Power controller and power control method

A power control method comprising:

• a power detection step of detecting supply of first power given a predetermined power level and second power given a power level lower than the power level of the first power;
• a supply power switch step of supplying storage means for storing data in a storage medium with the first power when supply of the first power is detected in the power detection step and supplying the storage means with the second power after switching power source from the first power to second power when supply of the second power only is detected in the power detection step;
• and
• a data transfer rate control step of setting a data transfer rate between a predetermined data transfer source or data transfer destination and the storage means to a second data transfer rate lower than a first data transfer rate coupled with supply of the first power when supply of the second power only is detected, to thereby reduce power consumption of the storage means in comparison to power consumed by a data transfer at the first data transfer rate.

A power controller comprising:

• a power detector detecting supply of first power given a predetermined power level and second power given a power level lower than the power level given to the first power;
• a supply power switch supplying a storage for storing data in a storage medium with the first power when the power detector detects supply of the first power, and supplying the storage with the second power after switching power from the first power to the second power when the power detector detects supply of the second power only;
• and
• data transfer rate controller setting a data transfer rate between a predetermined data transfer source or data transfer destination and the storage to a second data transfer rate lower than a first data transfer rate coupled with supply of the first power when supply of the second power only is detected, to thereby reduce power consumption of the storage in comparison to power consumed by a data transfer performed at the first data transfer rate.