nes6502.c

PocketNester的c++源代码,很好的学习例子,仅供大家学习

      OPCODE_BEGIN(A7)  /* LAX $nn */
         LAX(3, ZERO_PAGE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(A8)  /* TAY */
         TAY();
         OPCODE_END

      OPCODE_BEGIN(A9)  /* LDA #$nn */
         LDA(2, IMMEDIATE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(AA)  /* TAX */
         TAX();
         OPCODE_END

      OPCODE_BEGIN(AB)  /* LXA #$nn */
         LXA(2, IMMEDIATE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(AC)  /* LDY $nnnn */
         LDY(4, ABSOLUTE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(AD)  /* LDA $nnnn */
         LDA(4, ABSOLUTE_BYTE);
         OPCODE_END
      
      OPCODE_BEGIN(AE)  /* LDX $nnnn */
         LDX(4, ABSOLUTE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(AF)  /* LAX $nnnn */
         LAX(4, ABSOLUTE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(B0)  /* BCS $nnnn */
         BCS();
         OPCODE_END

      OPCODE_BEGIN(B1)  /* LDA ($nn),Y */
         LDA(5, INDIR_Y_BYTE);
         OPCODE_END

      OPCODE_BEGIN(B3)  /* LAX ($nn),Y */
         LAX(5, INDIR_Y_BYTE);
         OPCODE_END

      OPCODE_BEGIN(B4)  /* LDY $nn,X */
         LDY(4, ZP_IND_X_BYTE);
         OPCODE_END

      OPCODE_BEGIN(B5)  /* LDA $nn,X */
         LDA(4, ZP_IND_X_BYTE);
         OPCODE_END

      OPCODE_BEGIN(B6)  /* LDX $nn,Y */
         LDX(4, ZP_IND_Y_BYTE);
         OPCODE_END

      OPCODE_BEGIN(B7)  /* LAX $nn,Y */
         LAX(4, ZP_IND_Y_BYTE);
         OPCODE_END

      OPCODE_BEGIN(B8)  /* CLV */
         CLV();
         OPCODE_END

      OPCODE_BEGIN(B9)  /* LDA $nnnn,Y */
         LDA(4, ABS_IND_Y_BYTE);
         OPCODE_END

      OPCODE_BEGIN(BA)  /* TSX */
         TSX();
         OPCODE_END

      OPCODE_BEGIN(BB)  /* LAS $nnnn,Y */
         LAS(4, ABS_IND_Y_BYTE);
         OPCODE_END

      OPCODE_BEGIN(BC)  /* LDY $nnnn,X */
         LDY(4, ABS_IND_X_BYTE);
         OPCODE_END

      OPCODE_BEGIN(BD)  /* LDA $nnnn,X */
         LDA(4, ABS_IND_X_BYTE);
         OPCODE_END

      OPCODE_BEGIN(BE)  /* LDX $nnnn,Y */
         LDX(4, ABS_IND_Y_BYTE);
         OPCODE_END

      OPCODE_BEGIN(BF)  /* LAX $nnnn,Y */
         LAX(4, ABS_IND_Y_BYTE);
         OPCODE_END

      OPCODE_BEGIN(C0)  /* CPY #$nn */
         CPY(2, IMMEDIATE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(C1)  /* CMP ($nn,X) */
         CMP(6, INDIR_X_BYTE);
         OPCODE_END

      OPCODE_BEGIN(C3)  /* DCP ($nn,X) */
         DCP(8, INDIR_X, mem_writebyte, addr);
         OPCODE_END

      OPCODE_BEGIN(C4)  /* CPY $nn */
         CPY(3, ZERO_PAGE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(C5)  /* CMP $nn */
         CMP(3, ZERO_PAGE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(C6)  /* DEC $nn */
         DEC(5, ZERO_PAGE, ZP_WRITEBYTE, baddr);
         OPCODE_END

      OPCODE_BEGIN(C7)  /* DCP $nn */
         DCP(5, ZERO_PAGE, ZP_WRITEBYTE, baddr);
         OPCODE_END

      OPCODE_BEGIN(C8)  /* INY */
         INY();
         OPCODE_END

      OPCODE_BEGIN(C9)  /* CMP #$nn */
         CMP(2, IMMEDIATE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(CA)  /* DEX */
         DEX();
         OPCODE_END

