Abstract: 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.

Abstract: An embedded disk controller comprises a main processor in communication with a first bus. A second processor is in communication with a second bus. An external bus controller (EBC) is in communication with the first bus and in communication with external devices via an external bus interface. A history module is located in the embedded disk controller, communicates with the first bus and the second bus, and at least one of monitors transaction information of one of said external devices and masks information of one of said external devices via the EBC based on setup information, wherein the EBC and the history module are located on at least on of an integrated circuit (IC) and a system on a chip (SOC) with the embedded disk controller.

Abstract: 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 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. The position error calculator is functionally coupled to the position error compensator having a single filter or more than one cascaded filters each having reduced input to output delay through use of an anticipation mode.

Abstract: A format for embedded servo track identification fields in rotating disk data storage units such as magnetic disk drives. The present invention uses the concept of tri-bits (i.e., three code bits per logical bit) to encode track identification information in servo wedges of embedded servo disk drive systems. More specifically, two particular sets (and their equivalents) of tri-bit codes have been discovered to have optimum characteristics for providing a phase coherent encoding of a Gray code that is simple to translate into straight binary code. The properties of such tri-bit encoding limit error propagation to a single bit, which allows for very reliable track identification during movement of a head transducer across tracks (i.e., "seeks"). A full range of Gray scale codes is available since more than two consecutive logical "0"s can be reliably decoded when encoded using such tri-bits.