1. The fetch-execute cycle

2. Memory Address Register+1
Program Counter
Memory
Memory Address Register
Cell
Selector
Cells 69 70
Memory Data Register 71 72
Instruction
Register
Op Code
Operand 73
Instruction
Decoder
ALU

3. Fetch +1 Program Counter 072 071 Memory Memory Address Register 071 69
Cell
Selector
Cells 69 70
Memory Data Register
251 71
251 72
Instruction
Register 2 51
Op Code
Operand 73
Instruction
Decoder
ALU

4. Decode +1 Program Counter Memory Memory Address Register 69 70
Cell
Selector
Cells 69 70
Memory Data Register 71 72
Instruction
Register 2 51
Op Code
Operand 73
Instruction
Decoder
ADD
ALU

5. Execute +1 Program Counter Memory Memory Address Register 69 70
Cell
Selector
Cells 69 70
Memory Data Register 71 72
Instruction
Register 2 51
Op Code
Operand 73
Instruction
Decoder
ADD 51
ALU

6. Fetch +1 Program Counter 073 072 Memory Memory Address Register 072 69
Cell
Selector
Cells 69 70
Memory Data Register
226 71 72
Instruction
Register
226 2 26
Op Code
Operand 73
Instruction
Decoder 51
ALU

7. Decode +1 Program Counter Memory Memory Address Register 69 70
Cell
Selector
Cells 69 70
Memory Data Register 71 72
Instruction
Register 2 26
Op Code
Operand 73
Instruction
Decoder
ADD 51
ALU

8. Execute +1 Program Counter Memory Memory Address Register 69 70
Cell
Selector
Cells 69 70
Memory Data Register 71 72
Instruction
Register 2 26
Op Code
Operand 73
Instruction
Decoder 26
ADD 77 51
ALU

9. Exam question