Power Management
Among DRAM power-saving states, which describes self-refresh?
- AA low-power state in which the DRAM keeps refreshing itself to retain its contents even with no commands from the memory controller
- BA state that erases all DRAM contents
- CA state that doubles DRAM frequency
Show answer and explanation
Answer: A. A low-power state in which the DRAM keeps refreshing itself to retain its contents even with no commands from the memory controller
DRAM loses its contents without periodic refresh, normally commanded by the memory controller. In self-refresh, the DRAM keeps refreshing itself with an internal oscillator, so contents survive even with the memory controller and interface circuits shut down. It is used while PCs and smartphones sleep, allowing work to resume immediately on wake.
- A. Correct. It is used during system sleep and similar.
- B. Contents are retained.
- C. It does not raise frequency.