Abstract: A method for producing a LDPC encoded test pattern for media in a LDPC based drive system includes adding error detection code data to a predominantly zero bit test pattern and adding additional zero bits to produce a test pattern of a desirable length. The test pattern may then be scrambled to produce a desirable flaw detection test pattern. The flaw detection test pattern may then be encoding with an LDPC code, or other error correction code with minimal disturbance to the run length constraints of the data pattern, and written to a storage medium.

Abstract: Systems and methods for magnetoresistive asymmetry estimation may include, but are not limited to, operations for: receiving a magnetic read head transducer output; computing a mean value of the magnetic read head transducer output; computing a median value of the magnetic read head transducer output; and applying a correction coefficient to a magnetic read head detector input according to at least the mean value of the magnetic read head transducer output and the median value of the magnetic read head transducer output.

Abstract: Systems and method relating generally to data processing, and more particularly to systems and methods for encoding and decoding information. Some embodiments include one or both of a multi-algorithm data encoder circuit and/or a multi-algorithm data decoder circuit. In some cases, a first algorithm encoding is applied on a first section by section basis to a user data set yield an encoded portion; and a second algorithm encoding is applied on a second section by section basis to a data set derived from a subset of the encoded portion.

Abstract: A communication system and a noise predictive calibration method are disclosed. The communication system includes a decoder configured to decode an input signal, wherein the decoder produces one of: a converged data output when the decoder decodes the input signal successfully, and a non-converged data output when the decoder decodes the input signal unsuccessfully. The communication system also includes a convergence monitor configured to determine a calibration procedure based on at least one of: a number of times where the decoder decodes successfully, and a number of times where the decoder decodes unsuccessfully. A noise predictive calibration circuit is configured to utilize output produced by the decoder without qualification when the convergence monitor indicates utilization of a first calibration procedure.

Abstract: Systems and methods relating generally to data processing, and more particularly to systems and methods for encoding and decoding information. As an example, a method is discussed that includes: applying a first level encoding on a section by section basis to a first data portion to yield a first encoding data including a first encoded portion; applying a second level encoding on a section by section basis to the first encoded portion to yield a first parity set; applying a third level encoding on a section by section basis to a combination of the first data portion, the second data portion, and a portion derived from the first encoded portion to yield a second encoding data.

Abstract: A communication system and a noise predictive calibration method are disclosed. The communication system includes a decoder configured to decode an input signal, wherein the decoder produces one of: a converged data output when the decoder decodes the input signal successfully, and a non-converged data output when the decoder decodes the input signal unsuccessfully. The communication system also includes a convergence monitor configured to determine a calibration procedure based on at least one of: a number of times where the decoder decodes successfully, and a number of times where the decoder decodes unsuccessfully. A noise predictive calibration circuit is configured to utilize output produced by the decoder without qualification when the convergence monitor indicates utilization of a first calibration procedure.

Abstract: Systems, methods, devices, circuits for data processing, and more particularly to systems and methods for determining a down track distance between two or more read heads on a read/write head assembly.

Abstract: Systems, methods, devices, circuits for data processing, and more particularly to systems and methods for determining a down track distance between two or more read heads on a read/write head assembly.

Abstract: Systems and methods for magnetoresistive asymmetry estimation may include, but are not limited to, operations for: receiving a magnetic read head transducer output; computing a mean value of the magnetic read head transducer output; computing a median value of the magnetic read head transducer output; and applying a correction coefficient to a magnetic read head detector input according to at least the mean value of the magnetic read head transducer output and the median value of the magnetic read head transducer output.

Abstract: An apparatus for reading data includes an array of analog inputs operable to receive analog signals retrieved from a magnetic storage medium, wherein the analog inputs correspond to multiple data tracks on the magnetic storage medium, and wherein the number of analog inputs in the array of analog inputs is greater than the number of data tracks being read, at least one joint equalizer operable to filter the analog inputs to yield an equalized output for each of the data tracks being read, and at least one data detector operable to apply a detection algorithm to the equalized output from the joint equalizer to yield detected values for each of the data tracks being read.

