components of a computer system (1)
- Created by: m_hannah2911
- Created on: 22-01-20 20:34
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- Components of a computer system
- Computer systems
- A computer is a machine that processes data.
- The purposes of a computer...
- to process data and output it
- to complete tasks more efficently than humans
- contains hardware and software
- The purposes of a computer...
- Hardware is the physical parts that make up a computer system
- For example: the CPU, motherboard, monitor and printer.
- Software is the programs and applications that a computer system runs
- For example: an operating system, a word processor or a video game.
- Embedded systems
- They are computers built into larger devices, usually dedicated systems so are usually used as control systems
- For example: dishwashers, microwaves and TVs
- they're dedicated to a single task so are usually easier to design, cheaper to produceand more efficent.
- They are computers built into larger devices, usually dedicated systems so are usually used as control systems
- A computer is a machine that processes data.
- The CPU - central processing unit
- the brain of the computer
- it processes all of the data and instructions to make the systems work
- the processing power of the CPU depends on: clock speed, cache size and number of cores
- It has three main parts
- the control unit (CU) - it's main job is to execute program instructions by following the fetch-decode-execute cycle.
- it also controls the flow of data inside the CPU (eg registers, ALU, cache) and outside the CPU (eg main memory and input/output devices
- the arithmetic logic unit - it's main job is to do all of the calculations
- it performs addition, subtraction, multiplication, divison and comparison between numbers it also performs logic operations such as AND, OR and NOT and binary shifts
- it contains the accumulator
- the cache - it is very fast memory but slower than the registers but faster than RAM.
- it stores regularly used data so that it can be accessed by the CPU quickly. Caches have a very low capacity and are expensive
- there are different levels of cache memory, L1, L2, L3. L1 is the quickest but has the lowest capacity, whereas L3 is the slowest but can hold the most
- the control unit (CU) - it's main job is to execute program instructions by following the fetch-decode-execute cycle.
- It follows the fetch-decode-execute system
- fetch:- copys the memoory address from program counter to MAR then, copy the instruction stored in MAR to the MDR.
- decode:- the instruction in MDR is decoded by CU which then prepares for the next step (eg by loading values)
- execute:- the instruction is performed (eg load data from the memory)
- decode:- the instruction in MDR is decoded by CU which then prepares for the next step (eg by loading values)
- fetch:- copys the memoory address from program counter to MAR then, copy the instruction stored in MAR to the MDR.
- Memory
- RAM
- high-speed
- volatile memory - temporary, requires power to retain its data
- RAM
- Computer systems
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