Research On Servo Signal Reading System Of Microdrive

Seeking and tracking the given tracks in a magnetic disk drive are of critical importance for retrieving user data. The capacity of magnetic disk drive has increased significantly in recent years, while the size of disk drive is keeping smaller and smaller. As track densities have increased, so have the demands on the servo system to reliably follow the data tracks. Precise tracking of the data requires an exact radial position estimate of the readback head location. This estimate is typically called the Position Error Signal (PES). The derivation of the PES from the readback signal using a previously written pattern of magnetic transition (the servo pattern) is PES generation.Getting servo signal on the platter correctly is one of the servo channel functions, and then the servo system could know the head position and seek the track depending on the PES. The processing methods of the read back servo signal are analyzed, and a firmware of microdrive servo system on a channel IC has been developed. The firmware could control the chip to complete servo signal processing, and meet requirement of servo platform.The read/write channel is embedded in a SoC chip with ARM966E-S core. Aiming at special hardware architecture, a suitable scheme of servo platform has been designed. Based on the analysis of key servo modules, the overall system process has been developed; the problem of porting the embedded real time operation system has been discussed and some necessary steps have been given. Finally some test has been shown.After the research on experimentation, the system could get the servo signal, such as Gray code and burst signal, and deduce the position error signal. The results truly reflect the real work condition of the microdrive.