Microprocessor unit (MPU) is the heart of every microcomputer. It performs a number of functions, including.
- Providing timing and control signals for all elements of the microcomputer (μC).
- Fetching instructions and data from memory (Fig. 48.1).
- Transferring data to and from memory and I/O (input/output) devices.
- Decoding instructions.
- Performing arithmetic and logic operations called for by instructions.
- Responding to I/O-generated control signals such as RESET and INTERRUPT.
The MPU contains all of the logic circuitry for performing these functions, but its internal logic is not externally accessible. Instead, we can control what happens inside the MPU by the program of instructions that we put in memory for the MPU to execute. ...