A CIRCUIT FOR SELF-WRITING SERVO AND CLOCK FIELDS ON A DISC DRIVE

摘要

A disc drive (100) with an information portion previously written on a rotatable disc surface (106), a servo write clock generator phase lock loop circuit (168) controlling timing for writing a reference mark to the rotatable disc surface (106) in substantial time alignment and phase and frequentcy coherent with the information portion previously written to the rotatable disc surface (106), a servo write clock generator phase lock loop circuit (168) controlling timing for writing the reference mark, a pulse detector circuit (174) for creating logic level signals from the reference mark, a pattern generator (176) for generating reference mark write signals from the logic level signals, a memory buffer (182) for storing radial position correction tables and values for writing the reference mark, and a self-servo control and sequencing circuit (180) synchronizing timing signals for writing the reference mark to rotatable disc surface (106) of disc drive (100).