Abstract: A magnetic recording system includes an array of analog inputs operable to receive analog signals retrieved from a magnetic storage medium, a modulator operable to combine the analog signals to yield a frequency division multiplexed signal, a demodulator operable to yield a plurality of demodulated signals from the frequency division multiplexed signal corresponding to each channel of the array, and a joint equalizer operable to filter the plurality of demodulated signals to yield an equalized output.

Abstract: Various approaches, methods, systems, circuits and devices for channel bit density estimation.

Abstract: A catheter having an elongated shaft and a balloon on a distal shaft section, the elongated shaft comprising an outer tubular member, and an inner tubular member which has a bonded portion along which an outer surface of the inner tubular member is bonded to an inner surface of the outer tubular member. The inner tubular member has a proximal portion proximal to the bonded portion, and a distal portion distal to the bonded portion with higher axial compression stiffness and column strength than the proximal portion thereof. The catheter has improved trackability, axial collapse resistance, pushability, and crossability, for improved ability to position the balloon at a desired location in a patient's body lumen.

Abstract: An apparatus for reading data includes an array of analog inputs operable to receive analog signals retrieved from a magnetic storage medium, wherein the analog inputs correspond to multiple data tracks on the magnetic storage medium, and wherein the number of analog inputs in the array of analog inputs is greater than the number of data tracks being read, at least one joint equalizer operable to filter the analog inputs to yield an equalized output for each of the data tracks being read, and at least one data detector operable to apply a detection algorithm to the equalized output from the joint equalizer to yield detected values for each of the data tracks being read.

Abstract: Servo channel noise limits are defined through Viterbi decisions based on servo gate signals. Y values are used to produce a first Viterbi decision at each servo gate. Viterbi decisions and Y values are used to produce ideal Y values. Y values and ideal Y values are used to produce an error value which is adjusted by a noise factor based on estimated channel characteristics. The noise value is combined with Y values and used to produce a second Viterbi decision at each servo gate.

Abstract: A catheter having an elongated shaft and a balloon on a distal shaft section, the elongated shaft comprising an outer tubular member, and an inner tubular member which has a bonded portion along which an outer surface of the inner tubular member is bonded to an inner surface of the outer tubular member. The inner tubular member has a proximal portion proximal to the bonded portion, and a distal portion distal to the bonded portion with higher axial compression stiffness and column strength than the proximal portion thereof. The catheter has improved trackability, axial collapse resistance, pushability, and crossability, for improved ability to position the balloon at a desired location in a patient's body lumen.

Abstract: A thermal energy store comprising a chamber having a gas inlet and a gas outlet and a plurality of successive, downstream, gas permeable thermal storage layers disposed between them, each layer comprising gas permeable thermal storage media, the store being configured for gas flow from the gas inlet to gas outlet through the layers for transfer of thermal energy to or from the thermal storage media, wherein at least one of the layers is a valved layer provided with at least one valve operable selectively to allow or prevent at least some gas flow through that layer via the valve so as to bypass the thermal storage media. A control system may selectively alter the flow path of the gas flowing from inlet to outlet in response to the progress of a thermal front, so as to bypass thermal storage layers upstream of the thermal front, where transfer is complete, or downstream thereof, where transfer is minimal.

Abstract: Systems and method relating generally to data processing, and more particularly to systems and methods for encoding and decoding information.

Abstract: A system and method for power management in a hard disk drive (HDD) assembly incorporating two or more read sensors includes directing a read/write head to follow a track; depowering one or more read sensors and readpath circuits associated with the read sensors; reading an analog readback signal through the first read sensor; processing the signal through an analog front-end to generate an input signal; sampling the input signal through an analog to digital converter at a first frequency to generate a first sampling signal; sampling the input signal through a second analog to digital converter at a second frequency to generate a second sampling signal; and generating a digital output signal from either or both sampling signals at a third sampling frequency through a digital signal processor. The method may additionally comprise adjusting a sampling frequency when power level reaches a threshold.

Abstract: Systems and method relating generally to data processing, and more particularly to systems and methods for tone reduction in relation to data transmission. In one case, a data processing system is disclosed that includes: a two stage tone reduction circuit including a first stage circuit and a second stage circuit; and a polarity change circuit operable to change a polarity of the second stage output to yield a tone reduction output.