Hitachi Global Storage Technologies Japan, Ltd.

Kazuhiko Satake

Terumi Takashi

Katsuhiro Tsuneta

When the format control circuit detects bit synchronization information in a sector to be reproduced on a magnetic disk, the format control circuit activates a read gate signal for commanding to read out the sector from the magnetic disk. When symbol synchronization information on the magnetic disk is detected, a SYNC detection circuit produces a synchronization information detection signal. The format control circuit calculates an end position of the sector on the magnetic disk on the basis of the synchronization information detection signal to inactivate the read gate signal. The data correction circuit and the decoding circuit reproduce data and ECC in the sector read out from the magnetic disk during the period that the read gate signal is active on the basis of the synchronization information detection signal to produce the data and ECC to a data bus. The data flow control circuit processes the data and ECC on the data bus after the elapse of a reproduction delay time on the basis of the synchronization information detection circuit.

Data reproducing apparatus for improving data recording efficiency

The electromagnetic noise radiated from a magnetic disk system comprising two or more magnetic disk drives is reduced so as not to exceed a certain level although the electromagnetic noise from each magnetic disk drive is added up. This is achieved by setting a different operation clock frequency for each SCSI-ID so that the electromagnetic noise radiated from each magnetic disk drive has a different frequency band.

Growing community of inventors

Odawara, Japan

Kazuhiko Satake