| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and a system which start rotation of a spindle motor for a disc drive from a stationary state into an operation-enable state which is suitable for memory access operation. SOLUTION: A multiphase motor is energized with a first prescribed commutation phase. Whether zero-crossing of a counter electromotive force (bemf), corresponding to the first prescribed commutation phase, is produced. Whether the multiphase motor is advanced to a commutation phase relatively consecutive to the first prescribed commutation phase. According to the detection of the zero-cross of the bemf signal, the affirmative determination of that the multiphase motor is advanced to the commutation phase relatively consecutive to the first prescribed commutation phase, and acceleration procedure for accelerating the speed of the multiphase motor toward a required speed is executed. |
