cpu.pas

delphi编制的nes模拟器－－tNes

            end;

  //*                                       *
  //*       dec instruction 2005/12/27      *
  //*---------------end---------------------*


  //*                                       *
  //*       dex instruction 2005/12/27      *
  //*---------------start-------------------*
        $CA: //
            begin
{$IFDEF debug}
                curIns := 'DEX ';
{$ENDIF}

                tempbyte := x;
                asm
					dec tempbyte
                end;
                x := tempbyte;
                setnz(tempbyte);

                inc(cycles, 2);
                inc(pc);

            end;

  //*                                       *
  //*       dex instruction 2005/12/27      *
  //*---------------end---------------------*


  //*                                       *
  //*       dey instruction 2005/12/27      *
  //*---------------start-------------------*
        $88: //
            begin
{$IFDEF debug}
                curIns := 'DEY ';
{$ENDIF}

                tempbyte := y;
                asm
         			dec tempbyte
                end;
				y := tempbyte;
				
                setnz(tempbyte);

                inc(cycles, 2);
                inc(pc);

            end;

  //*                                       *
  //*       dey instruction 2005/12/27      *
  //*---------------end---------------------*



  //*                                       *
  //*       eor instruction 2005/12/29      *
  //*---------------start-------------------*
        $49: //immediate
            begin
{$IFDEF debug}
                curIns := 'EOR #$' + intToHex(memread(pc + 1), 0);
{$ENDIF}

                tempbyte := memread(pc + 1);
                a := tempbyte xor a;
                setnz(a);

                inc(cycles, 2);
                inc(pc, 2);
            end;

  //*                                       *
  //*       eor instruction 2005/12/29      *
  //*---------------end---------------------*

  //*                                       *
  //*       eor instruction 2005/12/29      *
  //*---------------start-------------------*
        $45: //zero
			begin
				taddr:=ZpAddress(pc);
				tempbyte:=memread(taddr);
{$IFDEF debug}
                curIns := 'EOR $' + intToHex(taddr, 0);
{$ENDIF}

                a := tempbyte xor a;
                setnz(a);

                inc(cycles, 3);
                inc(pc, 2);
            end;

  //*                                       *
  //*       eor instruction 2005/12/29      *
  //*---------------end---------------------*

  //*                                       *
  //*       eor instruction 2005/12/29      *
  //*---------------start-------------------*
        $55: //zero,x
			begin
				taddr:=IzpAddress(pc,x);
				tempbyte:=memread(taddr);
{$IFDEF debug}
				curIns := 'EOR $' + intToHex(memread(pc + 1), 0) + ',X ';
{$ENDIF}

				a := tempbyte xor a;
                setnz(a);

                inc(cycles, 4);
				inc(pc, 2);
            end;

  //*                                       *
  //*       eor instruction 2005/12/29      *
  //*---------------end---------------------*


  //*                                       *
  //*       eor instruction 2005/12/29      *
  //*---------------start-------------------*
        $4D: //absolute
            begin


				taddr:=AbAddress(pc);
				tempbyte:=memread(taddr);
{$IFDEF debug}
                curIns := 'EOR $' + intToHex(taddr, 0);
{$ENDIF}
                a := tempbyte xor a;
                setnz(a);

                inc(cycles, 4);
                inc(pc, 3);
            end;

  //*                                       *
  //*       eor instruction 2005/12/29      *
  //*---------------end---------------------*


  //*                                       *
  //*       eor instruction 2005/12/29      *
  //*---------------start-------------------*
        $5D: //absolute,x
            begin


				taddr:=iabaddress(pc,x);
				tempbyte:=memread(taddr);
{$IFDEF debug}
				curIns := 'EOR $' + intToHex(taddr-x, 0) + ',X';
{$ENDIF}
                a := tempbyte xor a;
                setnz(a);

                inc(cycles, 4);
				inc(pc, 3);
            end;

  //*                                       *
  //*       eor instruction 2005/12/29      *
  //*---------------end---------------------*

