag(ProcFlags::Decimal)) {
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result = (_state.A & 0x0F) + (value & 0x0F) + (_state.PS & ProcFlags::Carry);
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if(result > 0x09) result += 0x06;
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result = (_state.A & 0xF0) + (value & 0xF0) + (result > 0x0F ? 0x10 : 0) + (result & 0x0F);
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} else {
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result = (_state.A & 0xFF) + value + (_state.PS & ProcFlags::Carry);
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}
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if(~(_state.A ^ value) & (_state.A ^ result) & 0x80) {
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SetFlags(ProcFlags::Overflow);
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} else {
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ClearFlags(ProcFlags::Overflow);
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}
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if(CheckFlag(ProcFlags::Decimal) && result > 0x9F) {
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result += 0x60;
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}
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ClearFlags(ProcFlags::Carry | ProcFlags::Negative | ProcFlags::Zero);
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SetZeroNegativeFlags((uint8_t)result);
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if(result > 0xFF) {
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SetFlags(ProcFlags::Carry);
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}
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_state.A = (_state.A & 0xFF00) | (uint8_t)result;
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}
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void Cpu::Add16(uint16_t value)
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{
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uint32_t result;
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if(CheckFlag(ProcFlags::Decimal)) {
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result = (_state.A & 0x0F) + (value & 0x0F) + (_state.PS & ProcFlags::Carry);
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if(result > 0x09) result += 0x06;
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result = (_state.A & 0xF0) + (value & 0xF0) + (result > 0x0F ? 0x10 : 0) + (result & 0x0F);
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if(result > 0x9F) result += 0x60;
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result = (_state.A & 0xF00) + (value & 0xF00) + (result > 0xFF ? 0x100 : 0) + (result & 0xFF);
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if(result > 0x9FF) result += 0x600;
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result = (_state.A & 0xF000) + (value & 0xF000) + (result > 0xFFF ? 0x1000 : 0) + (result & 0xFFF);
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} else {
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result = _state.A + value + (_state.PS & ProcFlags::Carry);
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}
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if(~(_state.A ^ value) & (_state.A ^ result) & 0x8000) {
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SetFlags(ProcFlags::Overflow);
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} else {
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ClearFlags(ProcFlags::Overflow);
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}
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if(CheckFlag(ProcFlags::Decimal) && result > 0x9FFF) {
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result += 0x6000;
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}
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ClearFlags(ProcFlags::Carry | ProcFlags::Negative | ProcFlags::Zero);
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SetZeroNegativeFlags((uint16_t)result);
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if(result > 0xFFFF) {
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SetFlags(ProcFlags::Carry);
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}
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_state.A = (uint16_t)result;
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}
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void Cpu::ADC()
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{
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if(CheckFlag(ProcFlags::MemoryMode8)) {
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Add8(GetByteValue());
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} else {
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Add16(GetWordValue());
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}
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}
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void Cpu::Sub8(uint8_t value)
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{
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int32_t result;
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if(CheckFlag(ProcFlags::Decimal)) {
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result = (_state.A & 0x0F) + (value & 0x0F) + (_state.PS & ProcFlags::Carry);
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if(result <= 0x0F) result -= 0x06;
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result = (_state.A & 0xF0) + (value & 0xF0) + (result > 0x0F ? 0x10 : 0) + (result & 0x0F);
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} else {
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result = (_state.A & 0xFF) + value + (_state.PS & ProcFlags::Carry);
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}
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if(~(_state.A ^ value) & (_state.A ^ result) & 0x80) {
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SetFlags(ProcFlags::Overflow);
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} else {
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ClearFlags(ProcFlags::Overflow);
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}
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if(CheckFlag(ProcFlags::Decimal) && result <= 0xFF) {
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result -= 0x60;
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}
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ClearFlags(ProcFlags::Carry | ProcFlags::Negative | ProcFlags::Zero);
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SetZeroNegativeFlags((uint8_t)result);
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if(result > 0xFF) {
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SetFlags(ProcFlags::Carry);
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}
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_state.A = (_state.A & 0xFF00) | (uint8_t)result;
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}
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void Cpu::Sub16(uint16_t value)
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{
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int32_t result;
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if(CheckFlag(ProcFlags::Decimal)) {
