Transcript The Central Processing Unit: What Goes on Inside the Computer

The Central Processing Unit:
What Goes on Inside the Computer
Computer Hardware and
Software Maintenance
The CPU
The CPU
• The brains of the computer system
• Converts data into information
• Control center
• Set of electronic circuitry that executes
stored program instructions
• Two parts
– Control Unit (CU)
– Arithmetic Logic Unit (ALU)
CPU Socket Connection
Socket X (X being any
numerical number) is a
descriptive term for the
way certain processors
plug into a computer
motherboard so that it
makes contact with the
motherboard's built-in
circuitry or data bus.
Example: LGA 1156
(Intel) or Socket
AM3+(AMD)
CPU Sockets
• Common sockets have retention clips
that apply a constant force, which must
be overcome when a device is
inserted. For chips with a large number
of pins, either zero insertion force (ZIF)
sockets or land grid array (LGA)
sockets are used instead. These
designs apply a compression force
once either a handle (for ZIF type) or a
surface plate (LGA type) is put into
place. This provides superior
mechanical retention while avoiding the
risk of bending pins when inserting the
chip into the socket
CPU Basic Component #1
Control Unit
CU
• Part of the hardware that is in-charge
• Directs the computer system to execute
stored program instructions
• Communicates with other parts of the
hardware
CPU Basic Component #2
Arithmetic / Logic Unit
ALU
Performs arithmetic operations
Performs logical operations
Arithmetic Operations
Addition
Subtraction
Multiplication
Division
Logical Operations
• Evaluates conditions
• Makes comparisons
• Can compare
– Numbers
– Letters
– Special characters
Registers
A processor register (CPU register) is one of a small set of data
holding places that are part of the computer processor.
A register may hold an instruction, a storage address, or any
kind of data (such as a bit sequence or individual characters)
Special-purpose
High-speed
Temporary storage
Located Inside The CPU
Instruction register
Data register
Holds instruction currently
being executed
Holds data waiting to be
processed
Holds results from processing
Executing Programs
• CU gets an instruction and places it in memory
• CU decodes the instruction
• CU notifies the appropriate part of hardware to take
action
• Control is transferred to the appropriate part of
hardware
• Task is performed
• Control is returned to the CU
Microprocessor(CPU)
• CPU etched on a chip
• CPU is made of Sand(silicon)
• Contains millions of transistors
– Electronic switches that can allow current to pass
through
Types(Brands) of
Microprocessors(CPU’s)
Intel
Cyrix
AMD
Computer Processing Speed
Time to execute an instruction
• Millisecond-one thousandth of a second.
• Microsecond-one millionth of a second
• Nanosecond- one billionth of a second
– Modern computers
• Picosecond-one trillionth of a second.
– In the future
Microprocessor(CPU) Speed
• Clock speed the operating speed of a computer or
its microprocessor, defined as the rate at which it
performs internal operations and expressed in cycles
per second.
• Common CPU Clock speeds…
– Megahertz (MHz) one million cycles per second,
especially within the processor
– Gigahertz (GHz) A thousand million cycles per
second within the processor