Abstract: A method for rebuilding a mapping table of a solid state disk includes maintaining the mapping table saved on the buffer memory dynamically, backing up the mapping table regularly, processing user data and a backup mapping table simultaneously for writing to a flash memory array, recording differences between the mapping table and the backup mapping table simultaneously during a backup period, backing up the differences to the flash memory array continuously after the backup mapping table is written to the flash memory array, reading the backup mapping table and backup differences after power is turned on, and rebuilding the backup mapping table according to the backup differences in the buffer memory.

Abstract: A backup method for the mapping table of a solid state disk is provided. When access of a user data and writing of backup data units are processed at the same time, by adjusting a data volume of each of the backup data units and a length of a time lag interval, the data volume of the backup data units to be processed is reduced. More capacity will be available for processing access of the user data. Thus, the access efficiency of the user data is maintained.

Abstract: A device and method for power loss protection in solid state drive are provided. A power loss region is created in a flash memory array and reserved as an independent storage space for storing power loss backup. When the power is interrupted, the SSD halts the operation of the host. Before the backup power is used up, the buffered data is directly written to a blank power loss block of the power loss region to form a power loss backup, and an auxiliary mark is created for confirming the most updated power loss backup. After the power is resumed, the power loss backup is directly read from the power loss region according to the most updated power loss auxiliary mark of the power loss backup to restore the original state of the SSD before the power is interrupted.

Abstract: A method of collecting a garbage block includes determining if a process of collecting the garbage block is being executed when a write command is received, copying effective pages of the garbage block to a target block in the spare area, terminating the process of collecting the garbage block, and writing data according to the write command

Abstract: A method for determining phase difference of tracking error (TE) signal is disclosed. The method includes following steps. An optical disc drive is activated to generate a TE signal. Amplitudes of the master push pull (MPP) signal, the secondary push pull (SPP) signal and the TE signal are measured. The phase difference between the MPP signal and the SPP signal of the TE signal is quickly calculated according to the law of cosine.

Abstract: A discrimination method of an optical disc. The method includes: focusing a light spot on a rewritable zone of the optical disc; reading an EFM signal of data marks of the optical disc to check if the optical disc is a data disc or a blank disc; when the optical disc is a data disc, utilizing an SBAD signal for discrimination of the optical disc; when the optical disc is a blank disc, utilizing a DPD signal for discrimination of the optical disc; checking if the header signals exist or not; identifying the optical disc as a DVD-RAM disc if the header signals exist; and identifying the optical disc as a DVD-RW disc if there is no header signal. In this way, the accuracy of the optical disc discrimination is enhanced.

Abstract: An auxiliary track seeking method includes detecting a deviation signal corresponding to a positional difference between a fine actuator and a coarse actuator; judging a track seek direction; determining if the deviation signal is greater than a deviation threshold value; detecting whether a number of times of applying a voltage pulse is less than a predetermined number; applying the voltage pulse to push the coarse actuator and thereby adjust the deviation signal toward the deviation threshold value, a time duration and an amplitude of the voltage pulse being predetermined as fixed or variable; accumulating the number of times of applying the voltage pulse; repetitively exerting the voltage pulse until the deviation signal value reaches the deviation threshold value; and resetting the accumulated number of times of exerting the voltage pulse to zero and then ending the tracking seeking to thereby reduce track seeking failures.

Abstract: A seeking method of an optical disc drive includes steps of (a) calculating a deviation signal value between a location of a fine actuator and a coarse actuator, (b) judging whether or not the deviation signal value is within a deviation signal threshold interval, (c) outputting a characteristic value to push the coarse actuator if the deviation signal value is not within the deviation signal threshold interval, and (d) jumping to a target track.