Cambridge O Level Computer Science · Syllabus 2210 · Hardware
Accumulator
What is Accumulator?
The CPU register that stores the intermediate and final results of arithmetic and logic operations, communicating with the arithmetic logic unit; it is one specific named register, not a general term for any register.
This definition is part of the Hardware chapter in Cambridge O Level Computer Science.
Common mistakes with Accumulator
- 9. “Execute always means performing arithmetic.” Why wrong Many instructions never touch the ALU — storing a value, loading a value, jumping to an address, sending data to a device. Correct model In execute, the control unit sends the signals needed to carry out whatever the instruction was, using the ALU only when a calculation, logical operation or comparison is required. Exam-safe “The control unit sends the control signals needed to carry out the instruction, using the ALU where a calculation, logical operation or comparison is required.” Check: is the ALU used when executing STO 302?No. Storing the accumulator's value at an address moves data; no calculation is performed.
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