Explain how the fetch execute cycle works? Include the specific registers and buses being used

During the fetch stage intitially the address of the next instruction from the program counter(PC) is loaded into the memory address register(MAR). This address is then sent via the address bus to main memory where the instruction is then retrieved from memory and sent back to the cpu via the data bus. It is then loaded into the memory buffer register (MBR) before the instruction is loaded into the Current Instruction Register(CIR). Simultaneously the PC is incremented so that it holds the address of the next instruction. The instruction in the CIR is decoded and extra data is fetched if necessary. Finally the instruction is executed using the Arithmetic Logic Unit (ALU) if necessary and store the result inside a register

TB
Answered by Thomas B. Computing tutor

3837 Views

See similar Computing A Level tutors

Related Computing A Level answers

All answers ▸

Outline the differences between how a compiler and an interpreter works, and explain the advantages and usage of of each [12 marks]


What is the difference between simplex, half duplex and full duplex?


How do I make simplifying Boolean algebra easier?


What is the denary equivalent of the hexadecimal number A7?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning