Unit 2: Computer Architecture

CPU (Central Processing Unit)

a hardware component of a computer and can perform basic arithmetic, logical or input/output operations, in order to process data from input devices into useful information

CU

Responsible for the operation of CPU, controlling the retrieval of instructions from the primary memory as well as the sequence of their execution

PC (Program Counter)

A register that holds the address of the next instruction to be executed

CIR (Current Instruction Register)

A register that contains the current instruction carried out by the processor and decodes the data into a readable format

Memory Address Register (MAR)

A register that holds memory address for data or a instruction about to be used by the CPU

Address bus

Connector which carries the address of memory locations used to store data and program instructions.

Data bus

Connector which carries the actual information.

Memory Data Register (MDR)

a register that contains the data value being fetched or stored

Register

A small storage location that can hold data, usually multiple of 8 bits

ALU (Arithmetic Logic Unit)

Responsible for basic arithmetic, logical or input/output operations.

Accumulator (ACC)

Stores the results of any arithmetic or logical operations carried out by the ALU and sends data back to the memory.

RAM (Random Access Memory)

Primary Storage device which stores the executing program instructions as well as any data that is needed. The data stored can be overwritten.

ROM (Read Only Memory)

Primary storage device which stores the program permanently. Those program is required to boot the computer. The data stored cannot be easily overwritten but only read.

Primary Memory

Memory that is directly accessible by the processor

Cache memory

SRAM placed between DRAM and the processor as a temporary storage for blocks of recently used program instructions

Persistent storage

As RAM is volatile and ROM cannot be overwritten, information to be stored is sent to the persistent storage

OS (Operating System)

Peripheral communication, concurrent processing, memory management, resource management, security, program/data management, network management, user interface

OS (Operating System)

a system that coordinates interaction between the hardware, other software and the user

Range of application software

Word processor, spreadsheets, database management systems, email, web browsers, computer-aided design and graphic processing software

Application Software

software program that helps you use the computer to do particular tasks

Common features of application

Toolbars, menus, dialogue boxes, graphical user interface

System software

Programs that control or maintain the operations of a computer and its devices.

OS + utility software

Integers representation

Characters representation

Colour representation

Pixel

Hexadecimal color code

Each color in each pixel is represented by 6 digit hexadecimal value. Each two values represent red, green, blue