  //*                                       *
  //*       eor instruction 2005/12/29      *
  //*---------------start-------------------*
        $59: //absolute,y
            begin


				taddr:=iabaddress(pc,y);
				tempbyte:=memread(taddr);
{$IFDEF debug}
                curIns := 'EOR $' + intToHex(taddr-y, 0) + ',Y';
{$ENDIF}
                a := tempbyte xor a;
                setnz(a);

                inc(cycles, 4);
                inc(pc, 3);
            end;

  //*                                       *
  //*       eor instruction 2005/12/29      *
  //*---------------end---------------------*

  //*                                       *
  //*       eor instruction 2005/12/29      *
  //*---------------start-------------------*
		$41: //indirect,x
            begin
{$IFDEF debug}
                curIns := 'EOR ($' + intToHex(memread(pc + 1), 0) + ',X) ';
{$ENDIF}


				taddr:=iixaddress(pc,x);
				tempbyte:=memread(taddr);
				
                a := tempbyte xor a;
                setnz(a);


                inc(cycles, 6);
                inc(pc, 2);
            end;

  //*                                       *
  //*       eor instruction 2005/12/29      *
  //*---------------end---------------------*

  //*                                       *
  //*       eor instruction 2005/12/29      *
  //*---------------start-------------------*
		$51: //(indirect),y
            begin
{$IFDEF debug}
                curIns := 'EOR ($' + intToHex(memread(pc + 1), 0) + '),Y ';
{$ENDIF}

				taddr:=iiyaddress(pc,y);
				tempbyte:=memread(taddr);

                a := tempbyte xor a;
                setnz(a);

                inc(cycles, 5);
                inc(pc, 2);
            end;

  //*                                       *
  //*       eor instruction 2005/12/29      *
  //*---------------end---------------------*

  //*                                       *
  //*       inc instruction 2005/12/29      *
  //*---------------start-------------------*
        $E6: //zero page
			begin
				taddr:=zpaddress(pc);
				tempbyte:=memread(taddr);
{$IFDEF debug}
				curIns := 'INC $' + intToHex(taddr, 0);
{$ENDIF}

				asm
         			inc tempbyte
                end;
				memwrite(taddr, tempbyte);
                setnz(tempbyte);

                inc(cycles, 5);
                inc(pc, 2);

            end;

  //*                                       *
  //*       inc instruction 2005/12/29      *
  //*---------------end---------------------*


  //*                                       *
  //*       inc instruction 2005/12/29      *
  //*---------------start-------------------*
		$F6: //zero page,x
			begin
				taddr:=izpaddress(pc,x);
				tempbyte:=memread(taddr);
{$IFDEF debug}
                curIns := 'INC $' + intToHex(memread(pc + 1), 0) + ',X ';
{$ENDIF}

				asm
					inc tempbyte
                end;
				memwrite(taddr, tempbyte);
                setnz(tempbyte);

                inc(cycles, 6);
                inc(pc, 2);

            end;

  //*                                       *
  //*       inc instruction 2005/12/29      *
  //*---------------end---------------------*


  //*                                       *
  //*       inc instruction 2005/12/29      *
  //*---------------start-------------------*
        $EE: //absolute
            begin

				taddr:=abaddress(pc);
				tempbyte:=memread(taddr);

{$IFDEF debug}
                curIns := 'INC $' + intToHex(taddr, 0);
{$ENDIF}
                asm
					inc tempbyte
                end;
                memwrite(taddr, tempbyte);
                setnz(tempbyte);

                inc(cycles, 6);
                inc(pc, 3);

            end;

  //*                                       *
  //*       inc instruction 2005/12/29      *
  //*---------------end---------------------*


  //*                                       *
  //*       inc instruction 2005/12/29      *
  //*---------------start-------------------*
        $FE: //absolute,x
            begin
				taddr:=iabaddress(pc,x);
				tempbyte:=memread(taddr);
{$IFDEF debug}
                curIns := 'INC $' + intToHex(taddr, 0) + ',X';
{$ENDIF}
                asm
					inc tempbyte
                end;
                memwrite(taddr, tempbyte);
                setnz(tempbyte);

                inc(cycles, 7);
                inc(pc, 3);

            end;

  //*                                       *
  //*       inc instruction 2005/12/29      *
  //*---------------end---------------------*


