Error Detection For Synchronization Control Patents (Class 714/798)
  • Patent number: 6434146
    Abstract: A system and method for demultiplexing and distributing transport packets, such as MPEG-2 transport packets, by generating and associating a locally-generated header with each of the transport packets to create a self-contained modified packet which incorporates essential distribution information therein. The method for enhancing transport packet demultiplexing and distribution in a digital transport demultiplexing system that inputs a stream of digital multimedia transport packets is provided. Each of the transport packets includes a packet identifier (PID) to identify the digital program or elementary stream to which it corresponds. Local packet information is generated for each of the transport packets, which is used in identifying and distributing the transport packets. A local header is created that includes the generated local packet information, and the local header is linked to its corresponding transport packet to create a modified transport packet.
    Type: Grant
    Filed: December 4, 1998
    Date of Patent: August 13, 2002
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Alek Movshovich, Robert H. Hoem, Niranjan A. Puttaswamy, Brian Lai
  • Patent number: 6434512
    Abstract: A diagnostics/prognostics system and related method for collecting and processing data relating to a plurality of subsystems of a dynamic system includes a plurality of sensors, each sensor gathering data and generating a data signal indicative of the health of a corresponding one of the subsystems. In addition, the diagnostics/prognostics system includes a plurality of subsystem modules coupled to corresponding ones of the sensors for generating a subsystem health signal in response to corresponding ones of the data signals. Further, a master diagnostics module is coupled to the subsystems to generate an overall system health signal in response to the subsystem health signals. Preferably, the master diagnostics module includes a memory having an embedded model to facilitate generating the overall system health signal and a related trend analysis.
    Type: Grant
    Filed: September 30, 1999
    Date of Patent: August 13, 2002
    Assignee: Reliance Electric Technologies, LLC
    Inventor: Frederick M. Discenzo
  • Publication number: 20020108091
    Abstract: Systems, methods, and computer program products for deleting objects from device stores without deleting corresponding objects from one or more synchronization partners, A device has a device sync module for each synchronization partner and each device sync module maintains tracking data. Alternatively, a single device sync module manages the tracking data of each synchronization partner. When an object does not meet parameters of a synchronization filter, a soft delete request is made to the wireless device. A sync manager receives the soft delete request and determines from the other device sync modules that have registered with the sync manager whether they continue to synchronize the object. If none of the other device sync modules protest, the object is deleted. If one of the device sync modules objects to the delete request, then the delete is denied. The tracking data for all of the device sync modules is appropriately modified.
    Type: Application
    Filed: February 2, 2001
    Publication date: August 8, 2002
    Inventors: Stephen D. Flanagin, Greg S. Friedman
  • Patent number: 6427221
    Abstract: A rolling mill system uses a number of autonomous control units, each associated with one piece of equipment of the rolling mill system. The autonomious control units include data indicating not only their constraints of operation, but also reflecting the constraints of operation of machines to which they are attached and with which they share common operating parameters. An autonomous control unit associated with a machine having operating parameters in common with another machine of the rolling mill system adopts the intersection of the ranges of the machine constraints of the two machines. Machine constraints are preserved to the extent possible as ranges, so as to permit flexibility in selecting and seeking goals by the individual autonomous control units.
    Type: Grant
    Filed: April 12, 1999
    Date of Patent: July 30, 2002
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Francisco P. Maturana, Rebecca J. Herr, David A. Vasko, Joseph A. Lenner
  • Publication number: 20020078420
    Abstract: In one embodiment, an integrated circuit provides a test access port that communicates with scan chain registers in a processor core. The integrated circuit synchronizes data transferred between a debug controller that operates under control of a test clock (TCK) and the processor core that operates under control of a processor clock (CLK).
