comp org

• internal properties of the comp in perspective of the hardware
• physical components working

comp architecture

• viewed from perpective from the programmer
• desighn of the comp system
• logical component workin

what is comp?

• its an electronic device used to process data into useful info for people
• data represents raw facts(digital data)
• user is an essential part of the system

functional units of a comp

cpu, memory, input, output

memory -stores the info

alu -performs arithmetic and logical units

control unit- controls alu

info in a comp

instructino+data = info

instru include tranfer info, perform alu

set of instruction to perform task is called a program

process fetcher form memory and perfors data

• data

  data are digital info

could be num, encode char

nums are usually in BCD format

Input unit

source prog fed into a comp its an interface b/w input device and memory

memory unit

• primary memory and * secondary memory

stores instruction and data

primary mem:

fast ,operates at electronic speed,

process:

reads info and read/writes to the memory during exection

fetched one bit at a time

group of bit stores or retrieved at a time is a word [group of bit == word][group of bit length == word length]

address: is associated with the word location

mem unit

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RAM povides fixed access time independent of the location of the word

time req to access one word is called memory access time

ROM -read only (stores bios)

mem and process commucate with each othe in order to read/write info

to reduce comm time a small amount of RAM is tightely coupled with the process .It is known as Cache.

• Primary storage

insuficaent to store large data

fast ,smallest unit is cache

• secondary storage

  to store lage amount of data

ALU

arthmetic - adition ,sub

logical -comparison

access time of general purpose registers are faster than cache

output unit

inface with output device

converts info into binary

control unit

accepts info(input)

stores the info(memo)

process the info(alu)

provides info(out)

control units generates the timimg signals which determines when a particular operation takes place