Computer Components Flashcards
Purpose of computer
take data, process it, output it
Created to help process data and complete tasks more efficiently than humans
embed system
computers built onto other devices, system that is part of a larger system
dedicated to a single task, easier to design , cheaper to produce, more efficient at doing their task than a general purpose computer
what is control unit
overall control of the CPU, mangage fetching decoding and executing of program instructions by following the f-e cycle
controls the flow of data inside the CPU and outside the CPU
what is the arithmetic logic unit
does all the calculations
perform simple addition subtraction and compares the size of numbers and can do multiplicationa dndivision using repeated additon…
perform logic operations and binary shifts
contains accumulator reigster
what is cache
very fast memory in the cpu
slower than register faster than ram
stores regularly used data so cpu can access it quickly next time it is used, cpu checks cache first before checking the ram
they have low capacity and are more expensive compared to ram and secondary storage
different levels of cache memory l1 is the quickest and has the lowest capacity. l3 slower more capacity…
Von Neumann architecture
a system where the CPU runs instructions stored in memory
programs consists of instructions and data which are stored in memory address
inside control unit
the program counter which holds the address of the instruction of each cycle
it increments
registers
memory address register MAR
holds memory address about to be used by the CPU. address might point to data or a CPU instruction
memory data register MDR
holds the actual data or instruction
arithmetic and logic unit
accumulator
stores intermediate result of calculation in the ALU
fetch decode execute cycle
fetch instruction
copy memory address from pc to mar
copy instruction stored in mar address to mdr
increment pc
decode instruction
instruction in MDR is decoded by CU, cu them prepair for the next step
execution Instruction
the instruction is performed.
this could be load data from the memory, write data to memory , calculation or logic operation (using the ALU) change address in PC, or halt the program
repeat
Virtual memory
Secondary storage used as RAM
when ram is filled with data it uses secondary storage
it moves data that has not recently being used into secondary storage
used when using memory intensive apps or too many apps opened at once
it slow as data need to be moved back to RAM to be read again by cpu
slow to respond when switching applications
ROM
tells computer how to boot up
contains BIOs
clock speed
number of instruction one processor carry out per second
higher Clock Speed more instruction can be carried out
some CPU can be overclocked it can make CPU overheat /crashes/ permanent damage to system.
cooling system is normally needed to accompany high performance
number of cores
each core process data independently to the rest.
more core means more instructions at once
cache size
data storage inside CPU faster than RAM
larger CPU gives the CPU faster access to more data it need to process
