Identify the bus that carries addresses in one direction only, from the CPU to main memory.
Mark scheme
- A Address bus (1)
- The only correct answer is A. The correct answer is address bus. Do not accept 'address' on its own.
- B is not correct because the control bus carries control signals in both directions between the CPU and other components
- C is not correct because the data bus carries data in both directions between the CPU and main memory
- D is not correct because the system bus is the collection of all three buses
Example answers and how they were marked
Full marks1/1
A Address bus
Why: Correct option: the address bus carries addresses in one direction only, from the CPU to main memory (1).
No marks0/1
C Data bus
Why: The data bus carries data in both directions, so it is not the bus that carries addresses in one direction only from the CPU to main memory; no creditworthy point.
No marks0/1
B Control bus
Why: The control bus carries control signals in both directions, not addresses in one direction only; this is the common control/address bus confusion, so no mark.