    Type: Application
    Filed: December 15, 2000
    Publication date: June 20, 2002
    Inventors: Charles P. Roth, Ravi P. Singh, Ravi Kolagotla, Tien Dinh
  • Publication number: 20020069390
    Abstract: In a data processor, a pickup head reads the data from a memory medium. Such data transferred in a plurality of parallel bits in synchronization with the clock signal to a controller unit from a read channel unit. The controller unit detects the predetermined mark for detecting synchronization included in the data in order to establish the synchronization of a series of data to be received from the read channel unit in order to demodulate the data other than the predetermined mark for detecting synchronization. The mark detecting unit in the controller unit detects the predetermined mark for detecting synchronization from the parallel data received with the shift register.
    Type: Application
    Filed: April 25, 2001
    Publication date: June 6, 2002
    Applicant: Fujitsu Limited
    Inventor: Masashi Yamawaki
  • Patent number: 6397369
    Abstract: A device using information about the extent of errors in a signal is shown. The device includes an input signal containing at least one constraint and any errors introduced into the input signal during transmission and/or sensing. A detector receives and is responsive to the input signal for generating an error signal containing information about the extent of error and for extracting an information signal from the input signal as an output signal. A control device is operatively coupled to the detector for receiving and responding to the error signal containing information about the extent of errors for generating a control signal used to reduce the extent of errors in the input signal based on information about the extent of errors contained in the error signal. A method for using information about the extent of errors is shown.
    Type: Grant
    Filed: November 6, 1998
    Date of Patent: May 28, 2002
    Assignee: Acorn Technologies, Inc.
    Inventors: Alvin M. Despain, R. Stockton Gaines
  • Patent number: 6385745
    Abstract: A circuit comprising a receiver configured to receive a first signal having a first phase, a second signal having a second phase opposite the first phase and an output configured to present either the first or second signals. A state machine may be configured to receive the output of the receiver circuit and to provide a control signal configured to select the first or second signals.
    Type: Grant
    Filed: June 30, 1997
    Date of Patent: May 7, 2002
    Assignee: Cypress Semiconductor Corp.
    Inventor: Edward L. Grivna
  • Publication number: 20020049954
    Abstract: Data synchronization detection means 3 is provided between data identification means 1 and code demodulation means 6 of the data reproduction system, which performs data synchronization detection using the code-modulated data itself; a specified bit pattern generated in the data codeword is calculated in each phase (bit), using a specified bit sequence pattern that is not generated in a specified phase of the data codeword, by the conversion law during code modulation (or there is a specified bit sequence pattern that is generated only in a specified phase of the codeword); the positions of the data codeword partitions are thereby identified. Scrambling is then applied to the write data as required in order to ensure accurate synchronization detection. In addition, the data position is specified by detecting the pattern correlation between the PLO_SYNC section and GAP section.
    Type: Application
    Filed: August 16, 2001
    Publication date: April 25, 2002
    Inventors: Yoshiju Watanabe, Yasuyuki Ito
  • Patent number: 6377643
    Abstract: An apparatus for detecting a sync signal in a digital data record/replay device having a parallel clock generator, a parallel data generator, and a window unit comprises: a sync signal detector for comparing a pattern matching sync signal output from a sync pattern detector with an output signal of the window unit and detecting a sync signal according to clocks of the parallel clock generator; a latch unit for latching the sync signal detected by the sync signal detector and outputting the sync signal as a sync position signal according to clocks of the parallel clock generator; an identification error correction code (ID ECC) controller for generating an ID ECC control signal according to the sync position signal of the latch unit; an ID ECC decoder for decoding ID areas of parallel data generated by the parallel data generator; and a sync signal checking unit for outputting the sync position signal of the latch unit as a final sync signal and, when errors are detected as a result of the ID ECC decoding, sen
    Type: Grant
    Filed: January 8, 1999
    Date of Patent: April 23, 2002
    Assignee: LG Electronics, Inc.
