En anglais

Fetch it, read it, run it

Computing · Computer Systems · ages 15-16

Name ______________________ Date ____________

Where does fetch grab the next instruction from?
- Memory
- The screen
- The keyboard
What is the correct order of the cycle?
- Decode, fetch, execute
- Fetch, decode, execute
- Execute, fetch, decode
Which part does the maths once decode has spoken?
- The cache
- The clock
- The ALU
Two chips share a clock, but one has double the cores. What best follows?
- It always runs exactly twice as fast
- It can chew more tasks side by side
- It needs no memory at all
A 3 GHz processor runs about how many billion cycles per second?
Answer: ______________
Why does a bigger cache make a machine feel faster?
- Recent bits wait nearby, so fetches hurry
- It raises the clock speed
- It adds more cores
Why must data sit in memory next to instructions during a run?
- Data looks nice beside code
- Memory deletes data otherwise
- Execute reads and stores its working values there
Two cores are always exactly twice as fast as one.
Circle one: True False

Answer key

For grown-ups. Fold this page away before handing over the rest.

Memory · Every next instruction waits in memory for its fetch.
Fetch, decode, execute · Each round fetches first, works out the meaning, then acts.
The ALU · The ALU crunches numbers and comparisons at execute time.
It can chew more tasks side by side · Each core runs its own cycle, so tasks advance in parallel.
3 · 3 GHz means about 3 billion rounds each second.
Recent bits wait nearby, so fetches hurry · Nearby copies spare the trek to main memory.
Execute reads and stores its working values there · Each step works on values waiting in memory, not only in storage.
False · Cores split parallel work, but some jobs refuse to split.