      OPCODE_BEGIN(CB)  /* SBX #$nn */
         SBX(2, IMMEDIATE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(CC)  /* CPY $nnnn */
         CPY(4, ABSOLUTE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(CD)  /* CMP $nnnn */
         CMP(4, ABSOLUTE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(CE)  /* DEC $nnnn */
         DEC(6, ABSOLUTE, mem_writebyte, addr);
         OPCODE_END

      OPCODE_BEGIN(CF)  /* DCP $nnnn */
         DCP(6, ABSOLUTE, mem_writebyte, addr);
         OPCODE_END
      
      OPCODE_BEGIN(D0)  /* BNE $nnnn */
         BNE();
         OPCODE_END

      OPCODE_BEGIN(D1)  /* CMP ($nn),Y */
         CMP(5, INDIR_Y_BYTE);
         OPCODE_END

      OPCODE_BEGIN(D3)  /* DCP ($nn),Y */
         DCP(8, INDIR_Y, mem_writebyte, addr);
         OPCODE_END

      OPCODE_BEGIN(D5)  /* CMP $nn,X */
         CMP(4, ZP_IND_X_BYTE);
         OPCODE_END

      OPCODE_BEGIN(D6)  /* DEC $nn,X */
         DEC(6, ZP_IND_X, ZP_WRITEBYTE, baddr);
         OPCODE_END

      OPCODE_BEGIN(D7)  /* DCP $nn,X */
         DCP(6, ZP_IND_X, ZP_WRITEBYTE, baddr);
         OPCODE_END

      OPCODE_BEGIN(D8)  /* CLD */
         CLD();
         OPCODE_END

      OPCODE_BEGIN(D9)  /* CMP $nnnn,Y */
         CMP(4, ABS_IND_Y_BYTE);
         OPCODE_END

      OPCODE_BEGIN(DB)  /* DCP $nnnn,Y */
         DCP(7, ABS_IND_Y, mem_writebyte, addr);
         OPCODE_END                  

      OPCODE_BEGIN(DD)  /* CMP $nnnn,X */
         CMP(4, ABS_IND_X_BYTE);
         OPCODE_END

      OPCODE_BEGIN(DE)  /* DEC $nnnn,X */
         DEC(7, ABS_IND_X, mem_writebyte, addr);
         OPCODE_END

      OPCODE_BEGIN(DF)  /* DCP $nnnn,X */
         DCP(7, ABS_IND_X, mem_writebyte, addr);
         OPCODE_END

      OPCODE_BEGIN(E0)  /* CPX #$nn */
         CPX(2, IMMEDIATE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(E1)  /* SBC ($nn,X) */
         SBC(6, INDIR_X_BYTE);
         OPCODE_END

      OPCODE_BEGIN(E3)  /* ISB ($nn,X) */
         ISB(8, INDIR_X, mem_writebyte, addr);
         OPCODE_END

      OPCODE_BEGIN(E4)  /* CPX $nn */
         CPX(3, ZERO_PAGE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(E5)  /* SBC $nn */
         SBC(3, ZERO_PAGE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(E6)  /* INC $nn */
         INC(5, ZERO_PAGE, ZP_WRITEBYTE, baddr);
         OPCODE_END

      OPCODE_BEGIN(E7)  /* ISB $nn */
         ISB(5, ZERO_PAGE, ZP_WRITEBYTE, baddr);
         OPCODE_END

      OPCODE_BEGIN(E8)  /* INX */
         INX();
         OPCODE_END

      OPCODE_BEGIN(E9)  /* SBC #$nn */
      OPCODE_BEGIN(EB)  /* USBC #$nn */
         SBC(2, IMMEDIATE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(EA)  /* NOP */
         NOP();
         OPCODE_END

      OPCODE_BEGIN(EC)  /* CPX $nnnn */
         CPX(4, ABSOLUTE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(ED)  /* SBC $nnnn */
         SBC(4, ABSOLUTE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(EE)  /* INC $nnnn */
         INC(6, ABSOLUTE, mem_writebyte, addr);
         OPCODE_END

      OPCODE_BEGIN(EF)  /* ISB $nnnn */
         ISB(6, ABSOLUTE, mem_writebyte, addr);
         OPCODE_END

      OPCODE_BEGIN(F0)  /* BEQ $nnnn */
         BEQ();
         OPCODE_END

      OPCODE_BEGIN(F1)  /* SBC ($nn),Y */
         SBC(5, INDIR_Y_BYTE);
         OPCODE_END

      OPCODE_BEGIN(F3)  /* ISB ($nn),Y */
         ISB(8, INDIR_Y, mem_writebyte, addr);
         OPCODE_END