    Inventors: Doo-Hee Lee, Tae-Kyoung Kwon
  • Patent number: 6366624
    Abstract: Methods and systems are provided for receiving a modulated signal including symbols representing both encoded and unencoded bits from a data (e.g., speech) frame where a received slot is first demodulated and the encoded bits are decoded. The decoded bits are then utilized to constrain demodulation during a second demodulation of a received slot. The encoded bit positions from the constrained second demodulation are, in turn, encoded to generate bit estimates for the received slot. This information is combined with the output of the constrained second demodulation for unencoded bits to provide a received data frame estimate which has been shown to have improved reliability for both encoded and unencoded bits. The methods and systems further provide for recursively repeating the demodulation and decoding steps until a counter expires or a desired reliability is obtained.
    Type: Grant
    Filed: November 30, 1998
    Date of Patent: April 2, 2002
    Assignee: Ericsson Inc.
    Inventors: Kumar Balachandran, Ali Khayrallah
  • Patent number: 6363514
    Abstract: A sound reproducing system that decodes audio data in a frame with which detection of a syncword fails, if a syncword included in a subsequent frame is detected, if correctness of bit stream information in the subsequent frame is proved, and if no CRC error is detected (when CRC is included). This makes it possible to solve a problem involved in a conventional system in that when a unit frame without an error check pattern is input and a synchronization detector produces a synchronization detection error signal, unpleasant sound interruption can take place even if the audio data is correct, because the correctness of the audio data cannot be checked, and hence the audio data cannot be decoded in this case.
    Type: Grant
    Filed: January 5, 1999
    Date of Patent: March 26, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takahiro Kawai, Chuya Hayashi
  • Patent number: 6357033
    Abstract: A communication processing control apparatus for controlling data transmission between an arithmetic processing control apparatus and a network includes first and second communication processing sections, and a data control section. The first and second communication processing sections are made duplex and inserted into a duplex data transmission route to perform the same processing. The data control section adds CRC data to input data, and outputs the data to the first and second communication processing sections, and simultaneously checks the CRC data contained in output data from the first and second communication processing sections to detect a fault in the first and second communication processing sections.
    Type: Grant
    Filed: March 4, 1999
    Date of Patent: March 12, 2002
    Assignee: NEC Corporation
    Inventor: Akira Jippo
  • Publication number: 20020007473
    Abstract: For the purpose of error masking, binary representations of parameter values are precoded at the transmitting end by a linear block code before transmission over a faulty channel, and the redundant information added in this way is not used at the receiving end for error detection within the binary parameter representations, but is utilized in the course of a parameter estimation to improve the quality of the estimated parameter values.
    Type: Application
    Filed: November 29, 2000
    Publication date: January 17, 2002
    Inventors: Stefan Heinen, Wen Xu
  • Patent number: 6334203
    Abstract: In an error detecting method and device for calculating a phase error in a PSK modulated signal having a predetermined modulation phase number, and so configured that a received phase of the modulated signal is mapped on a complex plane by allocating an inphase signal and a quadrature signal generated from the modulated signal as values of the axis of abscissas and the axis of ordinates, and a phase error between the received phase of the modulated signal thus mapped and a reference phase in each of a plurality of signal areas. The phase error between the received phase of the modulated signal mapped on the complex plane and a reference phase in each of the plurality of signal areas, is calculated as a distance between the mapped position of the modulated signal and a reference straight line, from at least one of the inphase signal and the quadrature signal, so as to obtain a plurality of phase errors.
    Type: Grant
    Filed: November 30, 1998
    Date of Patent: December 25, 2001
    Assignee: NEC Corporation
    Inventor: Osamu Inagawa
  • Patent number: 6321343
    Abstract: A maximum flight time measuring circuit constituted by a first delay circuit for delaying a system clock and controlling its delay time in accordance with a strobe clock from DIMMs and a delayline register circuit for storing a delayed state in the delay circuit, and a second delay circuit are provided. Contents of the delayline register circuit are input to the second delay circuit, which is controlled to generate the same delay as that of the first delay circuit. The output of the second delay circuit is supplied as a data fetch signal to a control buffer for receiving read data DQ from the DIMMs.
