Registers

Current Instruction Register

The register stores the current instruction being decoded and executed

Accumulator

Stores data temporarily during ALU arithemic calculations

MAR

The MAR holds the address of the memory location while that location is being read from or written to.

MDR

The MDR stores data that is being read from memory or data that is being written to memory.

Program Counter

The PC (Program Counter) is a register that stores the address of the next instruction in memory that the CPU will fetch.

Control Bus

Carries signal from control units to all computer components (Bidirectional)

Data Bus

Carries data from cpu to memory (vice versa) and to and from input/output devices (Bidirectional)

Address Bus

Carries address throughout the computer system (Unidirectional)

Cache

A small fast primary memory that stores data and instructions temporarily so CPU can access to it faster than accessing it from RAM

RAM

A primary memory that stores data and instructions temporarily so CPU can access to the data quickly than accessing it from hard-drives (SDD and HDD)

Primary and Secondary memory

Primary memory is a volatile memory directly accessible by CPU whereas secondary memory are not and is non-volatile memory, it must load in to primary memory first before CPU can access to it

Fetch

The PC contains the address of the next instruction to be fetched. This address is copied into the MAR using address bus. The instruction at that address is then fetched into the MDR, which copies it into the CIR for decoding. Meanwhile, the PC is incremented by 1 ready for the next instruction. The instruction is finally decoded then executed by sending out signals using control bus to all computer components

Microprocessor and CPU

microprocessor is a small physical chip built to function as a CPU and CPU is a role of functions in computer.

Microcontroller

A microcontroller is a single chip that contains a CPU, memory, and input/output interfaces, making it a complete mini-computer for controlling devices