The present invention relates to a magneto-optical disk driver and method thereof which searches a desired track and embodies the identification (ID) information recorded on a disk to be read using a hardware, and then performs a correct search for a target track based on this ID data, for application to information storage systems.
Generally, an information storage system is a device which records information on such recording media as magnetic tape or optical disks, and reproduces the information recorded thereon.
For such an information storage system, when the target track is searched in a conventional magneto-optical disk driver (MODD), the method for reading the identification (ID) information, which represents such track information as the track number, sector number and cyclic redundancy check (CRC) code, will be explained referring to both FIG. 1 and FIG. 2.
Referring to FIG. 1, first, an interface controller 10 sends to a servo system 20 an instruction request signal and search instruction signal which together result in a proper transfer of an optical pickup to the target track. Then, servo system 20 transfers to interface controller 10 an instruction-received signal and an instruction-executed signal which together signify that the transfer of the desired track has been completed (steps S1-S4).
Then, interface controller 10 activates a read gate signal so as to read the ID data, and then analyzes a non-return-to-zero inverse (NRZI) signal, a read reference clock (RRCLK) signal, and an address mark detected (AMDET) signal from data demodulation means (not shown) which consists of a phase-locked loop (PLL) and an encoder. Interface controller 10, then determines whether the track is the desired one (steps S5-S8).
Next, if it is the desired track, interface controller 10 reads the ID data corresponding to the desired one and outputs an indication that the desired track has been reached, and if not, the interface controller 10 repeatedly transmits to servo system 20 a modified search instruction signal for performing a re-transfer operation by a difference value. When the instruction-received signal is received from servo system 20, interface controller 10 analyzes the NRZI, RRCLK and AMDET signals by re-operating the ID reading gate, and then determines whether the searched track is the desired one (steps S8-S12).
Here, steps S1 to S12 of FIG.2 are performed in interface controller 10 which connects to a host personal computer and optical disk driver.
As above, since all of the instructions are transmitted as serial data through the enhancement small device interface (ESDI) command line by the operation of interface controller 10 and servo system 20, a long time is required for the transmission. Also, several repeated executions of the instructions are necessary for searching the desired track, which further defers the searching time for the entire system.