219 lines
3.5 KiB
Plaintext
219 lines
3.5 KiB
Plaintext
LDA LDX LDY BIT ADC SBC AND ORA EOR CMP CPX CPY
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=====================================
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LDA #imm
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FetchOperandLo
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FetchOpcode
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LDA ZeroPage
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FetchOperandLo
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ReadAddress
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FetchOpcode
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LDA ZeroPage,X
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FetchOperandLo
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IndexX
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ReadAddress;
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FetchOpcode
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LDA Absolute
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FetchOperandLo
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FetchOperandHi
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ReadAddress
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FetchOpcode
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LDA Absolute, X/Y
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FetchOperandLo
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FetchOperandHiAndIndex;
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ReadAddressAndSkip;
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ReadAddress
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FetchOpcode
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LDA (Indirect, X)
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FetchOperandLo
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IndexX
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FetchAddressLo;
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FetchAddressHi;
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ReadAddress
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FetchOpcode
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LDA (Indirect), Y
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FetchOperandLo
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FetchAddressLo
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FetchAddressHiAndIndex
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ReadAddressAndSkip
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ReadAddress
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FetchOpcode
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STA STX STY
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=====================================
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STA ZeroPage
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FetchOperandLo
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WriteRegister
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FetchOpcode
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STA ZeroPage, X
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FetchOperandLo
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IndexX
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WriteRegister
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FetchOpcode
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STA Absolute
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FetchOperandLo
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FetchOperandHi
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WriteRegister
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FetchOpcode
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STA Absolute, X/Y
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FetchOperandLo
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FetchOperandHiAndIndex
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ReadAddress
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WriteRegister
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FetchOpcode
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STA (Indirect, X)
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FetchOperandLo
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IndexX
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FetchAddressLo
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FetchAddressHi
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WriteRegister
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FetchOpcode
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STA (Indirect), Y
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FetchOperandLo
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FetchAddressLo
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FetchAddressHiAndIndex
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ReadAddress
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WriteRegister
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FetchOpcode
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ASL LSR ROL ROR INC DEC
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========================
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ASL A
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FakeFetchOperand
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FetchOpcode
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ASL ZeroPage
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FetchOperandLo
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ReadAddress
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WriteAddress
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WriteAddress
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FetchOpcode
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ASL ZeroPage, X
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FetchOperandLo
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IndexX
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ReadAddress
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WriteAddress
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WriteAddress
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FetchOpcode
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ASL Absolute
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FetchOperandLo
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FetchOperandHi
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ReadAddress
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WriteAddress
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WriteAddress
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FetchOpcode
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ASL Absolute, X
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FetchOperandLo
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FetchOperandHiAndIndex
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ReadAddress
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ReadAddress
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WriteAddress
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WriteAddress
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FetchOpcode
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BCC BCS BNE BEQ BPL BMI BVC BVS
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========================
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BCC
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FetchOperandLo
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CheckIfTaken;
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CheckIfPageCrossed;
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FetchOpcode
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CLC SEC CLI SEI CLD SED CLV
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===========================
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---
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MICROINSTRUCTIONS
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===========================================
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FetchOpcode
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DoOpcodeWork();
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IR = Mem::Read(PC++);
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Decode();
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ResetState();
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FakeFetchOperand
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Address.Lo = Mem::Read(PC);
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FetchOperandLo
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Address.Lo = B = Mem::Read(PC++);
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FetchOperandHi
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Address.Hi = Mem::Read(PC++);
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FetchOperandHiAndIndex
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Address.Hi = Mem::Read(PC++);
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if (Address.Lo+X/Y > 255) pageCrossed = true;
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Address.Lo += X/Y;
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ReadAddress
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B = Mem::Read(Address);
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if (pageCrossed) Address += 0x0100;
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ReadAddressAndSkip
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B = Mem::Read(Address);
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if (pageCrossed)
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Address += 0x0100;
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else
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InsertFetchOpcode();
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IndexX
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B = Mem::Read(Address);
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Address.Lo += X;
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FetchAddressLo
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T = Mem::Read(Address++);
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FetchAddressHi
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Address.Hi = Mem::Read(Address);
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Address.Lo = T;
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FetchAddressHiAndIndex
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Address.Hi = Mem::Read(Address);
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pageCrossed = (T+Y > 255);
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Address.Lo = T+Y;
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WriteRegister
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if ((IR&3)==1) Mem::Write(Address, rA);
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else if ((IR&3)==2) Mem::Write(Address, rX);
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else if ((IR&3)==0) Mem::Write(Address, rY);
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WriteAddress
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Mem::Write(Address, B);
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DoOpcodeWork();
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FetchOperandAndCheckBranch
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Address.Lo = B = Mem::Read(PC++);
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If (!condition)
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InsertFetchOpcode();
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else
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T = PC.Hi;
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PC = PC +(int8_t)B;
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CheckIfPageCrossed
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FakeFetchOperand();
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if (PC.Hi == T)
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InsertFetchOpCode();
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else
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pageCrossed = true;
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