78 lines
1.2 KiB
C
78 lines
1.2 KiB
C
#ifndef _CPU_H_
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#define _CPU_H_
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#include "types.h"
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struct Bus;
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typedef enum
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{
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XXX = 0,
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ADC, AND, ASL, BCC, BCS, BEQ, BIT, BMI,
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BNE, BPL, BRK, BVC, BVS, CLC, CLD, CLI,
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CLV, CMP, CPX, CPY, DEC, DEX, DEY, EOR,
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INC, INX, INY, JMP, JSR, LDA, LDX, LDY,
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LSR, NOP, ORA, PHA, PHP, PLA, PLP, ROL,
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ROR, RTI, RTS, SBC, SEC, SED, SEI, STA,
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STX, STY, TAX, TAY, TSX, TXA, TXS, TYA
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} Operation;
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typedef enum
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{
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ACC, ABS, ABX, ABY, IMM, IMP, IND, XIN, INY, REL, ZPG, ZPX, ZPY
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} AddrMode;
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struct Opcode
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{
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Operation op;
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AddrMode addr;
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Byte cycles;
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const char str[4];
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};
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const struct Opcode OPCODE_MATRIX[512];
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struct CPU
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{
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Byte acc;
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Byte x, y;
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Byte sp;
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union
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{
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struct
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{
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Byte carry : 1;
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Byte zero : 1;
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Byte id : 1;
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Byte decimal : 1;
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Byte unused : 2;
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Byte overflow : 1;
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Byte negative : 1;
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};
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Byte raw;
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} status;
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Word pc;
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Byte remainingCycles;
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Byte fetchedVal;
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Word fetchedAddress;
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const struct Opcode* currentOpcode;
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struct Bus* bus;
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};
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struct CPU* createCPU(struct Bus* parent);
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void destroyCPU(struct CPU* cpu);
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void tickCPU(struct CPU* cpu);
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void tickInstr(struct CPU* cpu);
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void fetch(struct CPU* cpu);
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void execute(struct CPU* cpu);
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#endif // _CPU_H_
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