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 NOT AND OR >= <= > < < > = Evaluates conditions Makes comparisons Can compare Numbers Letters Special characters AND OR >= <= > < < > =

Registers Special-purpose High-speed 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 Holds instruction currently being executed Data register 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