Computer Architecture

CPU

Processes data and instructions input into the computer and outputs the results

Microprocesser

Integreted circuit on a single chip

Arithmetic Logic Unit (ALU)

Carries out required Arithmetic and Logic operations when program is being run (+ and -)

Control Unit (CU)

Ensures synchronisation of data flow and program instructions

Current Instruction Register

Stores current instruction being decoded and executed

Accumulator (ACC)

Stores data temporarily when ALU is carrying out operations

Memory Adress Register (MAR)

Stores data of the memory location currently being written or being read from

Memory Data Register (MDR)

Stores Data that has just been read from memory or about to be written to memory

Program Counter

Stores address of the next instruction going to be read can be found

Address Bus

Carries out Memory adresses from the processor to the rest of the components (unidirectional)

Data Bus

Carries out data from the processor to the rest of the components (bidirectional)

Control Bus

Carries Control signals from the processor to the rest of the components

Fetch

1. The memory address is copied from the PC to the MAR

2. The MAR places the memory address on the address bus

3. The address bus transfers the memory address to the MDR

Decode

The Memory Address is then decoded

Execute

The computer sends the data as control signals to the appropriate components so it can be carried out

System Clock

Sends pulses to synchronise the components (Higher Frequency = Faster Performance) however overclocking can occur

Cores

Stores ALU, CU and all the registers (More Cores = Better Performance but not necessarilly as CPU has to communicate with all the cores)

Caches

Unlike RAM, its stored on the CPU and stores regularly used data and instructions to access faster (Bigger Cache = Better CPU performance)

Instruction Set

List of all the commands that can be processed by a CPU, and the commands are machine code

Embedded Systems

An embedded system is used to perform dedicated functions (e.g- Security systems, Appliances, Cars)