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result = (_state.A & 0x0F) + (value & 0x0F) + (_state.PS & ProcFlags::Carry);
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if(result <= 0x0F) result -= 0x06;
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result = (_state.A & 0xF0) + (value & 0xF0) + (result > 0x0F ? 0x10 : 0) + (result & 0x0F);
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if(result <= 0xFF) result -= 0x60;
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result = (_state.A & 0xF00) + (value & 0xF00) + (result > 0xFF ? 0x100 : 0) + (result & 0xFF);
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if(result <= 0xFFF) result -= 0x600;
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result = (_state.A & 0xF000) + (value & 0xF000) + (result > 0xFFF ? 0x1000 : 0) + (result & 0xFFF);
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} else {
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result = _state.A + value + (_state.PS & ProcFlags::Carry);
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}
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if(~(_state.A ^ value) & (_state.A ^ result) & 0x8000) {
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SetFlags(ProcFlags::Overflow);
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} else {
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ClearFlags(ProcFlags::Overflow);
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}
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if(CheckFlag(ProcFlags::Decimal) && result <= 0xFFFF) {
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result -= 0x6000;
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}
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ClearFlags(ProcFlags::Carry | ProcFlags::Negative | ProcFlags::Zero);
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SetZeroNegativeFlags((uint16_t)result);
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if(result > 0xFFFF) {
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SetFlags(ProcFlags::Carry);
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}
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_state.A = (uint16_t)result;
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}
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void Cpu::SBC()
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{
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if(CheckFlag(ProcFlags::MemoryMode8)) {
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Sub8(~GetByteValue());
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} else {
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Sub16(~GetWordValue());
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}
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}
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/****************
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Branch operations
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****************/
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void Cpu::BCC()
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{
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BranchRelative(!CheckFlag(ProcFlags::Carry));
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}
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void Cpu::BCS()
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{
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BranchRelative(CheckFlag(ProcFlags::Carry));
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}
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void Cpu::BEQ()
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{
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BranchRelative(CheckFlag(ProcFlags::Zero));
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}
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void Cpu::BMI()
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{
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BranchRelative(CheckFlag(ProcFlags::Negative));
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}
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void Cpu::BNE()
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{
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BranchRelative(!CheckFlag(ProcFlags::Zero));
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}
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void Cpu::BPL()
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{
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BranchRelative(!CheckFlag(ProcFlags::Negative));
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}
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void Cpu::BRA()
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{
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BranchRelative(true);
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}
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void Cpu::BRL()
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{
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_state.PC = (uint16_t)(_state.PC + (int16_t)_operand);
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IdleTakeBranch();
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}
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void Cpu::BVC()
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{
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BranchRelative(!CheckFlag(ProcFlags::Overflow));
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}
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void Cpu::BVS()
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{
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BranchRelative(CheckFlag(ProcFlags::Overflow));
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}
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void Cpu::BranchRelative(bool branch)
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{
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if(branch) {
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int8_t offset = _operand;
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Idle();
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if(_state.EmulationMode && ((uint16_t)(_state.PC + offset) & 0xFF00) != (_state.PC & 0xFF00)) {
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//Extra cycle in emulation mode if crossing a page
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Idle();
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}
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_state.PC = (uint16_t)(_state.PC + offset);
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IdleTakeBranch();
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}
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}
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/***************************
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Set/clear flag instructions
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****************************/
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void Cpu::CLC()
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{
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ClearFlags(ProcFlags::Carry);
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}
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void Cpu::CLD()
