105 lines
6.3 KiB
C++
105 lines
6.3 KiB
C++
#include "stdafx.h"
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#include "CPU.h"
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#include "Timer.h"
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uint64_t CPU::CycleCount = 0;
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bool CPU::NMIFlag = false;
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CPU::CPU(MemoryManager *memoryManager) : _memoryManager(memoryManager)
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{
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Func opTable[] = {
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// 0 1 2 3 4 5 6 7 8 9 A B C D E F
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&CPU::BRK, &CPU::ORA_IndX, nullptr, nullptr, nullptr, &CPU::ORA_Zero, &CPU::ASL_Zero, nullptr, &CPU::PHP, &CPU::ORA_Imm, &CPU::ASL_Acc, nullptr, nullptr, &CPU::ORA_Abs, &CPU::ASL_Abs, nullptr, //0
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&CPU::BPL, &CPU::ORA_IndY, nullptr, nullptr, nullptr, &CPU::ORA_ZeroX, &CPU::ASL_ZeroX, nullptr, &CPU::CLC, &CPU::ORA_AbsY, nullptr, nullptr, nullptr, &CPU::ORA_AbsX, &CPU::ASL_AbsX, nullptr, //1
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&CPU::JSR, &CPU::AND_IndX, nullptr, nullptr, &CPU::BIT_Zero, &CPU::AND_Zero, &CPU::ROL_Zero, nullptr, &CPU::PLP, &CPU::AND_Imm, &CPU::ROL_Acc, nullptr, &CPU::BIT_Abs, &CPU::AND_Abs, &CPU::ROL_Abs, nullptr, //2
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&CPU::BMI, &CPU::AND_IndY, nullptr, nullptr, nullptr, &CPU::AND_ZeroX, &CPU::ROL_ZeroX, nullptr, &CPU::SEC, &CPU::AND_AbsY, nullptr, nullptr, nullptr, &CPU::AND_AbsX, &CPU::ROL_AbsX, nullptr, //3
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&CPU::RTI, &CPU::EOR_IndX, nullptr, nullptr, nullptr, &CPU::EOR_Zero, &CPU::LSR_Zero, nullptr, &CPU::PHA, &CPU::EOR_Imm, &CPU::LSR_Acc, nullptr, &CPU::JMP_Abs, &CPU::EOR_Abs, &CPU::LSR_Abs, nullptr, //4
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&CPU::BVC, &CPU::EOR_IndY, nullptr, nullptr, nullptr, &CPU::EOR_ZeroX, &CPU::LSR_ZeroX, nullptr, &CPU::CLI, &CPU::EOR_AbsY, nullptr, nullptr, nullptr, &CPU::EOR_AbsX, &CPU::LSR_AbsX, nullptr, //5
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&CPU::RTS, &CPU::ADC_IndX, nullptr, nullptr, nullptr, &CPU::ADC_Zero, &CPU::ROR_Zero, nullptr, &CPU::PLA, &CPU::ADC_Imm, &CPU::ROR_Acc, nullptr, &CPU::JMP_Ind, &CPU::ADC_Abs, &CPU::ROR_Abs, nullptr, //6
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&CPU::BVS, &CPU::ADC_IndY, nullptr, nullptr, nullptr, &CPU::ADC_ZeroX, &CPU::ROR_ZeroX, nullptr, &CPU::SEI, &CPU::ADC_AbsY, nullptr, nullptr, nullptr, &CPU::ADC_AbsX, &CPU::ROR_AbsX, nullptr, //7
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nullptr, &CPU::STA_IndX, nullptr, nullptr, &CPU::STY_Zero, &CPU::STA_Zero, &CPU::STX_Zero, nullptr, &CPU::DEY, nullptr, &CPU::TXA, nullptr, &CPU::STY_Abs, &CPU::STA_Abs, &CPU::STX_Abs, nullptr, //8
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&CPU::BCC, &CPU::STA_IndY, nullptr, nullptr, &CPU::STY_ZeroX, &CPU::STA_ZeroX, &CPU::STX_ZeroY, nullptr, &CPU::TYA, &CPU::STA_AbsY, &CPU::TXS, nullptr, nullptr, &CPU::STA_AbsX, nullptr, nullptr, //9
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&CPU::LDY_Imm, &CPU::LDA_IndX, &CPU::LDX_Imm, nullptr, &CPU::LDY_Zero, &CPU::LDA_Zero, &CPU::LDX_Zero, nullptr, &CPU::TAY, &CPU::LDA_Imm, &CPU::TAX, nullptr, &CPU::LDY_Abs, &CPU::LDA_Abs, &CPU::LDX_Abs, nullptr, //A
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&CPU::BCS, &CPU::LDA_IndY, nullptr, nullptr, &CPU::LDY_ZeroX, &CPU::LDA_ZeroX, &CPU::LDX_ZeroY, nullptr, &CPU::CLV, &CPU::LDA_AbsY, &CPU::TSX, nullptr, &CPU::LDY_AbsX, &CPU::LDA_AbsX, &CPU::LDX_AbsY, nullptr, //B
