Marvell International Limited

Raymond A Sandoval

Michael R Spaur

A servo controller includes a first device that determines an adjusted servo-to-servo skew value. A servo field timer increments a timer value between consecutive servo fields, receives the adjusted servo-to-servo skew value, and adjusts an incremented timer value between the consecutive servo fields based on the adjusted servo-to-servo skew value.

Method and system for automatic time base adjustment for disk drive servo controllers

A track follow controller includes a burst selector selecting at least one burst pair based on burst pair selection data. A linear position calculator calculates a primary head position and a secondary head position based on the at least one burst pair, and calculates a head linear position based on the primary head position and the secondary head position.

Method and system for head position control in embedded disk drive controllers

A system and method for a servo controller (SC) used in an embedded disk controller for adjusting stored servo skew values based on measured skew values is provided. The system includes, a servo timing controller, wherein the servo timing controller includes a first register that stores measured servo skew values at a given time; a first set of registers that receive stored skew values and the measured skew values; and firmware that adjusts the skew values based on the measured skew values measured by a reference timer. The process includes, measuring actual skew values during a head change in a read operation; comparing the measured skew values with the stored skew values; adjusting the skew value based on the comparison; and adjusting a servo field timer based on the adjusted skew value.

A position error calculator for an embedded disk controller including a burst selector that selects a burst pair based on a burst pair format. The burst pair format includes at least a first burst pair format that includes x bursts and a second burst pair format that includes y bursts and x is not equal to y. A linear position calculator calculates head linear position based on the burst pair format.

A servo controller for an embedded disk controller comprises a read channel interface that includes a programmable control logic that receives a servo field detected signal from a module that detects a servo field start bit. A memory in the read channel interface is enabled by the programmable control logic for receiving servo field data from a read channel device, wherein the programmable control logic is configured to operate in a first mode and a second mode allowing the servo controller to process servo data from the read channel device. The servo controller processes the servo data using first and second data widths during the first and second modes, respectively.

Method and system for collecting servo field data from programmable devices in embedded disk controllers

A track follow controller ('TFC') in an embedded disk controller is provided. The TFC includes, a position error calculator that determines a linear position of a head based on burst format and determines a position error based on the linear position and a target position; and a position error output compensator that receives a position error signal from the position error calculator and filters the position error signal. The burst format includes at least a first burst pair format that includes x bursts and a second burst pair format that includes y bursts, where x is unequal to y. The position error calculator includes a burst selector that can select a burst pair; a linear position calculator that calculates head linear position based on burst pair format; and an error calculator that determines the position error based on the linear position and target position.

A system for collecting servo field data from programmable devices in embedded disk controllers. The system includes a servo controller with a read channel interface. The read channel interface includes a programmable control logic that receives a servo field detected signal from a module that detects a servo field start bit; and a register in the read channel interface that is enabled by the programmable control logic for receiving servo field data from a read channel device. The programmable control logic is configured to operate both in a two wire mode and in a three wire mode allowing the servo controller to process servo data from the read channel device.

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Aliso Viejo, CA, United States of America

Raymond A Sandoval