The control unit controls other units by generating control signals (often including timing signals) that tell each component what to do and when to do it.

These control signals:

  • Direct the ALU which operation to perform.
  • Coordinate data movement between registers, memory, and I/O devices.
  • Synchronize operations in the CPU using timing signals or clocked sequences.

In many exam-style questions, the expected one‑phrase answer to “What does the control unit generate to control other units?” is:

Control signals (timing and control signals).

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