Abstract: Apparatus and methods are disclosed for decoding data stored on a data storage medium. A disclosed decoding method and decoder include a radial incoherence (RI) detector that increases the probability of detecting RI and improves the decoding performance in terms of the bit error rate of the decoded signal. RI is detected by comparing an input signal to the decoder against a RI threshold value and generating a RI-type signal. The RI detector may include a filter for filtering out noise and error in the RI-type signal, an adaptive threshold unit that adjusts the RI threshold value based upon the RI-type signal, a transition-based threshold unit that adjusts the RI threshold value based upon each transition in the input signal, or a path-based threshold unit that adjusts the RI threshold value based upon a best surviving path corresponding to the input signal, in combination or alone.

Abstract: A transceiver includes a transmitter and a receiver. The transmitter includes an ECC encoder and a data frame generator. The ECC encoder is configured to generate an ECC parity from user data and at least one bit from a syncmark. The data frame generator is configured to generate a data frame for transmission from the syncmark, the user data, and the ECC parity. The receiver includes a detector, an inverter, and a decoder. The detector is configured to detect a received syncmark in a received data frame. The received data frame includes the received syncmark, received user data, and received ECC parity. The inverter is configured to selectively invert a sequence. The sequence includes the received user data, the received ECC parity, and at least one bit from the received syncmark. The decoder is configured to decode one of the sequence or the inverted sequence.

Abstract: A system including a padding field generator and an encoder. The padding field generator is configured to generate a first padding field for a frame. The frame includes (i) a preamble field, (ii) a syncmark field, and (iii) a data field. The first padding field is located between (i) the preamble field and (ii) the syncmark field. The preamble field, the first padding field, and the syncmark field precede the data field. The encoder is configured to encode, using an error-correcting code, (i) the first padding field, (ii) the syncmark field, and (iii) the data field; and to generate, based on the encoding performed using the error-correcting code, one or more parity bits. The one or more parity bits are stored in a parity field of the frame. The parity field is located subsequent to the data field in the frame.

Abstract: Apparatus and methods are disclosed for decoding data stored on a data storage medium. A disclosed decoding method and decoder include a radial incoherence (RI) detector that increases the probability of detecting RI and improves the decoding performance in terms of the bit error rate of the decoded signal. RI is detected by comparing an input signal to the decoder against a RI threshold value and generating a RI-type signal. The RI detector may include a filter for filtering out noise and error in the RI-type signal, an adaptive threshold unit that adjusts the RI threshold value based upon the RI-type signal, a transition-based threshold unit that adjusts the RI threshold value based upon each transition in the input signal, or a path-based threshold unit that adjusts the RI threshold value based upon a best surviving path corresponding to the input signal, in combination or alone.

Abstract: Apparatus and methods are disclosed for decoding data stored on a data storage medium. A disclosed decoding method and decoder include a radial incoherence (RI) detector that increases the probability of detecting RI and improves the decoding performance in terms of the bit error rate of the decoded signal. RI is detected by comparing an input signal to the decoder against a RI threshold value and generating a RI-type signal. The RI detector may include a filter for filtering out noise and error in the RI-type signal, an adaptive threshold unit that adjusts the RI threshold value based upon the RI-type signal, a transition-based threshold unit that adjusts the RI threshold value based upon each transition in the input signal, or a path-based threshold unit that adjusts the RI threshold value based upon a best surviving path corresponding to the input signal, in combination or alone.

Abstract: A method for generating a data frame for data transmission includes using a processor to generate a first padding field. The method also includes using the processor to generate one or more parity bits by encoding an input comprising the first padding field, a syncmark and data to be transmitted. The method also includes using the processor to add the one or more parity bits to the data frame. The method also includes using the processor to add a second padding field after the one or more parity bits.

Abstract: Methods, apparatuses, and systems implementing analog techniques to decode signals extracted from servo wedges of computer-readable storage media. A digital representation of at least a portion of a repeatable runout (RRO) signal derived from an analog signal read from a computer-readable storage medium is obtained. An estimate of a magnitude of the RRO signal is determined based on the digital representation. An error signal is generated to represent a difference between the estimate of the magnitude and a specified level of the magnitude of the RRO signal, and a gain value is configured, based on the error signal, for decoding a signal from the computer-readable storage medium.

Abstract: Methods, apparatuses, and systems describing digital techniques to decode signals extracted from computer-readable storage media include, in at least some implementations, a method including receiving a digital signal representing at least a portion of an analog signal from a computer-readable storage medium, the analog signal including a repeatable runout (RRO) signal component, determining an estimate of a magnitude of at least a portion of the RRO signal component, and decoding the digital signal at least in part by configuring a gain target value based on the estimate of the magnitude. In some implementations, the method includes causing the gain target value to change from a predetermined default gain target value to the configured gain target value based on the estimate of the magnitude.

Abstract: Apparatus and methods are disclosed for decoding data stored on a data storage medium. A disclosed decoding method and decoder include a radial incoherence (RI) detector that increases the probability of detecting RI and improves the decoding performance in terms of the bit error rate of the decoded signal. RI is detected by comparing an input signal to the decoder against a RI threshold value and generating a RI-type signal. The RI detector may include a filter for filtering out noise and error in the RI-type signal, an adaptive threshold unit that adjusts the RI threshold value based upon the RI-type signal, a transition-based threshold unit that adjusts the RI threshold value based upon each transition in the input signal, or a path-based threshold unit that adjusts the RI threshold value based upon a best surviving path corresponding to the input signal, in combination or alone.

Abstract: Methods, apparatuses, and systems implementing analog techniques to decode signals extracted from servo wedges of computer-readable storage media. A digital signal representing a repeatable runout (RRO) signal included in an analog signal of a computer-readable storage medium is obtained. The RRO signal includes a preamble that represents a magnitude of the RRO signal, and data. The digital signal includes a digital representation of the preamble. An estimate of the magnitude of the RRO signal is determined based on the digital representation. The estimate is compared with a specified level to generate an error signal based on a difference between the two. The provision of the error signal, for application to a subsequent RRO signal of the computer-readable storage medium, is delayed. The RRO signal is amplified prior to being represented as the digital signal to match a value established to decode the RRO signal.

Abstract: Apparatus and methods are disclosed for decoding data stored on a data storage medium. A disclosed decoding method and decoder include a radial incoherence (RI) detector that increases the probability of detecting RI and improves the decoding performance in terms of the bit error rate of the decoded signal. RI is detected by comparing an input signal to the decoder against a RI threshold value and generating a RI-type signal. The RI detector may include a filter for filtering out noise and error in the RI-type signal, an adaptive threshold unit that adjusts the RI threshold value based upon the RI-type signal, a transition-based threshold unit that adjusts the RI threshold value based upon each transition in the input signal, or a path-based threshold unit that adjusts the RI threshold value based upon a best surviving path corresponding to the input signal, in combination or alone.

Abstract: Methods, apparatuses, and systems describing digital techniques to decode signals extracted from computer-readable storage media. A digital signal that includes a digital representation of a repeatable runout signal having a magnitude and included in an analog signal is obtained. An estimate of the magnitude of the RRO signal based on the digital signal is determined. The estimate is provided for decoding the digital signal to extract the included data by adapting a detector gain target in accordance with the estimate. The detector gain target is a function of a desired amplitude of the RRO signal.