Central Processing Unit (CPU)

Central Processing Unit (CPU)

1. Purpose

   • Described as the brain of the computer. Its job is to process all data and complete instructions given by the user.

2. Factors affecting Performance

   • Clock Speed:
     • Indicates how fast a CPU can run and is measured in hertz (how many cycles/instructions the CPU can process in one second.
   • Number of Cores
     • The CPU contain one or more cores, such as, dual core or quad core processors. The more cores a processor has, the more able it is to run multiple programs at the same time.
   • Cache
     • Cache memory is a type of very fast memory situated on or very close to the CPU. It is used to temporarily hold instructions and data the CPU is likely to reuse.

3. Parts of the CPU

   • * Arithmetic Logic Unit (ALU)
     • This processes all data inside the CPU. As it name suggests it handles both Arithmetic (mathematical) operations and Logical operations.
   • * Immediate Access Store
     • Each piece of data is stored in the random access memory chip so that the CPU can retrieve data immediately. Each memory location has a unique address assigned to it.
   • * Register
     • Some registers are used in the fetch-execute cycle while others may be used by the program being executed. Registers are much faster to access because they have to be accessed so often.
   • * Control Unit
     • Manages how data is processed by the CPU; Manages how the CPU and other components communicate; Executes all instructions provided by programs; Informs the ALU, IAS along with input and output devices how to respond to instructions from a program.