Patent application number | Description | Published |
20080215893 | Multiple levels of guided scrambling - Multiple levels of guided scrambling. Selective scrambling is performed on user data (or any information) that is to be output. The selection of which scrambling is to be employed can be based on whether or not a baseline error constraint and/or randomness constraint is met. The writing of the scrambled user data can be performed in parallel with, during the same time period, and/or simultaneously with the determination of whether or not a baseline error constraint and/or randomness constraint is met. If the constraint is not met, the outputting and/or writing of the scrambled user data can be aborted mid-process. | 09-04-2008 |
20080240278 | JOINT DECODING OF ISI (INTER-SYMBOL INTERFERENCE) CHANNEL AND MODULATION CODES - Joint decoding of ISI (Inter-Symbol Interference) channel and modulation codes. A means is presented by which a single, combined ISI and modulation decoding module is operable to process a signal received from an ISI communication channel and directly to generate a soft estimate of information encoded therein. A single module, that employs a decoding transfer function that is substantially matched to the communication channel that introduces the ISI and the modulation encoding performed on the information before being launched into the ISI communication channel. This means is adaptable to a variety of modulation coding systems that are tailored to deal with communication systems that introduce ISI. Moreover, this means is extendable to communication systems employing an error correction code (ECC) such as Reed-Solomon (RS) coding as well as ECCs of an iterative nature such as LDPC (Low Density Parity Check) coding, turbo coding, and/or turbo trellis code modulation (TTCM) coding. | 10-02-2008 |
20080244356 | SUPER BLOCK ERROR CORRECTION CODE (ECC) ADAPTABLE TO COMMUNICATION SYSTEMS INCLUDING HARD DISK DRIVES (HDDs) AND OTHER MEMORY STORAGE DEVICES - Super block error correction code (ECC) adaptable to communication systems including hard disk drives (HDDs) and other memory storage devices. A means is presented by which a number of blocks of information can be organized, with a degree of ECC provided thereto, and transmitted via a signal into a communication channel. In some instances, the communication channel is coupled to a storage media as in the context of an HDD, and information is written to and read from the storage media via this communication channel (e.g., “read channel”). This means is particularly well suited to applications that provide large amounts of data via any one transmission (e.g., DVR/PVR (Digital/Personal Video Recorder)). A redundant block is generated using the information of each of a number of information blocks thereby provided extra ECC on a large portion of data, and that redundant block also undergoes ECC encoding. | 10-02-2008 |
20080266693 | BASE LINE CONTROL ELECTRONICS ARCHITECTURE - A read channel in that reads data from a magnetic storage media. An analog signal produced by passing a read head over magnetic storage media is amplified to match the range of an analog to digital converter (ADC) range. A baseline adjustment is performed on the amplified analog signal to center the amplified analog signal to a midscale of the ADC, which may be based on an error feedback signal and/or a decision feedback signal. Read channel compensation may then be performed after the baseline adjustment has been applied. The read channel compensated analog signal is sampled with the ADC to produce a digital signal. This digital signal may be filtered and a bit sequence may then be detected from the filtered digital signal. The EFB signal and/or the DFB signal may be produced in the digital domain based on the digital signal and the detected bit sequences. | 10-30-2008 |
20080266694 | DISK CLOCK SYSTEM WITH UP-SAMPLER TO GENERATE FREQUENCY OFFSET - A system reads data from a magnetic storage media. A read head reads data from the magnetic storage media and produce an analog signal. A variable gain amplifier amplifies the analog signal. An offset adjust module substantially centers the amplified analog signal to a midscale. A Magneto Resistive Asymmetry (MRA) collection module MRA corrects the amplified analog signal. A Continuous Time Filter (CTF) compensation module processes the amplified analog signal. An Analog to Digital Converter (ADC) samples the amplified analog signal based upon a control signal to produce a digital signal. A Disk Lock Clock (DLC) system produces the control signal to the ADC. The control signal is representative of a frequency offset caused by at least one servo wedge rate error. A Finite Impulse Response (FIR) filter module filters the digital signal. A sequence detector processes the digital signal and detects a bit sequence from the digital signal. | 10-30-2008 |