  //*                                       *
  //*       inx instruction 2005/12/29      *
  //*---------------start-------------------*
        $E8: //
            begin
{$IFDEF debug}
                curIns := 'INX ';
{$ENDIF}

                tempbyte := x;
                asm
         			inc tempbyte
                end;
                x := tempbyte;
                setnz(tempbyte);

                inc(cycles, 2);
                inc(pc);

            end;

  //*                                       *
  //*       inx instruction 2005/12/29      *
  //*---------------end---------------------*


  //*                                       *
  //*       iny instruction 2005/12/29      *
  //*---------------start-------------------*
        $C8: //
            begin
{$IFDEF debug}
                curIns := 'INY ';
{$ENDIF}

                tempbyte := y;
                asm
         			inc tempbyte
                end;
                y := tempbyte;
                setnz(tempbyte);

                inc(cycles, 2);
                inc(pc);

            end;

  //*                                       *
  //*       iny instruction 2005/12/29      *
  //*---------------end---------------------*

  //*                                       *
  //*       jmp instruction 2005/12/29      *
  //*---------------start-------------------*
        $4C: //absolute
            begin

                inc(cycles, 3);
                tempbyte := memread(pc + 1);
                pc := (memread(pc + 2) shl 8) or tempbyte;

{$IFDEF debug}
                curIns := 'JMP $' + intToHex(pc, 0);
{$ENDIF}
            end;

  //*                                       *
  //*       jmp instruction 2005/12/29      *
  //*---------------end---------------------*

  //*                                       *
  //*       jmp instruction 2005/12/29      *
  //*---------------start-------------------*
        $6C: //indirect
            begin

				inc(cycles, 5);
                tempbyte := memread(pc + 1);
                taddr := (memread(pc + 2) shl 8) or tempbyte;
				tempbyte := memread(taddr);     //low address

				taddr:=(taddr and $ff00) or byte((taddr and $00ff) +1 );   //
                //high  address
				pc := (memread(taddr ) shl 8) or tempbyte;



{$IFDEF debug}
                curIns := 'JMP ($' + intToHex(pc, 0) + ')';
{$ENDIF}
            end;

  //*                                       *
  //*       jmp instruction 2005/12/29      *
  //*---------------end---------------------*


  //*                                       *
  //*       jsr instruction 2005/12/30      *
  //*---------------start-------------------*
        $20: //absolute
            begin

                inc(cycles, 6);
				taddr := pc + 2;

				push((taddr shr 8) and $00FF);
				push(taddr and $00FF);

				taddr := memread(pc + 1);
				taddr := taddr or (memread(pc + 2) shl 8);
                pc := taddr;

{$IFDEF debug}
                curIns := 'JSR $' + intToHex(taddr, 0);
{$ENDIF}
            end;

  //*                                       *
  //*       jsr instruction 2005/12/30      *
  //*---------------end---------------------*

  //*                                       *
  //*       lda instruction 2005/12/30      *
  //*---------------start-------------------*
        $A9: //immediate
            begin
{$IFDEF debug}
			    curIns := 'LDA #$' + intToHex(memread(pc + 1), 0);
{$ENDIF}

				a := memread(pc + 1);
				setnz(a);

                inc(cycles, 2);
                inc(pc, 2);
            end;

  //*                                       *
  //*       lda instruction 2005/12/30      *
  //*---------------end---------------------*

  //*                                       *
  //*       lda instruction 2005/12/30      *
  //*---------------start-------------------*
        $A5: //zero page
			begin

				taddr:=zpAddress(pc);
				a := memread(taddr);

{$IFDEF debug}
				curIns := 'LDA $' + intToHex(taddr, 0);
{$ENDIF}

				
                setnz(a);

                inc(cycles, 3);
                inc(pc, 2);
            end;

  //*                                       *
  //*       lda instruction 2005/12/30      *
  //*---------------end---------------------*

  //*                                       *
  //*       lda instruction 2005/12/30      *
  //*---------------start-------------------*
		$B5: //zero page,x
			begin
{$IFDEF debug}
                curIns := 'LDA $' + intToHex(memread(pc + 1), 0) + ',X ';
{$ENDIF}


				a := memread(izpaddress(pc,x));
				setnz(a);