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{
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ClearFlags(ProcFlags::Decimal);
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}
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void Cpu::CLI()
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{
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ClearFlags(ProcFlags::IrqDisable);
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}
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void Cpu::CLV()
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{
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ClearFlags(ProcFlags::Overflow);
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}
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void Cpu::SEC()
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{
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SetFlags(ProcFlags::Carry);
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}
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void Cpu::SED()
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{
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SetFlags(ProcFlags::Decimal);
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}
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void Cpu::SEI()
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{
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SetFlags(ProcFlags::IrqDisable);
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}
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void Cpu::REP()
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{
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Idle();
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ClearFlags((uint8_t)_operand);
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}
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void Cpu::SEP()
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{
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Idle();
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SetFlags((uint8_t)_operand);
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if(CheckFlag(ProcFlags::IndexMode8)) {
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//Truncate X/Y when 8-bit indexes are enabled
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_state.Y &= 0xFF;
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_state.X &= 0xFF;
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}
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}
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/******************************
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Increment/decrement operations
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*******************************/
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void Cpu::DEX()
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{
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IncDecReg(_state.X, -1);
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}
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void Cpu::DEY()
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{
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IncDecReg(_state.Y, -1);
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}
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void Cpu::INX()
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{
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IncDecReg(_state.X, 1);
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}
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void Cpu::INY()
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{
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IncDecReg(_state.Y, 1);
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}
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void Cpu::DEC()
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{
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IncDec(-1);
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}
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void Cpu::INC()
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{
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IncDec(1);
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}
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void Cpu::DEC_Acc()
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{
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SetRegister(_state.A, _state.A - 1, CheckFlag(ProcFlags::MemoryMode8));
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}
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void Cpu::INC_Acc()
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{
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SetRegister(_state.A, _state.A + 1, CheckFlag(ProcFlags::MemoryMode8));
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}
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void Cpu::IncDecReg(uint16_t ®, int8_t offset)
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{
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SetRegister(reg, reg + offset, CheckFlag(ProcFlags::IndexMode8));
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}
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void Cpu::IncDec(int8_t offset)
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{
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if(CheckFlag(ProcFlags::MemoryMode8)) {
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uint8_t value = GetByteValue() + offset;
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SetZeroNegativeFlags(value);
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Idle();
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Write(_operand, value);
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} else {
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uint16_t value = GetWordValue() + offset;
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SetZeroNegativeFlags(value);
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Idle();
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WriteWord(_operand, value);
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}
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}
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/********************
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Compare instructions
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*********************/
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void Cpu::Compare(uint16_t reg, bool eightBitMode)
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{
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if(eightBitMode) {
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uint8_t value = GetByteValue();
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if((uint8_t)reg >= value) {
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SetFlags(ProcFlags::Carry);
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} else {
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ClearFlags(ProcFlags::Carry);
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}
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uint8_t result = (uint8_t)reg - value;
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SetZeroNegativeFlags(result);