      OPCODE_BEGIN(F5)  /* SBC $nn,X */
         SBC(4, ZP_IND_X_BYTE);
         OPCODE_END

      OPCODE_BEGIN(F6)  /* INC $nn,X */
         INC(6, ZP_IND_X, ZP_WRITEBYTE, baddr);
         OPCODE_END

      OPCODE_BEGIN(F7)  /* ISB $nn,X */
         ISB(6, ZP_IND_X, ZP_WRITEBYTE, baddr);
         OPCODE_END

      OPCODE_BEGIN(F8)  /* SED */
         SED();
         OPCODE_END

      OPCODE_BEGIN(F9)  /* SBC $nnnn,Y */
         SBC(4, ABS_IND_Y_BYTE);
         OPCODE_END

      OPCODE_BEGIN(FB)  /* ISB $nnnn,Y */
         ISB(7, ABS_IND_Y, mem_writebyte, addr);
         OPCODE_END

      OPCODE_BEGIN(FD)  /* SBC $nnnn,X */
         SBC(4, ABS_IND_X_BYTE);
         OPCODE_END

      OPCODE_BEGIN(FE)  /* INC $nnnn,X */
         INC(7, ABS_IND_X, mem_writebyte, addr);
         OPCODE_END

      OPCODE_BEGIN(FF)  /* ISB $nnnn,X */
         ISB(7, ABS_IND_X, mem_writebyte, addr);
         OPCODE_END

#ifdef NES6502_JUMPTABLE
end_execute:

#else /* !NES6502_JUMPTABLE */
      }
   }
#endif /* !NES6502_JUMPTABLE */

   /* store local copy of regs */
   STORE_LOCAL_REGS();

   current_PC = 0;

   /* Return our actual amount of executed cycles */
   executed = org_rem_cycles - remaining_cycles;
   cpu.total_cycles += executed;
   return (executed);
}

#else /* OPCODES_BY_FREQUENCY */

static int nes6502_rare_op_execute(int remaining_cycles);

/* Execute instructions until count expires
**
** Returns the number of cycles *actually* executed, which will be
** anywhere from remaining_cycles to remaining_cycles + 6
*/
int nes6502_execute(int remaining_cycles)
{
   //int old_cycles = cpu.total_cycles;
   int org_rem_cycles = remaining_cycles;
   int executed;

#if 1
   uint32 temp, addr; /* for macros */
   uint8 btemp, baddr; /* for macros */
   uint8 data;
#endif

   /* flags */
   //uint8 n_flag, v_flag, b_flag;
   //uint8 d_flag, i_flag, z_flag, c_flag;
   uint32 n_flag, v_flag, b_flag;
   uint32 i_flag, z_flag, c_flag;

   /* local copies of regs */
   uint32 PC;
   uint8 * last_bank_ptr;
   //uint8 A, X, Y, S;
   uint8 X, Y;
   uint32 A, S;

#undef ram
#undef stack
   uint8*	ram_l   = ram;
   uint8*	stack_l = stack;
   uint8**  mem_page = cpu.mem_page;
   uint8 (*read_func)(uint32 address) = cpu.read_handler->read_func;
   void (*write_func)(uint32 address, uint8 value) = cpu.write_handler->write_func;
#define ram		ram_l
#define stack	stack_l

#define  OPCODE_BEGIN_NO_VARS(xx)  case 0x##xx:
#define  OPCODE_BEGIN(xx)	\
	case 0x##xx: \
	{	\
		/*uint32 temp, addr; /* for macros */	\
		/*uint8 btemp, baddr; /* for macros */\
		/*uint8 data;*/

/* #define  OPCODE_END        break; */
#define  OPCODE_END        \
	} \
	goto next_opcode;

   GET_GLOBAL_REGS();

   if (cpu.int_pending && remaining_cycles)
   {
      if (0 == i_flag)
      {
         cpu.int_pending = 0;
         IRQ();
      }
   }

   /* check for DMA cycle burning */
   if (cpu.burn_cycles && remaining_cycles)
   {
      int burn_for;
      
      burn_for = MIN(remaining_cycles, cpu.burn_cycles);
      ADD_CYCLES(burn_for);
      cpu.burn_cycles -= burn_for;
   }

   current_PC = &PC;
   current_last_bank_ptr = &last_bank_ptr;

next_opcode:
   /* Continue until we run out of cycles */
   while (remaining_cycles > 0)
   {
#ifdef NES6502_DISASM
      log_printf(nes6502_disasm(PC, COMBINE_FLAGS(), A, X, Y, S));
#endif /* NES6502_DISASM */

