systems architecture Flashcards
what is a computer
a computer is an electronic device that takes input, processes data and delivers output.
what does CPU stand for
central processing unit
explain the fetch - decode - execute cycle
FETCH - CPU fetches instruction from computers main memory (RAM) and then brings it back to the CPU
DECODE - CPU inspects the instruction and then works out what it needs to do
EXECUTE - CPU carries out instruction.
give three examples of execution
- going back to main memory and grabbing some data
- performing a calculation
- storing information back into main memory
what is the ALU’s function
arithmetic logic unit is responsible for carrying out all arithmetic calculations and making logical decisions
what is the control unit (CU)
control unit sends signals to control how data moves around the CPU and coordinates the CPU’s operations
what is the cache
small amount of very fast memory that provides fast access to frequently used instructions and data
what are the registers
A…… , M…A…R…. , P… C… , M….D….R…
tiny super fast pieces of onboard memory inside the CPU
- accumulator
- memory address register
- program counter
- memory data register
what is the program counter PC
holds address of next instruction to be fetched