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} else {
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uint16_t value = GetWordValue();
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if(reg >= value) {
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SetFlags(ProcFlags::Carry);
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} else {
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ClearFlags(ProcFlags::Carry);
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}
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uint16_t result = reg - value;
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SetZeroNegativeFlags(result);
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}
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}
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void Cpu::CMP()
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{
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Compare(_state.A, CheckFlag(ProcFlags::MemoryMode8));
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}
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void Cpu::CPX()
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{
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Compare(_state.X, CheckFlag(ProcFlags::IndexMode8));
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}
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void Cpu::CPY()
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{
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Compare(_state.Y, CheckFlag(ProcFlags::IndexMode8));
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}
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/*****************
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Jump instructions
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******************/
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void Cpu::JML()
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{
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_state.K = (_operand >> 16) & 0xFF;
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_state.PC = (uint16_t)_operand;
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IdleEndJump();
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}
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void Cpu::JMP()
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{
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_state.PC = (uint16_t)_operand;
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IdleEndJump();
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}
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void Cpu::JSL()
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{
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PushByte(_state.K);
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Idle();
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PushWord(_state.PC - 1);
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_state.K = (_operand >> 16) & 0xFF;
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_state.PC = (uint16_t)_operand;
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IdleEndJump();
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}
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void Cpu::JSR()
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{
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PushWord(_state.PC - 1);
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_state.PC = (uint16_t)_operand;
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IdleEndJump();
|
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}
|
|
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void Cpu::RTI()
|
|
{
|
|
Idle();
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Idle();
|
|
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if(_state.EmulationMode) {
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SetPS(PopByte());
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_state.PC = PopWord();
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} else {
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SetPS(PopByte());
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_state.PC = PopWord();
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_state.K = PopByte();
|
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}
|
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IdleEndJump();
|
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}
|
|
|
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void Cpu::RTL()
|
|
{
|
|
Idle();
|
|
Idle();
|
|
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_state.PC = PopWord();
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_state.PC++;
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_state.K = PopByte();
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IdleEndJump();
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}
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void Cpu::RTS()
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{
|
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Idle();
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Idle();
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|
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_state.PC = PopWord();
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Idle();
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_state.PC++;
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IdleEndJump();
|
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}
|
|
|
|
/**********
|
|
Interrupts
|
|
***********/
|
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void Cpu::ProcessInterrupt(uint16_t vector, bool forHardwareInterrupt)
|
|
{
|
|
if(forHardwareInterrupt) {
|
|
//IRQ/NMI waste 2 cycles here. BRK/COP do not (because they do those 2 cycles while loading the OP code + signature byte)
|
|
ReadCode(_state.PC);
|
|
Idle();
|
|
}
|
|
|
|
if(_state.EmulationMode) {
|
|
PushWord(_state.PC);
|
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PushByte(_state.PS | 0x20);
|
|
|
|
SetFlags(ProcFlags::IrqDisable);
|
|
ClearFlags(ProcFlags::Decimal);
|
|
|
|
_state.K = 0;
|
|
_state.PC = ReadVector(vector);
|
|
} else {
|
|
PushByte(_state.K);
|
|
PushWord(_state.PC);
|
|
PushByte(_state.PS);
|
|
|
|
SetFlags(ProcFlags::IrqDisable);
|
|
ClearFlags(ProcFlags::Decimal);
|
|
|
|
_state.K = 0;
|
|
_state.PC = ReadVector(vector);
|
|
}
|
|
}
|
|
|
|
void Cpu::BRK()
|
|
{
|
|
ProcessInterrupt(_state.EmulationMode ? Cpu::LegacyIrqVector : Cpu::BreakVector, false);
|
|
}
|
|
|
|
void Cpu::COP()
|
|
{
|
|
ProcessInterrupt(_state.EmulationMode ? Cpu::LegacyCoprocessorVector : Cpu::CoprocessorVector, false);
|
|
}
|
|
|
|
/******************
|
|
Bitwise operations
|
|
*******************/
|
|
void Cpu::AND()
|
|
{
|
|
if(CheckFlag(ProcFlags::MemoryMode8)) {
|
|
SetRegister(_state.A, _state.A & GetByteValue(), true);
|
|
} else {
|
|
SetRegister(_state.A, _state.A & GetWordValue(), false);
|
|
}
|
|
}
|
|
|
|
void Cpu::EOR()
|
|
{
|
|
if(CheckFlag(ProcFlags::MemoryMode8)) {
|
|
SetRegister(_state.A, _state.A ^ GetByteValue(), true);
|
|
} else {
|
|
SetRegister(_state.A, _state.A ^ GetWordValue(), false);
|
|
}
|
|
}
|
|
|
|
void Cpu::ORA()
|
|
{
|
|
if(CheckFlag(ProcFlags::MemoryMode8)) {
|
|
SetRegister(_state.A, _state.A | GetByteValue(), true);
|
|
} else {
|
|
