Unit 1.1 Flashcards
What is a computer?
An electronic device that takes input, processes data and delivers output
What does the CPU carry out?
The fetch-decode-execute cycle
Explain the fetch cycle
The CU sends signals to load the address of the PC into the MAR. The data in that address is then fetched from memory then stored in the MAR
Name the 4 components of the CPU
Arithmetic Logic Unit
Control Unit
Registers
Cache
What does the ALU do?
Carries out arithmetic calculations and makes logical decisions
What does the CU do?
The Command and Control center of the CPU
Sends signals to control how data moves around the CPU
The “decode” stage happens here
What is the cache?
A small amount of fast memory that provides quick access to frequently used data and instructions.
It is quicker to fetch data from cache than from RAM
What are registers?
Tiny, super fast pieces of memory stored inside the CPU, with each having a specific function
What does the Accumulator do?
Holds the results of caluclations
What does the Program Counter do?
Holds the address of the next instruction
What does the Memory Address Register do?
Holds the address of where data is to be fetched or stored
What does the Memory Data Register do?
Holds the data that is to be fetched or stored
What is the Von Neumann architecture based on and what does it mean?
The stored program computer concept (Programs are stored in memory instead of having to manually input)
Computers with the Von Neumann architecture store instruction data and program data in the same memory (RAM)
What are the factors affecting the speed of the CPU?
Clockspeed
Number of Cores
Cache Size
What is clockspeed?
The number of fetch-execute cycles per second
measured in Hz
The higher the clockspeed the quicker the CPU
