Computer Essentials – Chapter 2

Transistor: an electronic component, composed typically of silicon, that opens or closes a circuit to alter the flow of electricity to store and manipulate bits.

Integrated circuit: Also called chips, used to store and process bits and bytes. This is a way to combine multiple transistors into a single module.

Central Processing Unit (CPU): A group of integrated circuits that work together to perform the processing in a computer.

Motherboard: The primary circuit board of a computing device. The microprocessor and other supportive chips are housed on circuit boards where embedded pathways electronically join the chips together.

These pathways are called buses

Central Processing Unit (CPU) has three (3) parts:

1. Arithmetic Logic Unit (ALU)Carries out mathematical and logic instructions

2. Control UnitSequentially accesses program instructions and coordinates the flow of data in and out of ALU, registers and RAM

3. RegistersHold the bytes currently being processed. Storage within the processor.

MultiCore Technology: more than one CPU on a chip

RAM: temporary (volatile) memoryData flows between the XPU and RAM across the front side bus (FSB)

Front Side Bus: Electronic pathways between the CPU and RAM

TransistorComposed of semi-conducting material that opens or closes a circuit

Integrated circuits Thin slices of silicon crystal packed with microscopic circuit elements

Wires Transistors Capacitors Logic gates Resistors

Used to store and process bits and bytes in today’s computers Central processing unit

o Group of integrated circuits that perform processing

Microprocessor

o CPU circuits packed onto a smaller module

Motherboard o Primary circuit board of a computing device o houses all essential chips and provides connecting circuitry

between them

Machine Cycle: (2 phases)1.Instruction Phase

Fetch Information

Decode Information2.Execution Phase

Execute the instruction

Store Results

System clock Produces a series of electronic pulses at a predetermined rate called clock speed

Clock Speed -- Measured in megahertz (MHz) or gigahertz (GHz)

Wordlength Number of bits that a CPU can process at once

MIPS: Millions of instructions per second Amount of time it takes to execute an instruction

Cache -- measured in MB or KB Temporary high-speed storage areasThree levels of cache are used in today’s personal computers. These levels

indicate the cache’s closeness to the CPU.L1 – same chip as the microprocessorL2 and L3 are on separate chipsCache is more expensive than RAM.

Things that effect a computer’s performance:RAMClock SpeedCacheWord Length

Moore’s Law

Continued increase in technological innovations causes transistor densities in an integrated circuit to double every 18 months

• Multiprocessing o Uses more than one processing unit o Examples:

Parallel processing Links several microprocessors to operate in

parallel • Multi-core processing

Incorporates two or more processor