Patent ID: 7199956

Claim:
A synchronous sampling data detection circuit for a disk drive, wherein the disk drive includes a head and a reference disk, the reference disk includes a printed reference pattern transferred by magnetic printing, the printed reference pattern includes embedded servo information, and the disk drive positions the head using the embedded servo information to self-write servo patterns on the reference disk, the data detection circuit comprising: a digital sampler that synchronously samples an analog readback signal at a sample rate and generates digital samples representing the analog readback signal, wherein the head provides the analog readback signal in response to reading the printed reference pattern, the analog readback signal includes a fundamental harmonic and a higher harmonic, and the fundamental and higher harmonics represent the embedded servo information; a harmonic signal processor that receives the digital samples and generates recovered samples representing the fundamental and higher harmonics; and a control loop that extracts the embedded servo information from the recovered samples.