Central Processing Unit and Cooling Systems May 2016 | Page 20

CPU is now finished with this instruction and places a ‘tick’ next to the number 1, to keep track of which instruction to ask for
next.
CPU asks for (fetches) the instruction (add 6 to y) from the Memory
CPU asks the value of y from the Memory.
CPU adds 6 to the value of y and tells the Memory to store the new value for y.
CPU is now finished with this instruction and places a ‘tick’ next to the number 2, to keep track of which instruction to ask for
next.
CPU asks for (fetches) the instruction (plot x, y) from the Memory
CPU asks the value of x from the Memory.
CPU asks the value of y from the Memory.
CPU tells the Display to plot the value of x and y.
etc.

1. What happens if the CPU tells the display to plot an x or y value that is greater than 9?
2. What happens if the CPU is faster than the display?
3. What happens if the display is faster than the CPU?

Extra activity II – The Game, (Whiteboard)