      /* Fetch and execute instruction */
      //switch (bank_readbyte(PC++))
	  /* uint8 c = bank_readbyte(PC);
	  PC++;
	  */
#pragma warning ( disable : 4101 )
	  switch (*(uint8 *)PC++)
      {

      OPCODE_BEGIN(A5)  /* LDA $nn */
         LDA(3, ZERO_PAGE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(4C)  /* JMP $nnnn */
         JMP_ABSOLUTE();
         OPCODE_END

      OPCODE_BEGIN(F0)  /* BEQ $nnnn */
         BEQ();
         OPCODE_END

      OPCODE_BEGIN(D0)  /* BNE $nnnn */
         BNE();
         OPCODE_END

      OPCODE_BEGIN(85)  /* STA $nn */
         STA(3, ZERO_PAGE_ADDR, ZP_WRITEBYTE, baddr);
         OPCODE_END

      OPCODE_BEGIN(C9)  /* CMP #$nn */
         CMP(2, IMMEDIATE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(BD)  /* LDA $nnnn,X */
         LDA(4, ABS_IND_X_BYTE);
         OPCODE_END

      OPCODE_BEGIN(18)  /* CLC */
         CLC();
         OPCODE_END

      OPCODE_BEGIN(65)  /* ADC $nn */
         ADC(3, ZERO_PAGE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(9D)  /* STA $nnnn,X */
         STA(5, ABS_IND_X_ADDR, mem_writebyte, addr);
         OPCODE_END

      OPCODE_BEGIN(C8)  /* INY */
         INY();
         OPCODE_END

      OPCODE_BEGIN(E6)  /* INC $nn */
         INC(5, ZERO_PAGE, ZP_WRITEBYTE, baddr);
         OPCODE_END

      OPCODE_BEGIN(8D)  /* STA $nnnn */
         STA(4, ABSOLUTE_ADDR, mem_writebyte, addr);
         OPCODE_END

      OPCODE_BEGIN(E8)  /* INX */
         INX();
         OPCODE_END

      OPCODE_BEGIN(29)  /* AND #$nn */
         AND(2, IMMEDIATE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(20)  /* JSR $nnnn */
         JSR();
         OPCODE_END

      OPCODE_BEGIN(60)  /* RTS */
         RTS();
         OPCODE_END

      OPCODE_BEGIN(A9)  /* LDA #$nn */
         LDA(2, IMMEDIATE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(30)  /* BMI $nnnn */
         BMI();
         OPCODE_END

      OPCODE_BEGIN(AD)  /* LDA $nnnn */
         LDA(4, ABSOLUTE_BYTE);
         OPCODE_END
      
      OPCODE_BEGIN(4A)  /* LSR A */
         LSR_A();
         OPCODE_END

      OPCODE_BEGIN(B1)  /* LDA ($nn),Y */
         LDA(5, INDIR_Y_BYTE);
         OPCODE_END

      OPCODE_BEGIN(88)  /* DEY */
         DEY();
         OPCODE_END

      OPCODE_BEGIN(69)  /* ADC #$nn */
         ADC(2, IMMEDIATE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(90)  /* BCC $nnnn */
         BCC();
         OPCODE_END

      OPCODE_BEGIN(10)  /* BPL $nnnn */
         BPL();
         OPCODE_END

      OPCODE_BEGIN(B9)  /* LDA $nnnn,Y */
         LDA(4, ABS_IND_Y_BYTE);
         OPCODE_END

      OPCODE_BEGIN(AA)  /* TAX */
         TAX();
         OPCODE_END

      OPCODE_BEGIN(0A)  /* ASL A */
         ASL_A();
         OPCODE_END

      OPCODE_BEGIN(CA)  /* DEX */
         DEX();
         OPCODE_END

      OPCODE_BEGIN(B0)  /* BCS $nnnn */
         BCS();
         OPCODE_END

      OPCODE_BEGIN(38)  /* SEC */
         SEC();
         OPCODE_END

      OPCODE_BEGIN(A0)  /* LDY #$nn */
         LDY(2, IMMEDIATE_BYTE);
         OPCODE_END

      OPCODE_BEGIN(C6)  /* DEC $nn */
         DEC(5, ZERO_PAGE, ZP_WRITEBYTE, baddr);
         OPCODE_END

      OPCODE_BEGIN(2C)  /* BIT $nnnn */
         BIT(4, ABSOLUTE_BYTE);