20080266702 | SYSTEM FOR MEASURING HEAD SPACING (FLY HEIGHT) IN A DISK DRIVE - A system and method to measure capacitance between a recording media, such as but not limited to a magnetic disk in a hard disk drive, and a read-write (RW) head is provided. Once the capacitance has been measured, the head spacing may be determined between the RW head and the recording media. This capacitance between the RW head and the recording media, is a function of geometry and the dielectric constant associated with the head spacing. Because the dielectric constant and the area of the RW head and disk are substantially constant, the only change is the separation, i.e. head spacing. Thus, the capacitance becomes a function of the head spacing or fly height. | 10-30-2008 |
20080267323 | SLIDING BLOCK TRACEBACK DECODING OF BLOCK CODES - Sliding block traceback decoding of block codes. Block by block basis decoding is performed in which a single block, and its corresponding overlap portion, are processed during a given time. The traceback saves a record of decision (e.g., among possible trellis branches between various trellis stages) and constructs only the surviving paths through each individual block. Since only one block (by also employing its corresponding overlap portion) is decoded per time, the traceback through the coded block signal is short. One block of the coded block signal is decoded at a time, and certain resulting information (e.g., bit estimates and/or states) of a first decoded block can be leveraged when decoding a second/adjacent block. | 10-30-2008 |
20080294840 | READ/WRITE CHANNEL CODING AND METHODS FOR USE THEREWITH - A write channel includes a pre-encoding module that encodes write data to produce pre-encoded data. An error correcting code (ECC) module generates ECC data based on the pre-encoded data. A post-encoding module encodes the ECC data to produce post-encoded data. A combining module combines the pre-encoded data and the post-encoded data for writing to the storage medium. | 11-27-2008 |
20090207517 | "Flat analog" AFE coupled with an all digital architecture compensation read channel - Reading data from a magnetic storage media with an analog front end (AFE) coupled to an all digital read channel compensation architecture. A read head passes over magnetic storage media to produce an analog signal. The analog signal is amplified such that the range of the amplified analog signal substantial matches a range of the analog to digital converter (ADC) used to sample the analog signal. A baseline adjust is performed on the amplified analog signal to center the amplified analog signal to a midscale of the ADC. The amplified analog signal may be sampled where the sampling is data frequency locked by a data lock clock (DLC) tracking module. A digital signal may then be produced from the amplified analog signal where this signal is read channel compensated in the digital domain to produce a digital signal which is then processed with a sequence detector. | 08-20-2009 |
20100046107 | MAGNETIC DISK DRIVE, SERVO WRITER, SELF-SERVO WRITER AND METHODS FOR USE THEREWITH - A servo writer includes a servo data generation module that generates servo data corresponding to a plurality of servo wedges and a plurality of tracks of a disk, the servo data including track identification data that is repetition coded. A servo write module writes the servo data on the disk. | 02-25-2010 |
20100091398 | Disk clock system with up-sampler to generate frequency offset - A system reads data from a magnetic storage media. A read head reads data from the magnetic storage media and produce an analog signal. A variable gain amplifier amplifies the analog signal. An offset adjust module substantially centers the amplified analog signal to a midscale. A Magneto Resistive Asymmetry (MRA) correction module MRA corrects the amplified analog signal. A Continuous Time Filter (CTF) compensation module processes the amplified analog signal. An Analog to Digital Converter (ADC) samples the amplified analog signal based upon a control signal to produce a digital signal. A Disk Lock Clock (DLC) system produces the control signal to the ADC. The control signal is representative of a frequency offset caused by at least one servo wedge rate error. A Finite Impulse Response (FIR) filter module filters the digital signal. A sequence detector processes the digital signal and detects a bit sequence from the digital signal. | 04-15-2010 |
20110283167 | Super block error correction code (ECC) adaptable to communication systems including hard disk drives (HDDs) and other memory storage devices - Super block error correction code (ECC) adaptable to communication systems including hard disk drives (HDDs) and other memory storage devices. A means is presented by which a number of blocks of information can be organized, with a degree of ECC provided thereto, and transmitted via a signal into a communication channel. In some instances, the communication channel is coupled to a storage media as in the context of an HDD, and information is written to and read from the storage media via this communication channel (e.g., “read channel”). This means is particularly well suited to applications that provide large amounts of data via any one transmission (e.g., DVR/PVR (Digital/Personal Video Recorder)). A redundant block is generated using the information of each of a number of information blocks thereby provided extra ECC on a large portion of data, and that redundant block also undergoes ECC encoding. | 11-17-2011 |