SetRegister(_state.A, _state.A | GetWordValue(), false);
|
|
}
|
|
}
|
|
|
|
/****************
|
|
Shift operations
|
|
*****************/
|
|
template<typename T> T Cpu::ShiftLeft(T value)
|
|
{
|
|
T result = value << 1;
|
|
if(value & (1 << (sizeof(T) * 8 - 1))) {
|
|
SetFlags(ProcFlags::Carry);
|
|
} else {
|
|
ClearFlags(ProcFlags::Carry);
|
|
}
|
|
SetZeroNegativeFlags(result);
|
|
return result;
|
|
}
|
|
|
|
template<typename T> T Cpu::RollLeft(T value)
|
|
{
|
|
T result = value << 1 | (_state.PS & ProcFlags::Carry);
|
|
if(value & (1 << (sizeof(T) * 8 - 1))) {
|
|
SetFlags(ProcFlags::Carry);
|
|
} else {
|
|
ClearFlags(ProcFlags::Carry);
|
|
}
|
|
SetZeroNegativeFlags(result);
|
|
return result;
|
|
}
|
|
|
|
template<typename T> T Cpu::ShiftRight(T value)
|
|
{
|
|
T result = value >> 1;
|
|
if(value & 0x01) {
|
|
SetFlags(ProcFlags::Carry);
|
|
} else {
|
|
ClearFlags(ProcFlags::Carry);
|
|
}
|
|
SetZeroNegativeFlags(result);
|
|
return result;
|
|
}
|
|
|
|
template<typename T> T Cpu::RollRight(T value)
|
|
{
|
|
T result = value >> 1 | ((_state.PS & 0x01) << (sizeof(T) * 8 - 1));
|
|
if(value & 0x01) {
|
|
SetFlags(ProcFlags::Carry);
|
|
} else {
|
|
ClearFlags(ProcFlags::Carry);
|
|
}
|
|
SetZeroNegativeFlags(result);
|
|
return result;
|
|
}
|
|
|
|
void Cpu::ASL_Acc()
|
|
{
|
|
if(CheckFlag(ProcFlags::MemoryMode8)) {
|
|
_state.A = (_state.A & 0xFF00) | (ShiftLeft<uint8_t>((uint8_t)_state.A));
|
|
} else {
|
|
_state.A = ShiftLeft<uint16_t>(_state.A);
|
|
}
|
|
}
|
|
|
|
void Cpu::ASL()
|
|
{
|
|
if(CheckFlag(ProcFlags::MemoryMode8)) {
|
|
uint8_t value = GetByteValue();
|
|
Idle();
|
|
Write(_operand, ShiftLeft<uint8_t>(value));
|
|
} else {
|
|
uint16_t value = GetWordValue();
|
|
Idle();
|
|
WriteWord(_operand, ShiftLeft<uint16_t>(value));
|
|
}
|
|
}
|
|
|
|
void Cpu::LSR_Acc()
|
|
{
|
|
if(CheckFlag(ProcFlags::MemoryMode8)) {
|
|
_state.A = (_state.A & 0xFF00) | ShiftRight<uint8_t>((uint8_t)_state.A);
|
|
} else {
|
|
_state.A = ShiftRight<uint16_t>(_state.A);
|
|
}
|
|
}
|
|
|
|
void Cpu::LSR()
|
|
{
|
|
if(CheckFlag(ProcFlags::MemoryMode8)) {
|
|
uint8_t value = GetByteValue();
|
|
Idle();
|
|
Write(_operand, ShiftRight<uint8_t>(value));
|
|
} else {
|
|
uint16_t value = GetWordValue();
|
|
Idle();
|
|
WriteWord(_operand, ShiftRight<uint16_t>(value));
|
|
}
|
|
}
|
|
|
|
void Cpu::ROL_Acc()
|
|
{
|
|
if(CheckFlag(ProcFlags::MemoryMode8)) {
|
|
_state.A = (_state.A & 0xFF00) | RollLeft<uint8_t>((uint8_t)_state.A);
|
|
} else {
|
|
_state.A = RollLeft<uint16_t>(_state.A);
|
|
}
|
|
}
|
|
|
|
void Cpu::ROL()
|
|
{
|
|
if(CheckFlag(ProcFlags::MemoryMode8)) {
|
|
uint8_t value = GetByteValue();
|
|
Idle();
|
|
Write(_operand, RollLeft<uint8_t>(value));
|
|
} else {
|
|
uint16_t value = GetWordValue();
|
|
Idle();
|
|
WriteWord(_operand, RollLeft<uint16_t>(value));
|
|
}
|
|
}
|
|
|
|
void Cpu::ROR_Acc()
|
|
{
|
|
if(CheckFlag(ProcFlags::MemoryMode8)) {
|
|
_state.A = (_state.A & 0xFF00) | RollRight<uint8_t>((uint8_t)_state.A);
|
|
} else {
|
|
_state.A = RollRight<uint16_t>(_state.A);
|
|
}
|
|
}
|
|
|
|
void Cpu::ROR()
|
|
{
|
|
if(CheckFlag(ProcFlags::MemoryMode8)) {
|
|
uint8_t value = GetByteValue();
|
|
Idle();
|
|
Write(_operand, RollRight<uint8_t>(value));
|
|
} else {
|
|
uint16_t value = GetWordValue();
|
|
Idle();
|
|
WriteWord(_operand, RollRight<uint16_t>(value));
|
|
}
|
|
}
|
|
|
|
/***************
|
|
Move operations
|
|
****************/
|
|
void Cpu::MVN()
|
|
{
|
|
_state.DBR = _operand & 0xFF;
|
|
uint32_t destBank = _state.DBR << 16;
|
|
uint32_t srcBank = (_operand << 8) & 0xFF0000;
|
|
|
|
uint8_t value = ReadData(srcBank | _state.X);
|
|
Write(destBank | _state.Y, value);
|
|
|
|
Idle();
|
|
Idle();
|
|
|
|
_state.X++;
|
|
_state.Y++;
|
|
if(CheckFlag(ProcFlags::IndexMode8)) {
|
|
_state.X &= 0xFF;
|
|
_state.Y &= 0xFF;
|
|
}
|
|
|
|
_state.A--;
|
|
|
|
if(_state.A != 0xFFFF) {
|
|
//Operation isn't done, set the PC back to the start of the instruction
|
|
_state.PC -= 3;
|
|
}
|
|
}
|
|
|
|
void Cpu::MVP()
|
|
{
|
|
_state.DBR = _operand & 0xFF;
|
|
uint32_t destBank = _state.DBR << 16;
|
|
uint32_t srcBank = (_operand << 8) & 0xFF0000;
|
|
|
|
uint8_t value = ReadData(srcBank | _state.X);
|
|
Write(destBank | _state.Y, value);
|
|
|
|
Idle();
|
|
Idle();
|
|
|
|
_state.X--;
|
|
_state.Y--;
|
|
if(CheckFlag(ProcFlags::IndexMode8)) {
|
|
_state.X &= 0xFF;
|
|
_state.Y &= 0xFF;
|
|
}
|
|
|
|
_state.A--;
|
|
|
|
if(_state.A != 0xFFFF) {
|
|
//Operation isn't done, set the PC back to the start of the instruction
|
|
_state.PC -= 3;
|
|
}
|
|
}
|
|
|
|
/********************
|
|
Push/pull operations
|
|
*********************/
|
|
void Cpu::PEA()
|
|
{
|
|
//Push Effective Address
|
|
PushWord((uint16_t)_operand);
|
|
}
|
|
|
|
void Cpu::PEI()
|
|
{
|
|
//Push Effective Indirect address
|
|
PushWord(ReadDataWord(_operand));
|
|
}
|
|
|
|
void Cpu::PER()
|
|
{
|
|
//Push Effective Relative address
|
|
PushWord((uint16_t)((int16_t)_operand + _state.PC));
|
|
}
|
|
|
|
void Cpu::PHB()
|
|
{
|
|
Idle();
|
|
PushByte(_state.DBR);
|
|
}
|
|
|
|
void Cpu::PHD()
|
|
{
|
|
Idle();
|
|
PushWord(_state.D);
|
|
}
|
|
|
|
void Cpu::PHK()
|
|
{
|
|
//"PHP, PHK, PHP, PLB, and PLP push and pull one byte from the stack"
|
|
Idle();
|
|
PushByte(_state.K);
|
|
}
|
|
|
|
void Cpu::PHP()
|
|
{
|
|
//"PHP, PHK, PHP, PLB, and PLP push and pull one byte from the stack"
|
|
Idle();
|
|
PushByte(_state.PS);
|
|
}
|
|
|
|
void Cpu::PLB()
|
|
{
|
|
//"PHP, PHK, PHP, PLB, and PLP push and pull one byte from the stack"
|
|
Idle();
|
|
Idle();
|
|
SetRegister(_state.DBR, PopByte());
|
|
}
|
|
|
|
void Cpu::PLD()
|
|
{
|
|
//"PHD and PLD push and pull two bytes from the stack."
|
|
Idle();
|
|
Idle();
|
|
SetRegister(_state.D, PopWord(), false);
|
|
}
|
|
|
|
void Cpu::PLP()
|
|
{
|
|
//"For PLP, (all of) the flags are pulled from the stack. Note that when the e flag is 1, the m and x flag are forced to 1, so after the PLP, both flags will still be 1 no matter what value is pulled from the stack."
|
|
Idle();
|
|
Idle();
|
|
if(_state.EmulationMode) {
|
|
SetPS(PopByte() | ProcFlags::MemoryMode8 | ProcFlags::IndexMode8);
|
|
} else {
|
|
SetPS(PopByte());
|
|
}
|
|
}
|
|
|
|
void Cpu::PHA()
|
|
{
|
|
//"When the m flag is 0, PHA and PLA push and pull a 16-bit value, and when the m flag is 1, PHA and PLA push and pull an 8-bit value. "
|
|
Idle();
|
|
PushRegister(_state.A, CheckFlag(ProcFlags::MemoryMode8));
|
|
}
|
|
|
|
void Cpu::PHX()
|
|
{
|
|
Idle();
|
|
PushRegister(_state.X, CheckFlag(ProcFlags::IndexMode8));
|
|
}
|
|
|
|
void Cpu::PHY()
|
|
{
|
|
Idle();
|
|
PushRegister(_state.Y, CheckFlag(ProcFlags::IndexMode8));
|
|
}
|
|
|
|
void Cpu::PLA()
|
|
{
|
|
//"When the m flag is 0, PHA and PLA push and pull a 16-bit value, and when the m flag is 1, PHA and PLA push and pull an 8-bit value."
|
|
Idle();
|
|
Idle();
|
|
PullRegister(_state.A, CheckFlag(ProcFlags::MemoryMode8));
|
|
}
|
|
|
|
void Cpu::PLX()
|
|
{
|
|
Idle();
|
|
Idle();
|
|
PullRegister(_state.X, CheckFlag(ProcFlags::IndexMode8));
|
|
}
|
|
|
|
void Cpu::PLY()
|
|
{
|
|
Idle();
|
|
Idle();
|
|
PullRegister(_state.Y, CheckFlag(ProcFlags::IndexMode8));
|
|
}
|
|
|
|
void Cpu::PushRegister(uint16_t reg, bool eightBitMode)
|
|
{
|
|
//"When the x flag is 0, PHX, PHY, PLX, and PLY push and pull a 16-bit value, and when the x flag is 1, PHX, PHY, PLX, and PLY push and pull an 8-bit value."
