Signals are sent to and from the components of a processor using buses. Identify and describe the purpose of two different buses. Bus 1 Purpose Bus 2 Purpose

Mark scheme

Marking points from the official mark scheme (May/June 2017). The mark or mark type is shown in brackets.

1. [6] 1 mark for correct bus name and up to 2 further marks for appropriate purpose. Address (bus) Two from: ∞ Carries / transports an address / location ... ∞ ... of the next item to be fetched ∞ Data travels one way (unidirectional) Data (bus) Two from: ∞ Carries / transports data / example of data ... ∞ ... that is currently being processed // that will be / has been processed ∞ Data can travel in both directions (bidirectional) Control (bus) Two from: ∞ Carries / transports signals ∞ Control / directs the actions of the CPU / processor ∞ Can be either Unidirectional or Bidirectional