Hardware interview practice
Choose a low-power technique for a short idle interval
A compute block is idle for tens of cycles at a time. Its state must be preserved, it must resume in one cycle, and switching power is the dominant component. Which technique best matches these stated constraints?
Choose one
Answer choices
- A. Use glitch-free clock gating while idle so state is retained and clock-tree/sequential switching stops.
- B. Leave the clock running and add isolation only at the block outputs; isolation removes internal switching activity.
- C. Replace every cell with a low-threshold cell because that primarily reduces switching power without affecting leakage.
- D. Power-gate the block without retention on every idle interval, then reconstruct its lost state in one cycle.