CPU + System Architecture

Question 1

What is PC

Answer 1

PC (Program Counter) holds the memory address of the next instruction from the memory

Question 2

What is MAR

Answer 2

MAR (Memory Address Reader) holds the memory address and retrieves the data

Question 3

What is MDR

Answer 3

MDR (Memory Data Reader) holds the address - copied from the MAR - or retrieves data from the memory

Question 4

What is the ACCUMULATOR

Answer 4

The accumulator holds results/data that have been processed - either from ALU or RAM

Question 5

What is CU

Answer 5

CU (Control Unit) controls all the signals and arranges all the instructions

Question 6

What is ALU

Answer 6

ALU (Arithmetic Logic Unit) performs all arithmetic and logic calculations

Question 7

What are 3 things that can affect a CPU’s performance

Answer 7

Clock Speed (number of fetch-execute-decode cycles (Hz)) - in a core

Number of Cores (has all registers + CU, ALU)

Cache size (bigger cache size, the more instructions it can do)