INFORMATION PROCESSING CYCLE
INFORMATION PROCESSING CYCLE
• We looked at input already, now we are
moving on to the next step
WHAT IS THE NEXT STEP?
PROCESS
• If you said process, you are
CORRECT
VERY GOOD
PROCESS
• The name of the component that does all the
processing is called the
CENTRAL PROCESSING UNIT
OR
CPU
CENTRAL
PROCESSING
UNIT
(CPU)
CENTRAL PROCESSING UNIT
• The CPU is responsible for interpreting and executing most of
the commands the computer’s hardware and software
• It is considered the ‘brain’ of the computer
• It is also known as :
– Processor
– Computer processor
– microprocessor
• A modern CPU is usually small and square with many short,
rounded, metallic connectors on its underside. Some older
CPUs have pin instead of metallic connectors
CENTRAL PROCESSING UNIT
• The CPU has three (3) main parts, namely:
–CONTROL UNIT (CU)
–ARITHMETIC/LOGIC UNIT (ALU)
–REGISTERS
CENTRAL PROCESSING UNIT
Control
Unit
R
e
g
i
Arithmetic
/ Logic
Unit
s
t
e
r
s
CONTROL UNIT
• This is the main part of the CPU. Input is first
sent to the CU, from where it is then sent to
the allocated part of the computer to be
processed.
• The CU decides where to send data to be
processed. After processing, the information is
returned to the control unit.
ARITHMETIC /LOGIC UNIT
• This section performs all the arithmetic and
logic functions in a computer.
• For example, if an instruction involves an
arithmetic operation such as addition (+),
subtraction (-), multiplication (*) or division (/)
or the comparison of data.
ARITHMETIC /LOGIC UNIT cont’d
• The CU sends that data to the ALU for
processing. Some of the logic functions are
comparisons such as:
– Equal to (=)
– Less than (<)
– Less than or equal to (<=)
– Greater than (>)
– Greater than or equal to (>=)
– Not equal to (< >)
REGISTERS
• This section within the CPU are special
purpose temporary storage locations.
• It keeps track of the instructions to be
executed
REVISION
QUESTION AND ANSWER (T/F)
1. CPU stands for central progressive unit
2. A processor will translate the instruction so the
computer can perform tasks
3. All processors are called microprocessors
4. A processor does any and all calculations, sorting and
other changes made to data
5. The unit of measurement is bytes
6. The CPU is the main part of the computer system
7. The control unit sends data from the memory to the
ALU for processing
8. A register can hold data permanently
Reference
• http://www.google.com.jm/search?hl=en&q=WH
AT+IS+THE+CPU&gs_sm=e&gs_upl=8952l13190l0
l14314l15l9l0l0l0l0l1392l6144l41.1.3.2l7l0&bav=on.2,or.r_gc.r_pw.,cf.osb&biw=1
366&bih=545&um=1&ie=UTF8&tbm=isch&source=og&sa=N&tab=wi
• CPU Images
• http://homepage.cs.uri.edu/faculty/wolfe/book/
Readings/Reading04.htm
• CPU diagram
Reference cont’d
• http://library.thinkquest.org/C0125787/CPU.h
tm
• History of computer