公开(公告)号：SG42862A1

公开(公告)日：1997-10-17

申请号：SG1996000246

申请日：1992-05-20

Applicant: IBM

Inventor： COKER JONATHAN DARREL ,  DOLIVO FRANCOIS BERNARD ,  GALBRAITH RICHARD LEO ,  SCHOTT WOLFGANG HANS ,  ZIPEROVICH PABLO ALEJANDRO

IPC: G11B5/09 ,  G11B19/02 ,  G11B20/10 ,  G11B20/14 ,  H03H21/00 ,  H04B3/04 ,  H04L25/497

Abstract: A method and apparatus are provided for controlling a digital filter function included in a data path within gain and timing control loops of a PRML magnetic recording channel. The digital filter function is removed from the data path during an acquisition mode and the digital filter function is restored to the data path during a tracking mode. A predetermined gain and a quantized delay at a synchronization frequency are provided when switching from acquisition mode to tracking mode. A unity gain and a delay of an integer number of sample periods are provided at a synchronization frequency when switching from acquisition mode to tracking mode.