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&CPU::CPY_Imm, &CPU::CMP_IndX, nullptr, nullptr, &CPU::CPY_Zero, &CPU::CMP_Zero, &CPU::DEC_Zero, nullptr, &CPU::INY, &CPU::CMP_Imm, &CPU::DEX, nullptr, &CPU::CPY_Abs, &CPU::CMP_Abs, &CPU::DEC_Abs, nullptr, //C
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&CPU::BNE, &CPU::CMP_IndY, nullptr, nullptr, nullptr, &CPU::CMP_ZeroX, &CPU::DEC_ZeroX, nullptr, &CPU::CLD, &CPU::CMP_AbsY, nullptr, nullptr, nullptr, &CPU::CMP_AbsX, &CPU::DEC_AbsX, nullptr, //D
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&CPU::CPX_Imm, &CPU::SBC_IndX, nullptr, nullptr, &CPU::CPX_Zero, &CPU::SBC_Zero, &CPU::INC_Zero, nullptr, &CPU::INX, &CPU::SBC_Imm, &CPU::NOP, nullptr, &CPU::CPX_Abs, &CPU::SBC_Abs, &CPU::INC_Abs, nullptr, //E
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&CPU::BEQ, &CPU::SBC_IndY, nullptr, nullptr, nullptr, &CPU::SBC_ZeroX, &CPU::INC_ZeroX, nullptr, &CPU::SED, &CPU::SBC_AbsY, nullptr, nullptr, nullptr, &CPU::SBC_AbsX, &CPU::INC_AbsX, nullptr //F
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};
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uint8_t cycles[] {
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7, 6, 2, 8, 3, 3, 5, 5, 3, 2, 2, 2, 4, 4, 6, 6,
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2, 5, 2, 8, 4, 4, 6, 6, 2, 4, 2, 7, 4, 4, 7, 7,
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6, 6, 2, 8, 3, 3, 5, 5, 4, 2, 2, 2, 4, 4, 6, 6,
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2, 5, 2, 8, 4, 4, 6, 6, 2, 4, 2, 7, 4, 4, 7, 7,
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6, 6, 2, 8, 3, 3, 5, 5, 3, 2, 2, 2, 3, 4, 6, 6,
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2, 5, 2, 8, 4, 4, 6, 6, 2, 4, 2, 7, 4, 4, 7, 7,
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6, 6, 2, 8, 3, 3, 5, 5, 4, 2, 2, 2, 5, 4, 6, 6,
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2, 5, 2, 8, 4, 4, 6, 6, 2, 4, 2, 7, 4, 4, 7, 7,
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2, 6, 2, 6, 3, 3, 3, 3, 2, 2, 2, 2, 4, 4, 4, 4,
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2, 6, 2, 6, 4, 4, 4, 4, 2, 5, 2, 5, 5, 5, 5, 5,
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2, 6, 2, 6, 3, 3, 3, 3, 2, 2, 2, 2, 4, 4, 4, 4,
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2, 5, 2, 5, 4, 4, 4, 4, 2, 4, 2, 4, 4, 4, 4, 4,
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2, 6, 2, 8, 3, 3, 5, 5, 2, 2, 2, 2, 4, 4, 6, 6,
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2, 5, 2, 8, 4, 4, 6, 6, 2, 4, 2, 7, 4, 4, 7, 7,
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2, 6, 3, 8, 3, 3, 5, 5, 2, 2, 2, 2, 4, 4, 6, 6,
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2, 5, 2, 8, 4, 4, 6, 6, 2, 4, 2, 7, 4, 4, 7, 7,
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};
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uint8_t cyclesPageCrossed[] {
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7, 6, 2, 8, 3, 3, 5, 5, 3, 2, 2, 2, 4, 4, 6, 6,
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2, 6, 2, 8, 4, 4, 6, 6, 2, 5, 2, 7, 5, 5, 7, 7,
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6, 6, 2, 8, 3, 3, 5, 5, 4, 2, 2, 2, 4, 4, 6, 6,
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2, 6, 2, 8, 4, 4, 6, 6, 2, 5, 2, 7, 5, 5, 7, 7,
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6, 6, 2, 8, 3, 3, 5, 5, 3, 2, 2, 2, 3, 4, 6, 6,
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2, 6, 2, 8, 4, 4, 6, 6, 2, 5, 2, 7, 5, 5, 7, 7,
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6, 6, 2, 8, 3, 3, 5, 5, 4, 2, 2, 2, 5, 4, 6, 6,