    Type: Grant
    Filed: October 27, 2000
    Date of Patent: November 20, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Haruki Toda
  • Patent number: 6289297
    Abstract: An adaptive region-based, multi-scale, motion compensated video compression algorithm design for transmission over hostile communication channels. The algorithm is embodied in a video encoder that extracts spatial information from video frames to create video regions that are then decomposed into sub-bands of different perceptual importance before being compressed and transmitted independently. The system further uses unequal error protection, prioritized transmission and reconstruction to guarantee a minimum spatial and temporal resolution at the receiver. In particular, the region segmented frames bound both spatial and temporal error propagation within frames. A connection-level inter-region statistical multiplexing scheme is also employed to ensure optimal utilization of reserved transmission bandwidth.
    Type: Grant
    Filed: October 9, 1998
    Date of Patent: September 11, 2001
    Assignee: Microsoft Corporation
    Inventor: Paramvir Bahl
  • Patent number: 6266201
    Abstract: In a data recording system utilizing multiple channels and data blocks wherein the data blocks are read subsequent to being written so as to check for errors, the data blocks are rewritten according to a method to provide for rewriting only the defective data blocks. The blocks may be rewritten on other than their original channels. Channels for rewriting are determined by selecting a channel with a highest current block number so that data is rewritten in a channel which has been able to write and verify the most of its original blocks. Error checking is continued in a channel even after finding of an error in that channel. Data blocks of the frames may be skewed between the channels at a beginning of the frame. A ring counter output is applied to break a deadlock where a block is continously rewritten on a failing channel.
    Type: Grant
    Filed: August 19, 1998
    Date of Patent: July 24, 2001
    Assignee: Tandberg Data Asa
    Inventors: Ole Christian Dahlerud, Rolf Jahren, Arne Adli
  • Patent number: 6249896
    Abstract: Synchronization (sync) marks on a digital-versatile disk (DVD) optical disk are initially detected and later used to adjust bit timing after jitter has occurred. Each DVD physical sector contains many sync marks in a predefined sequence. Each sync mark has a sync-code field that varies for the sync marks in a sector, and a fixed sync pattern that is constant for all sync marks. The first sync mark is detected at initialization by detecting a previous sequence of sync codes of sync marks that precede the first sync mark. The sequence is programmable so that one to seven sync marks are in the sequence searched for. Detection for sync marks with bit errors can still occur since a programmable number of bit errors are allowed in each sync code and in the fixed sync pattern. One of the sync codes can be missed in the sequence and detection still made, allowing tolerance of errors in the sync marks when longer sequences of sync codes are matched.
    Type: Grant
    Filed: February 17, 1999
    Date of Patent: June 19, 2001
    Assignee: LSI Logic Corporation
    Inventors: Son Hong Ho, Hung Cao Nguyen, Phuc Thanh Tran
  • Patent number: 6226768
    Abstract: A coded frame synchronization method for decoding coded information sent every frame includes the steps of: (a) receiving a coded frame having error detection or correction codes, each of which is provided every predetermined number of bits, error detection or correction codes being added to the coded frame in accordance with a predetermined pattern; (b) pulling the coded frame in synchronization by performing an error detection process every predetermined number of bits to be compared with results of the error detection process and thus detecting a phase of the error detection or correction codes; and (c) recognizing a leading end of the coded frame on the basis of the phase of the error detection or correction codes.
    Type: Grant
    Filed: April 28, 1998
    Date of Patent: May 1, 2001
    Assignee: Fujitsu Limited
    Inventors: Kaoru Chujo, Naoji Fujino, Toshiaki Nobumoto, Tomonobu Takashima, Noboru Kobayashi, Miki Murakawa, Toshiyuki Ohta
  • Patent number: 6223317
    Abstract: The present invention includes bit synchronizers and methods of synchronizing and calculating error. One method of synchronizing with a data signal in accordance with the present invention includes providing a data signal having a first portion and a second portion, generating a timing signal, first adjusting the timing signal during the first portion of the data signal, accumulating a history value during the first portion of the data signal, and second adjusting the timing signal during a second portion of the data signal using the history.
