A Level Computer Science OCR Practice Exam

Which part of the bus is responsible for carrying information about data destinations?

1. Data Bus

2. Address Bus

3. Control Bus

4. Instruction Bus

The correct answer is: Address Bus

The address bus is responsible for carrying information about where data should be sent or retrieved from within a computer system. When the CPU wants to access memory or I/O devices, it sends the address of the destination storage location on this bus. This allows the system to know which specific memory location is being referenced for the read or write operation. In computer architecture, the address bus is separate from the data bus, which carries the actual data being transmitted, and the control bus, which carries control signals that help manage the operations of the computer. Each bus has a specific role, and the address bus is key for pointing to the locations in memory or the addresses of I/O devices, thereby ensuring that data is correctly routed in the system.