kopia lustrzana https://github.com/Jean-MarcHarvengt/MCUME
192 wiersze
5.0 KiB
C++
192 wiersze
5.0 KiB
C++
#ifndef _H_MOS6502
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#define _H_MOS6502
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//============================================================================
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// Name : mos6502
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// Author : Gianluca Ghettini
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// Version : 1.0
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// Copyright :
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// Description : A MOS 6502 CPU emulator written in C++
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//============================================================================
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#include <stdint.h>
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#define NEGATIVE 0x80
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#define OVERFLOW 0x40
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#define CONSTANT 0x20
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#define BREAK 0x10
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#define DECIMAL 0x08
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#define INTERRUPT 0x04
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#define ZERO 0x02
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#define CARRY 0x01
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#define SET_NEGATIVE(x) (x ? (status |= NEGATIVE) : (status &= (~NEGATIVE)) )
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#define SET_OVERFLOW(x) (x ? (status |= OVERFLOW) : (status &= (~OVERFLOW)) )
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#define SET_CONSTANT(x) (x ? (status |= CONSTANT) : (status &= (~CONSTANT)) )
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#define SET_BREAK(x) (x ? (status |= BREAK) : (status &= (~BREAK)) )
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#define SET_DECIMAL(x) (x ? (status |= DECIMAL) : (status &= (~DECIMAL)) )
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#define SET_INTERRUPT(x) (x ? (status |= INTERRUPT) : (status &= (~INTERRUPT)) )
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#define SET_ZERO(x) (x ? (status |= ZERO) : (status &= (~ZERO)) )
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#define SET_CARRY(x) (x ? (status |= CARRY) : (status &= (~CARRY)) )
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#define IF_NEGATIVE() ((status & NEGATIVE) ? true : false)
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#define IF_OVERFLOW() ((status & OVERFLOW) ? true : false)
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#define IF_CONSTANT() ((status & CONSTANT) ? true : false)
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#define IF_BREAK() ((status & BREAK) ? true : false)
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#define IF_DECIMAL() ((status & DECIMAL) ? true : false)
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#define IF_INTERRUPT() ((status & INTERRUPT) ? true : false)
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#define IF_ZERO() ((status & ZERO) ? true : false)
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#define IF_CARRY() ((status & CARRY) ? true : false)
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class mos6502
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{
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private:
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// registers
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uint8_t A; // accumulator
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uint8_t X; // X-index
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uint8_t Y; // Y-index
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// stack pointer
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uint8_t sp;
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// program counter
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uint16_t pc;
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// status register
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uint8_t status;
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typedef void (mos6502::*CodeExec)(uint16_t);
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typedef uint16_t (mos6502::*AddrExec)();
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struct Instr
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{
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AddrExec addr;
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CodeExec code;
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uint8_t cycles;
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};
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Instr InstrTable[256];
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void Exec(Instr i);
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bool illegalOpcode;
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// addressing modes
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uint16_t Addr_ACC(); // ACCUMULATOR
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uint16_t Addr_IMM(); // IMMEDIATE
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uint16_t Addr_ABS(); // ABSOLUTE
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uint16_t Addr_ZER(); // ZERO PAGE
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uint16_t Addr_ZEX(); // INDEXED-X ZERO PAGE
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uint16_t Addr_ZEY(); // INDEXED-Y ZERO PAGE
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uint16_t Addr_ABX(); // INDEXED-X ABSOLUTE
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uint16_t Addr_ABY(); // INDEXED-Y ABSOLUTE
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uint16_t Addr_IMP(); // IMPLIED
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uint16_t Addr_REL(); // RELATIVE
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uint16_t Addr_INX(); // INDEXED-X INDIRECT
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uint16_t Addr_INY(); // INDEXED-Y INDIRECT
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uint16_t Addr_ABI(); // ABSOLUTE INDIRECT
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// opcodes (grouped as per datasheet)
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void Op_ADC(uint16_t src);
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void Op_AND(uint16_t src);
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void Op_ASL(uint16_t src); void Op_ASL_ACC(uint16_t src);
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void Op_BCC(uint16_t src);
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void Op_BCS(uint16_t src);
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void Op_BEQ(uint16_t src);
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void Op_BIT(uint16_t src);
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void Op_BMI(uint16_t src);
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void Op_BNE(uint16_t src);
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void Op_BPL(uint16_t src);
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void Op_BRK(uint16_t src);
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void Op_BVC(uint16_t src);
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void Op_BVS(uint16_t src);
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void Op_CLC(uint16_t src);
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void Op_CLD(uint16_t src);
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void Op_CLI(uint16_t src);
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void Op_CLV(uint16_t src);
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void Op_CMP(uint16_t src);
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void Op_CPX(uint16_t src);
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void Op_CPY(uint16_t src);
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void Op_DEC(uint16_t src);
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void Op_DEX(uint16_t src);
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void Op_DEY(uint16_t src);
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void Op_EOR(uint16_t src);
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void Op_INC(uint16_t src);
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void Op_INX(uint16_t src);
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void Op_INY(uint16_t src);
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void Op_JMP(uint16_t src);
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void Op_JSR(uint16_t src);
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void Op_LDA(uint16_t src);
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void Op_LDX(uint16_t src);
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void Op_LDY(uint16_t src);
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void Op_LSR(uint16_t src); void Op_LSR_ACC(uint16_t src);
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void Op_NOP(uint16_t src);
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void Op_ORA(uint16_t src);
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void Op_PHA(uint16_t src);
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void Op_PHP(uint16_t src);
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void Op_PLA(uint16_t src);
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void Op_PLP(uint16_t src);
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void Op_ROL(uint16_t src); void Op_ROL_ACC(uint16_t src);
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void Op_ROR(uint16_t src); void Op_ROR_ACC(uint16_t src);
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void Op_RTI(uint16_t src);
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void Op_RTS(uint16_t src);
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void Op_SBC(uint16_t src);
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void Op_SEC(uint16_t src);
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void Op_SED(uint16_t src);
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void Op_SEI(uint16_t src);
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void Op_STA(uint16_t src);
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void Op_STX(uint16_t src);
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void Op_STY(uint16_t src);
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void Op_TAX(uint16_t src);
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void Op_TAY(uint16_t src);
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void Op_TSX(uint16_t src);
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void Op_TXA(uint16_t src);
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void Op_TXS(uint16_t src);
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void Op_TYA(uint16_t src);
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void Op_ILLEGAL(uint16_t src);
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// IRQ, reset, NMI vectors
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static const uint16_t irqVectorH = 0xFFFF;
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static const uint16_t irqVectorL = 0xFFFE;
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static const uint16_t rstVectorH = 0xFFFD;
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static const uint16_t rstVectorL = 0xFFFC;
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static const uint16_t nmiVectorH = 0xFFFB;
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static const uint16_t nmiVectorL = 0xFFFA;
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// read/write callbacks
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//typedef void (*BusWrite)(uint16_t, uint8_t);
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//typedef uint8_t (*BusRead)(uint16_t);
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//BusRead Read;
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//BusWrite Write;
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// stack operations
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inline void StackPush(uint8_t byte);
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inline uint8_t StackPop();
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public:
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enum CycleMethod {
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INST_COUNT,
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CYCLE_COUNT,
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};
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mos6502();
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void NMI();
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int IRQ();
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void Reset();
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uint64_t Run(
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int32_t cycles,
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CycleMethod cycleMethod = CYCLE_COUNT);
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};
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#endif |