|
|
if(eightBitMode) {
|
|
PushByte((uint8_t)reg);
|
|
} else {
|
|
PushWord(reg);
|
|
}
|
|
}
|
|
|
|
void Cpu::PullRegister(uint16_t ®, bool eightBitMode)
|
|
{
|
|
//"When the x flag is 0, PHX, PHY, PLX, and PLY push and pull a 16-bit value, and when the x flag is 1, PHX, PHY, PLX, and PLY push and pull an 8-bit value."
|
|
if(eightBitMode) {
|
|
SetRegister(reg, PopByte(), true);
|
|
} else {
|
|
SetRegister(reg, PopWord(), false);
|
|
}
|
|
}
|
|
|
|
/*********************
|
|
Store/load operations
|
|
**********************/
|
|
void Cpu::LoadRegister(uint16_t ®, bool eightBitMode)
|
|
{
|
|
if(eightBitMode) {
|
|
SetRegister(reg, GetByteValue(), true);
|
|
} else {
|
|
SetRegister(reg, GetWordValue(), false);
|
|
}
|
|
}
|
|
|
|
void Cpu::StoreRegister(uint16_t val, bool eightBitMode)
|
|
{
|
|
if(eightBitMode) {
|
|
Write(_operand, (uint8_t)val);
|
|
} else {
|
|
WriteWord(_operand, val);
|
|
}
|
|
}
|
|
|
|
void Cpu::LDA()
|
|
{
|
|
//"When the m flag is 0, LDA, STA, and STZ are 16-bit operations"
|
|
LoadRegister(_state.A, CheckFlag(ProcFlags::MemoryMode8));
|
|
}
|
|
|
|
void Cpu::LDX()
|
|
{
|
|
//"When the x flag is 0, LDX, LDY, STX, and STY are 16-bit operations"
|
|
LoadRegister(_state.X, CheckFlag(ProcFlags::IndexMode8));
|
|
}
|
|
|
|
void Cpu::LDY()
|
|
{
|
|
//"When the x flag is 0, LDX, LDY, STX, and STY are 16-bit operations"
|
|
LoadRegister(_state.Y, CheckFlag(ProcFlags::IndexMode8));
|
|
}
|
|
|
|
void Cpu::STA()
|
|
{
|
|
//"When the m flag is 0, LDA, STA, and STZ are 16-bit operations"
|
|
StoreRegister(_state.A, CheckFlag(ProcFlags::MemoryMode8));
|
|
}
|
|
|
|
void Cpu::STX()
|
|
{
|
|
//"When the x flag is 0, LDX, LDY, STX, and STY are 16-bit operations"
|
|
StoreRegister(_state.X, CheckFlag(ProcFlags::IndexMode8));
|
|
}
|
|
|
|
void Cpu::STY()
|
|
{
|
|
//"When the x flag is 0, LDX, LDY, STX, and STY are 16-bit operations"
|
|
StoreRegister(_state.Y, CheckFlag(ProcFlags::IndexMode8));
|
|
}
|
|
|
|
void Cpu::STZ()
|
|
{
|
|
//"When the m flag is 0, LDA, STA, and STZ are 16-bit operations"
|
|
StoreRegister(0, CheckFlag(ProcFlags::MemoryMode8));
|
|
}
|
|
|
|
/*******************
|
|
Bit test operations
|
|
********************/
|
|
template<typename T> void Cpu::TestBits(T value, bool alterZeroFlagOnly)
|
|
{
|
|
if(alterZeroFlagOnly) {
|
|
//"Immediate addressing only affects the z flag (with the result of the bitwise And), but does not affect the n and v flags."
|
|
if(((T)_state.A & value) == 0) {
|
|
SetFlags(ProcFlags::Zero);
|
|
} else {
|
|
ClearFlags(ProcFlags::Zero);
|
|
}
|
|
} else {
|
|
ClearFlags(ProcFlags::Zero | ProcFlags::Overflow | ProcFlags::Negative);
|
|
|
|
if(((T)_state.A & value) == 0) {
|
|
SetFlags(ProcFlags::Zero);
|
|
}
|
|
|
|
if(value & (1 << (sizeof(T) * 8 - 2))) {
|
|
SetFlags(ProcFlags::Overflow);
|
|
}
|
|
if(value & (1 << (sizeof(T) * 8 - 1))) {
|
|
SetFlags(ProcFlags::Negative);
|
|
}
|
|
}
|
|
}
|
|
|
|
void Cpu::BIT()
|
|
{
|
|
if(CheckFlag(ProcFlags::MemoryMode8)) {
|
|
TestBits<uint8_t>(GetByteValue(), _immediateMode);
|
|
} else {
|
|
TestBits<uint16_t>(GetWordValue(), _immediateMode);
|
|
}
|
|
}
|
|
|
|
void Cpu::TRB()
|
|
{
|
|
if(CheckFlag(ProcFlags::MemoryMode8)) {
|
|
uint8_t value = GetByteValue();
|
|
TestBits<uint8_t>(value, true);
|
|
|
|
value &= ~_state.A;
|
|
Idle();
|
|
|
|
Write(_operand, value);
|
|
} else {
|
|
uint16_t value = GetWordValue();
|
|
TestBits<uint16_t>(value, true);
|
|
|
|
