1. Central Processing Unit (CPU)

2. Central Processing Unit (CPU)
‘Brain’ of the computer
Performs the change of data into information
Accepts data from any input device, changes this data according to instructions given by the user and send the result to an output device

3. Explains how computers process data (input- raw text, numbers) into information (output)

4. Central Processing Unit (CPU)
Consists of the
Control Unit
Arithmetic Logic Unit (ALU)
Registers

5. Control Unit Directs and coordinates the entire hardware system
Organises the flow of data in a computer
Similar to traffic lights controlling the flow of traffic
It interprets each instruction given by a program and gives appropriate action to be carried out

6. Arithmetic Logic Unit (ALU)
Performs data calculations including addition, subtraction, division and multiplication
Performs comparisons on data items

7. Registers
Temporary storage area for small amounts of data or instructions before and after processing.
Some of the different registers are:
Accumulator Register – stores data to be processed
Buffer Register – stores data coming from or being sent to primary storage, e.g printing a document
Address Register – stores location of data in primary storage
Instruction Register – stores the address if the next instruction to be processed

8. Microprocessor
A central processing unit contained on one integrated circuit
If the processor is built onto a single microchip it is called a microprocessor
Used in PC’s, cameras, DVD players etc.

9. Development of CPU speeds
Moore's Law - the number of transistors per integrated circuit doubles about once every two years, while the price of the chip remains the same.

10. Development of CPU speeds
Intel's graph showing growth in the number of transistors over the past 35 years

11. Development of CPU speeds

12. Central Processing Unit (CPU)
Questions:
Describe the role of the CPU.
List and explain the three parts of the CPU
What is a microprocessor and where are they used?