Servo PLO Out of Sync Detector
Original Publication Date: 1980-Dec-01
Included in the Prior Art Database: 2005-Feb-13
The servo channel phase-locked oscillator (PLO) for a rigid disk file provides a reference clock signal, synchronized with the disk rotational frequency. An out-of-sync condition must be detected immediately and a resync process promptly initiated to resynchronize the servo PLO frequency with the disk rotational frequency. Though important to identify a true out-of-sync condition, it is equally important to prevent an out-of-sync indication by a false signal, such as electrical noise.