The fetch execute cycle

What is the CPU

CPU is part of the coputer system referre dto as the 'brains' of the computer. It's also known as the processor or microprocessor. It is responsible for excecuring a sequence of stored instructions called a 'program'. The program inputs data, it's processed, result is output on screen or printed out.

Bus system

Three buses: Control bus, Address bus, Data bus. They carry data, instructions, memory addresses between CPU and RAM memory. The input and output interfaces allow for communication with peripheal devices like Keyboards, monitors and hard disk drives.

Control bus

Used by CPU to communicate with decices connected to the computer through physical connections like cables or printed circuits. Controller sends and recieves signals from all over the computer. All processes therefore take place at the right time in the right order.

Address bus

When data is saved or loaded from memory the address at which it is to be stored or loaded must be sent. The address bus sends data in one direction from CPU to RAM.

Von Neumann Architechture

some defenitions:

Arithmetic logic unit- A unit in a computer that carries out arithmetical and logical operations.

Accumalator - a register in which intermediate arithmetic and logic results are stored.

Memory - is where programs are stored when they are ready to run. Each instruction and item of data in the program will have a memory address.

Control unit - controls the timing of operations by generating a clock signal. Operations take place at regular intervals according to this signal. decodes the opcode (the operation that the machine code ) part…