Oxford Cambridge and RSA
GCSE (9-1) Computer Science
Computer Systems
J277/01
Topic: Von Neumann Architecture & Registers
Time allowed: 30 minutes
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INSTRUCTIONS INFORMATION
Turn over
1
Von Neumann architecture includes registers.
Identify two registers used in Von Neumann architecture.
[2]
2
Complete the table by writing the missing name of each register next to its correct definition.
[4]
Register Name Definition
Stores the address of the next instruction to be fetched from memory. Increments during each fetch-execute cycle.
Stores the result of mathematical calculations and logical operations.
Stores the address of the data to be fetched from or the address where the data is to be stored.
Stores the data or instruction that has just been fetched from memory.
Section B: Purpose & Function
3
Describe the purpose of the Program Counter (PC).
[2]
4
Describe the purpose of the Accumulator (ACC).
[2]
Turn over
5
The Memory Address Register (MAR) and Memory Data Register (MDR) work together during the fetch stage of the fetch-execute cycle.

Explain the difference between the data stored in the MAR and the data stored in the MDR.
[4]
Section C: The Fetch-Execute Cycle
6
Alicia has designed a computer using Von Neumann architecture.

Describe what happens during the fetch-execute cycle.
In your answer, you must refer to the registers.
[6]
END OF QUESTION PAPER