Adaptive system and method for spinning a polyphase disk drive motor from a stationary position

摘要

A method and system are disclosed for spinning the spindle motor of a disk drive from a stationary state to an operable state that is suitable for performing a memory access operation. The method and system include energizing the polyphase motor in a first predetermined commutation phase; detecting whether a zero crossing of a back electromotive force (bemf) signal corresponding to the first predetermined commutation phase occurs; sensing whether the polyphase motor advanced to a next successive commutation phase relative to the first predetermined commutation phase; and performing an acceleration procedure to accelerate the speed of the polyphase motor towards a desired speed based upon a detected zero crossing of the bemf signal and an affirmative determination that the polyphase motor advanced to a next successive commutation phase relative to the first predetermined commutation phase.