1.1 systems architecture Flashcards
What’s a computer
Electronic device which takes an input, processes data and delivers an output
Input examples
Keyboard, mouse, touchscreen, microphone, game controller
Output examples
Speaker, printer, projector, screen
Purpose of the CPU
Fetch, decode and execute instructions
What is/what happens during fetch
Fetching the next instruction from the min memory (RAM)
Brings the instructions back to the CPU
What happens during decode
Inspects the instruction and works out what needs doing
What happens during execute
Carries out the instruction
What does the ALU (arithmetic logic unit) do
Performs calculations and logical decisions
What does the CU (control unit) do
Sends signals to control how data moves around the CPU
What does cache do
Provides fast access to frequently used instructions and data
What do registers do
They’re tiny, super fast pieces of onboard memory inside the CPU with very specific purposes
What did john von Neumann do
Developed the stored program computer. Both programs and data are stored in memory
What the the PC (program counter) do
Holds the address of the next instruction in memory
What does the MAR (memory address register) do
Holds the address of where data is to be fetched or stored
What does the MDR (memory data register) do
Holds the data fetched from, or to be written to memory