value &= ~_state.A;
|
|
Idle();
|
|
|
|
WriteWord(_operand, value);
|
|
}
|
|
}
|
|
|
|
void Cpu::TSB()
|
|
{
|
|
if(CheckFlag(ProcFlags::MemoryMode8)) {
|
|
uint8_t value = GetByteValue();
|
|
TestBits<uint8_t>(value, true);
|
|
|
|
value |= _state.A;
|
|
Idle();
|
|
|
|
Write(_operand, value);
|
|
} else {
|
|
uint16_t value = GetWordValue();
|
|
TestBits<uint16_t>(value, true);
|
|
|
|
value |= _state.A;
|
|
Idle();
|
|
|
|
WriteWord(_operand, value);
|
|
}
|
|
}
|
|
|
|
/******************
|
|
Transfer operations
|
|
*******************/
|
|
void Cpu::TAX()
|
|
{
|
|
SetRegister(_state.X, _state.A, CheckFlag(ProcFlags::IndexMode8));
|
|
}
|
|
|
|
void Cpu::TAY()
|
|
{
|
|
SetRegister(_state.Y, _state.A, CheckFlag(ProcFlags::IndexMode8));
|
|
}
|
|
|
|
void Cpu::TCD()
|
|
{
|
|
SetRegister(_state.D, _state.A, false);
|
|
}
|
|
|
|
void Cpu::TCS()
|
|
{
|
|
SetSP(_state.A);
|
|
}
|
|
|
|
void Cpu::TDC()
|
|
{
|
|
SetRegister(_state.A, _state.D, false);
|
|
}
|
|
|
|
void Cpu::TSC()
|
|
{
|
|
SetRegister(_state.A, _state.SP, false);
|
|
}
|
|
|
|
void Cpu::TSX()
|
|
{
|
|
SetRegister(_state.X, _state.SP, CheckFlag(ProcFlags::IndexMode8));
|
|
}
|
|
|
|
void Cpu::TXA()
|
|
{
|
|
SetRegister(_state.A, _state.X, CheckFlag(ProcFlags::MemoryMode8));
|
|
}
|
|
|
|
void Cpu::TXS()
|
|
{
|
|
SetSP(_state.X);
|
|
}
|
|
|
|
void Cpu::TXY()
|
|
{
|
|
SetRegister(_state.Y, _state.X, CheckFlag(ProcFlags::IndexMode8));
|
|
}
|
|
|
|
void Cpu::TYA()
|
|
{
|
|
SetRegister(_state.A, _state.Y, CheckFlag(ProcFlags::MemoryMode8));
|
|
}
|
|
|
|
void Cpu::TYX()
|
|
{
|
|
SetRegister(_state.X, _state.Y, CheckFlag(ProcFlags::IndexMode8));
|
|
}
|
|
|
|
void Cpu::XBA()
|
|
{
|
|
Idle();
|
|
_state.A = ((_state.A & 0xFF) << 8) | ((_state.A >> 8) & 0xFF);
|
|
SetZeroNegativeFlags((uint8_t)_state.A);
|
|
}
|
|
|
|
void Cpu::XCE()
|
|
{
|
|
bool carry = CheckFlag(ProcFlags::Carry);
|
|
if(_state.EmulationMode) {
|
|
SetFlags(ProcFlags::Carry);
|
|
} else {
|
|
ClearFlags(ProcFlags::Carry);
|
|
}
|
|
_state.EmulationMode = carry;
|
|
|
|
if(_state.EmulationMode) {
|
|
SetPS(_state.PS | ProcFlags::IndexMode8 | ProcFlags::MemoryMode8);
|
|
_state.SP = 0x100 | (_state.SP & 0xFF);
|
|
}
|
|
}
|
|
|
|
/*****************
|
|
No operation (NOP)
|
|
******************/
|
|
void Cpu::NOP()
|
|
{
|
|
//1-byte NOP
|
|
}
|
|
|
|
void Cpu::WDM()
|
|
{
|
|
//2-byte NOP
|
|
}
|
|
|
|
/****************
|
|
Misc. operations
|
|
*****************/
|
|
void Cpu::STP()
|
|
{
|
|
//Stop the CPU
|
|
_state.StopState = CpuStopState::Stopped;
|
|
}
|
|
|
|
void Cpu::WAI()
|
|
{
|
|
//Wait for interrupt
|
|
_state.StopState = CpuStopState::WaitingForIrq;
|
|
}
|
|
|
|
/****************
|
|
Addressing modes
|
|
*****************/
|
|
void Cpu::AddrMode_Abs()
|
|
{
|
|
_operand = GetDataAddress(ReadOperandWord());
|
|
}
|
|
|
|
void Cpu::AddrMode_AbsIdxX(bool isWrite)
|
|
{
|
|
uint32_t baseAddr = GetDataAddress(ReadOperandWord());
|
|
_operand = (baseAddr + _state.X) & 0xFFFFFF;
|
|
if(isWrite || !CheckFlag(ProcFlags::IndexMode8) || (_operand & 0xFF00) != (baseAddr & 0xFF00)) {
|
|
Idle();
|
|
}
|
|
}
|
|
|
|
void Cpu::AddrMode_AbsIdxY(bool isWrite)
|
|
{
|
|
uint32_t baseAddr = GetDataAddress(ReadOperandWord());
|
|
_operand = (baseAddr + _state.Y) & 0xFFFFFF;
|
|
if(isWrite || !CheckFlag(ProcFlags::IndexMode8) || (_operand & 0xFF00) != (baseAddr & 0xFF00)) {
|
|
Idle();
|
|
}
|
|
}
|
|
|
|
void Cpu::AddrMode_AbsLng()
|
|
{
|
|
