Power Management
What is the main purpose of dividing an SoC into multiple power domains?
- ATo cut total power by setting each block's voltage to its performance needs and powering off only idle blocks
- BTo ensure all blocks always run at the same voltage
- CTo shrink the chip area
Show answer and explanation
Answer: A. To cut total power by setting each block's voltage to its performance needs and powering off only idle blocks
CPU cores, the GPU, memory controllers and small always-on management circuits differ in the performance they need and in when they run. Separate power domains let only the blocks that need speed run at high voltage, idle blocks be powered off and only essential circuits stay powered during standby. Boundaries need level shifters and isolation cells, making design and verification more complex.
- A. Correct. Power can be managed at a fine grain.
- B. With one voltage there would be no need to split.
- C. The extra circuitry actually increases area.