    Type: Grant
    Filed: February 28, 1998
    Date of Patent: April 24, 2001
    Assignee: Micron Technology, Inc.
    Inventors: George E. Pax, David K. Ovard
  • Patent number: 6195343
    Abstract: In base station side equipment, a control channel for transmitting control information and a communication channel for transmitting information to each mobile station are spread with different synchronizing codes before being superposed by operating a switch to switch the output of an adder over to the output of a synchronizing code generator. Further, a synchronizing code is periodically inserted in a signal by one symbol length and the signal is transmitted over the superposed channel. In a plurality of base station side equipment, moreover, the synchronizing code and its transmission period are equal and the transmission timing is asynchronous and independent.
    Type: Grant
    Filed: March 12, 1997
    Date of Patent: February 27, 2001
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Masatoshi Watanabe
  • Patent number: 6195784
    Abstract: The present invention relates to a circuit of reception of bits transmitted on an asynchronous signal, including a circuit for providing a clock reconstructed from the asynchronous signal, this clock being used to sample the asynchronous signal to form a synchronous output signal, and a reception error detection circuit. The reception error detection circuit includes an edge detector providing a detection pulse for each edge of predetermined direction of the asynchronous signal; and an alarm circuit activating an alarm signal when an edge of predetermined direction of the synchronous signal occurs outside a detection pulse.
    Type: Grant
    Filed: May 21, 1998
    Date of Patent: February 27, 2001
    Assignee: SGA-Thomson Microelectronics S.A.
    Inventor: Didier Belot
  • Patent number: 6195783
    Abstract: A process and apparatus for synchronizing the block counter of an RDS radio data receiver is described. According to the process, the bits stored in a 26-bit shift register, are cycled at least n times in said register, n being the number of allowable offset words, and the shift register content is X-OR gated with another offset word in a given sequence for each cycle. The gating result is received by a syndrome detection circuit, which triggers a sync pulse when the zero syndrome is detected, and the sync pulse resets the bit counter to zero and sets the block counter to the address counter status assigned to the offset word in the offset word generator.
    Type: Grant
    Filed: September 19, 1997
    Date of Patent: February 27, 2001
    Assignee: Blaupunkt-Werke GmbH
    Inventors: Detlev Nyenhuis, Wilhelm Hegeler
  • Patent number: 6163869
    Abstract: A method for repeating data transmitted incorrectly (ARQ) between subscribers having in each case at least one transmit section, and at least one receive section. A data stream at the transmitting subscriber's end is subdivided into data words having a predetermined length. The data stream is combined to form data words where the individual data words are temporarily stored in a transmit buffer. The individual data words are transmitted, if necessary via a transmit unit, and are received by the receiving subscriber, if necessary in a receive unit. After temporary storage in a receive buffer the received data word is output.
    Type: Grant
    Filed: April 17, 1998
    Date of Patent: December 19, 2000
    Assignee: Ericsson Austria Aktiengesellschaft
    Inventor: Peter Langmann
  • Patent number: 6148348
    Abstract: A bridge for a multi-processor system includes bus interfaces for connection to an I/O bus of a first processing set, an I/O bus of a second processing set and a device bus. The bridge also includes a memory subsystem and a bridge control mechanism. The bridge control mechanism is operable to monitor operation of the first and second processing sets in a combined, lockstep, operating mode and to be responsive to detection of a lockstep error to cause the bridge to be operable in an error mode in which write accesses initiated by the processor sets are buffered in a bridge buffer pending resolution of the error mode. A respective buffer region is provided for each processing set. In an initial error mode, any complete device write accesses initiated by the processing sets are stored in a posted write buffer. Where data is in transit through the bridge on entry to the error mode, the data is diverted to one or more disconnect registers.
    Type: Grant
    Filed: June 15, 1998
    Date of Patent: November 14, 2000
    Assignee: Sun Microsystems, Inc.