_operand = ReadOperandLong();
|
|
}
|
|
|
|
void Cpu::AddrMode_AbsLngIdxX()
|
|
{
|
|
_operand = (ReadOperandLong() + _state.X) & 0xFFFFFF;
|
|
}
|
|
|
|
void Cpu::AddrMode_AbsJmp()
|
|
{
|
|
_operand = GetProgramAddress(ReadOperandWord());
|
|
}
|
|
|
|
void Cpu::AddrMode_AbsLngJmp()
|
|
{
|
|
_operand = ReadOperandLong();
|
|
}
|
|
|
|
void Cpu::AddrMode_AbsIdxXInd()
|
|
{
|
|
_operand = GetProgramAddress(ReadDataWord(GetProgramAddress(ReadOperandWord() + _state.X)));
|
|
Idle();
|
|
}
|
|
|
|
void Cpu::AddrMode_AbsInd()
|
|
{
|
|
_operand = ReadDataWord(ReadOperandWord());
|
|
}
|
|
|
|
void Cpu::AddrMode_AbsIndLng()
|
|
{
|
|
_operand = ReadDataLong(ReadOperandWord());
|
|
}
|
|
|
|
void Cpu::AddrMode_Acc()
|
|
{
|
|
IdleOrRead();
|
|
}
|
|
|
|
void Cpu::AddrMode_BlkMov()
|
|
{
|
|
_operand = ReadOperandWord();
|
|
}
|
|
|
|
uint8_t Cpu::ReadDirectOperandByte()
|
|
{
|
|
uint8_t value = ReadOperandByte();
|
|
if(_state.D & 0xFF) {
|
|
//Add 1 cycle for direct register low (DL) not equal 0
|
|
Idle();
|
|
}
|
|
return value;
|
|
}
|
|
|
|
void Cpu::AddrMode_Dir()
|
|
{
|
|
_operand = GetDirectAddress(ReadDirectOperandByte());
|
|
}
|
|
|
|
void Cpu::AddrMode_DirIdxX()
|
|
{
|
|
_operand = GetDirectAddress(ReadDirectOperandByte() + _state.X);
|
|
Idle();
|
|
}
|
|
|
|
void Cpu::AddrMode_DirIdxY()
|
|
{
|
|
_operand = GetDirectAddress(ReadDirectOperandByte() + _state.Y);
|
|
Idle();
|
|
}
|
|
|
|
void Cpu::AddrMode_DirInd()
|
|
{
|
|
_operand = GetDataAddress(GetDirectAddressIndirectWord(ReadDirectOperandByte()));
|
|
}
|
|
|
|
void Cpu::AddrMode_DirIdxIndX()
|
|
{
|
|
uint8_t operandByte = ReadDirectOperandByte();
|
|
Idle();
|
|
_operand = GetDataAddress(GetDirectAddressIndirectWord(operandByte + _state.X));
|
|
}
|
|
|
|
void Cpu::AddrMode_DirIndIdxY(bool isWrite)
|
|
{
|
|
uint32_t baseAddr = GetDataAddress(GetDirectAddressIndirectWord(ReadDirectOperandByte()));
|
|
_operand = (baseAddr + _state.Y) & 0xFFFFFF;
|
|
|
|
if(isWrite || !CheckFlag(ProcFlags::IndexMode8) || (_operand & 0xFF00) != (baseAddr & 0xFF00)) {
|
|
Idle();
|
|
}
|
|
}
|
|
|
|
void Cpu::AddrMode_DirIndLng()
|
|
{
|
|
_operand = GetDirectAddressIndirectLong(ReadDirectOperandByte());
|
|
}
|
|
|
|
void Cpu::AddrMode_DirIndLngIdxY()
|
|
{
|
|
_operand = (GetDirectAddressIndirectLong(ReadDirectOperandByte()) + _state.Y) & 0xFFFFFF;
|
|
}
|
|
|
|
void Cpu::AddrMode_Imm8()
|
|
{
|
|
_immediateMode = true;
|
|
_operand = ReadOperandByte();
|
|
}
|
|
|
|
void Cpu::AddrMode_Imm16()
|
|
{
|
|
_immediateMode = true;
|
|
_operand = ReadOperandWord();
|
|
}
|
|
|
|
void Cpu::AddrMode_ImmX()
|
|
{
|
|
_immediateMode = true;
|
|
_operand = CheckFlag(ProcFlags::IndexMode8) ? ReadOperandByte() : ReadOperandWord();
|
|
}
|
|
|
|
void Cpu::AddrMode_ImmM()
|
|
{
|
|
_immediateMode = true;
|
|
_operand = CheckFlag(ProcFlags::MemoryMode8) ? ReadOperandByte() : ReadOperandWord();
|
|
}
|
|
|
|
void Cpu::AddrMode_Imp()
|
|
{
|
|
IdleOrRead();
|
|
}
|
|
|
|
void Cpu::AddrMode_RelLng()
|
|
{
|
|
_operand = ReadOperandWord();
|
|
Idle();
|
|
}
|
|
|
|
void Cpu::AddrMode_Rel()
|
|
{
|
|
_operand = ReadOperandByte();
|
|
}
|
|
|
|
void Cpu::AddrMode_StkRel()
|
|
{
|
|
_operand = (uint16_t)(ReadOperandByte() + _state.SP);
|
|
Idle();
|
|
}
|
|
|
|
void Cpu::AddrMode_StkRelIndIdxY()
|
|
{
|
|
uint16_t addr = (uint16_t)(ReadOperandByte() + _state.SP);
|
|
Idle();
|
|
_operand = (GetDataAddress(ReadDataWord(addr)) + _state.Y) & 0xFFFFFF;
|
|
Idle();
|
|
}
|