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2, 6, 2, 8, 4, 4, 6, 6, 2, 5, 2, 7, 5, 5, 7, 7,
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2, 6, 2, 6, 3, 3, 3, 3, 2, 2, 2, 2, 4, 4, 4, 4,
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2, 6, 2, 6, 4, 4, 4, 4, 2, 5, 2, 5, 5, 5, 5, 5,
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2, 6, 2, 6, 3, 3, 3, 3, 2, 2, 2, 2, 4, 4, 4, 4,
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2, 6, 2, 5, 4, 4, 4, 4, 2, 5, 2, 5, 5, 5, 5, 5,
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2, 6, 2, 8, 3, 3, 5, 5, 2, 2, 2, 2, 4, 4, 6, 6,
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2, 6, 2, 8, 4, 4, 6, 6, 2, 5, 2, 7, 5, 5, 7, 7,
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2, 6, 3, 8, 3, 3, 5, 5, 2, 2, 2, 2, 4, 4, 6, 6,
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2, 6, 2, 8, 4, 4, 6, 6, 2, 5, 2, 7, 5, 5, 7, 7,
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};
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memcpy(_opTable, opTable, sizeof(Func) * 256);
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memcpy(_cycles, cycles, sizeof(uint8_t) * 256);
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memcpy(_cyclesPageCrossed, cyclesPageCrossed, sizeof(uint8_t) * 256);
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}
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void CPU::Reset()
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{
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CPU::CycleCount = 0;
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_state.A = 0;
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_state.PC = MemoryReadWord(0xFFFC);
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_state.SP = 0xFF;
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_state.X = 0;
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_state.Y = 0;
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_state.PS = PSFlags::Zero | PSFlags::Reserved;// | PSFlags::Interrupt;
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}
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void CPU::Exec()
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{
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if(!_runNMI) {
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if(CPU::NMIFlag) {
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_runNMI = true;
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}
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uint8_t opCode = ReadByte();
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if(_opTable[opCode] != nullptr) {
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(this->*_opTable[opCode])();
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CPU::CycleCount += GetPageCrossed() ? this->_cyclesPageCrossed[opCode] : this->_cycles[opCode];
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} else {
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//std::cout << "Invalid opcode: " << std::hex << (short)opCode;
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//throw exception("Invalid opcode");
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}
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} else {
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NMI();
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CPU::CycleCount += 7;
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_runNMI = false;
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CPU::NMIFlag = false;
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}
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}
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