The assignee for this patent application is
Reporters obtained the following quote from the background information supplied by the inventors: "A read channel integrated circuit (IC) is one of the core electronic components in a modern hard disk drive. In a magnetic recording system, for example, a read channel converts and encodes data to enable magnetic recording heads to write data to a magnetic medium and to then read back the data accurately. The magnetic media in a magnetic recording system have a number of tracks and each track comprises 'read' sectors, with 'servo' sectors embedded between the read sectors. The information recorded in the servo sectors helps to position a magnetic recording head so that the user information stored in the read sectors can be retrieved properly.
"The servo and read sectors both typically begin with the same known preamble pattern. The read preamble is followed by a read address mark and encoded user data. The servo preamble is followed by a servo address mark and various servo data, including a repeatable run out (RRO) data field that compensates for known errors due to inaccurate spindle centers on the disks. The RRO data field typically comprises an RRO synchronization pattern that is often referred to as an RRO address mark (RROAM), followed by additional RRO data.
"When the magnetic hard disk is not spinning exactly at the center, the magnetic recording head will observe an elliptical track rather than a circular track. Flaw scan circuits are typically used to determine the quality of the RRO data that is read from the magnetic media. Existing flaw scan circuits identify low quality samples entering a data detector in a magnetic recording system and set a flag when the number of low quality samples exceeds a specified threshold. The flaw scan circuit will typically begin counting the number of low quality samples after detecting the RRO address mark. When the RRO address mark is missed and a false RRO address mark pattern is later detected due to noise, however, the flaw scan circuit may not properly count the low quality samples. For example, if the false RRO address mark is found towards the end of a servo processing gate, an insufficient number of low quality samples will be captured to set the flag.
"A need therefore exists for improved flaw scan circuits for repeatable run out data."
In addition to obtaining background information on this patent application, VerticalNews editors also obtained the inventor's summary information for this patent application: "Illustrative embodiments of the invention provide improved flaw scan circuits for repeatable run out data. According to one embodiment of the invention, RRO (repeatable run out) data is processed by counting a number of RRO data bits detected in a servo sector; and setting an RRO flaw flag if at least a specified number of RRO data bits is not detected in the server sector.
"In another embodiment, the RRO flaw flag can also be set by detecting an RRO address mark in the servo sector; counting a number of samples in the servo sector after the RRO address mark that do not satisfy a quality threshold; and setting the RRO flaw flag when the counted number of samples that that do not satisfy the quality threshold exceeds a specified flaw threshold.
"A more complete understanding of embodiments of the present invention will be obtained by reference to the following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
"FIG. 1 illustrates a typical track format for recording servo sector information and read sector information on a magnetic medium;
"FIG. 2 illustrates a format for the servo sectors of FIG. 1;
"FIG. 3 illustrates a format for the RRO data field of FIG. 2;
"FIG. 4 is a block diagram illustrating a magnetic recording system in which embodiments of the present invention can be implemented;
"FIG. 5 illustrates a waveform comprising asynchronous sample points and interpolated sample points;
"FIG. 6 is a block diagram illustrating an embodiment of a flaw scan system; and
"FIG. 7 is a block diagram illustrating a flaw scan system according to one embodiment of the present invention."
For more information, see this patent application: Annampedu, Viswanath. Flaw Scan Circuit for Repeatable Run Out (Rro) Data. Filed
Keywords for this news article include:
Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC
Most Popular Stories
- Senate Dems Pull All-Nighter on Global Warming
- Why New Workers Can't Get Ahead
- myLINGO Translates Hollywood Films into Spanish
- Rand Paul Takes Pot Shot at Ted Cruz
- Obama Plugs ACA on Zach Galifianakis Show
- Snowden Urges Silicon Valley to Resist Internet Spying
- Toledo Jeep Plant Hiring Part-Timers
- OECD Forecasts Slowdown in Global Growth
- Miley Cyrus Performs in Undies After Costume Goes Missing
- Dianne Feinstein Accuses CIA of Spying on Congress