Final answer:
An eight-bit microprocessor includes a CPU, Registers, ALU, Control Unit, MAR, MDR, PC, IR, and I/O control. It operates by fetching, decoding, and executing instructions in a sequence. A timing diagram for this process would show control signal sequences, which are not depicted due to textual limitations.
Step-by-step explanation:
The student has asked for a functional block diagram of an eight-bit microprocessor and an explanation of its working, along with a timing diagram for reading an instruction from the memory and executing it. While I cannot draw diagrams here, I can describe the essential components of an eight-bit microprocessor block diagram.
An eight-bit microprocessor typically includes the following functional blocks:
- Central Processing Unit (CPU)
- Registers including Accumulator (A), B register, and others
- Arithmetic Logic Unit (ALU)
- Control Unit (CU)
- Memory Address Register (MAR)
- Memory Data Register (MDR)
- Program Counter (PC)
- Instruction Register (IR)
- Input/Output control
The microprocessor operates by fetching an instruction from memory into the Instruction Register (IR). The Control Unit (CU) deciphers the instruction and signals the relevant parts of the processor to carry out the operation. This often involves using the ALU to perform arithmetic or logic operations. Instructions are fetched and executed in a sequence determined by the Program Counter (PC) which points to the next instruction.
As for the timing diagram, it shows the sequence of control signals sent by the CU to the various components within the microprocessor for reading an instruction from memory. Typical signals include Memory Read, Instruction Register In, and Execution phase signals. During the Memory Read phase, the address of the instruction is sent to MAR from PC, and after reading, the instruction is captured by the IR. Then, during the Execution phase, the instruction is decoded and the necessary operation is carried out.
Note that diagrams and detailed timing sequences are not provided here due to the text-based nature of this platform.