    Inventors: Paul J. Garnett, Stephen Rowlinson, Femi A. Oyelakin
  • Patent number: 6134698
    Abstract: An isochronous bus may includes a data signal, a data valid signal, a frame synch signal and a clock signal. The bandwidth of the data signal is partitioned into a plurality of frames. The frame rate may be selected based upon the sample rate of one of the isochronous devices connected to the isochronous bus or maybe some divisor of the data rate of the isochronous bus. Each frame is partitioned into a plurality of data channels. Each data channel transmits data from an isochronous device. A number of bit time slots are allocated to each data channel. The number of bit time slots allocated to each data channel varies based upon the sample rate of the device corresponding to the data channel. In one embodiment, each data channel is allocated more bit time slots than the nominal samples of its corresponding device. In this manner, any drift of the sample clock may be accommodated. A data valid signal is transmitted synchronous to the data signal and the clock signal.
    Type: Grant
    Filed: June 17, 1998
    Date of Patent: October 17, 2000
    Assignee: Advanced Micro Devices, Inc.
    Inventor: Dale E. Gulick
  • Patent number: 6111924
    Abstract: A de-framer (72) in a communications gateway (22) translates videoconferencing information from a circuit-switched format to a packet-switched format. A demultiplexor (78) extracts a bitstream containing video information that includes error-correction-code fields disposed at predetermined locations with respect to synchronization bits spaced by a synchronization interval and forming a predetermined synchronization sequence. A frame checker (88) for checking the error-correction code finds codeword boundaries by comparing the predetermined synchronization sequence with sequences of synchronization-interval-spaced video-bitstream bits until it finds a match. To do so, the frame checker (88) takes a group of video-bitstream words offset from each other by the synchronization interval. It compares each word in the group with a respective synchronization word consisting of a word-width replication of a respective synchronization bit.
    Type: Grant
    Filed: February 3, 1998
    Date of Patent: August 29, 2000
    Assignee: VideoServer, Inc.
    Inventor: Brittain S. McKinley
  • Patent number: 6088828
    Abstract: In order to find the position of the boundary between transmitted codewords, in a receiver a reliability measure for two possible positions are compared. If a relative difference measure of these reliability measure exceeds a predetermined threshold value, the reliability measure indicating the largest reliability corresponds to the correct position of the boundary between the codewords.
    Type: Grant
    Filed: September 11, 1997
    Date of Patent: July 11, 2000
    Assignee: U.S. Philips Corporation
    Inventors: Abraham J. De Bart, Frits A. Steenhof
  • Patent number: 6088829
    Abstract: A synchronous data transfer system includes an oscillation circuit and a plurality of nodes connected to the oscillation circuit and each including at least an internal logic circuit. Each of the nodes outputs a phase reference signal indicating phase of the clock signal, data processed by the internal logic circuit provided internally of the node. The system further includes a transfer end signal indicating an end of the data transfer, in synchronism with the clock signal, and a phase reference signal bus connected to each of the plural nodes, a data bus connected to each of the plural nodes for transmitting the data and a transfer end signal bus connected to each of the plural nodes for transmitting the transfer end signal.
    Type: Grant
    Filed: March 3, 1999
    Date of Patent: July 11, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Masaya Umemura, Toshitsugu Takekuma
  • Patent number: 6069927
    Abstract: A digital signal transmission apparatus, wherein at the time of normal data transmission, an output circuit of a transmitter unit selects transmission data SDAT and converts it to a differential signal for output to the transmission line, while a clock recovery circuit of the receiver unit generates a clock signal LCK matching the frequency of the transmission clock signal TCK and receives the signal based on the same. When the clock signal LCK and the received signal deviate in frequency, the clock reproduction circuit outputs a common mode reference clock request signal to the transmission line. In accordance with this, the transmitter unit selects the reference clock signal RCK for output to the transmission line. The clock recovery circuit of the receiver unit uses this to make the frequency of the clock signal LCK match the transmission clock signal.
    Type: Grant
    Filed: November 12, 1997
    Date of Patent: May 30, 2000
    Assignee: Sony Corporation
    Inventor: Hidekazu Kikuchi
  • Patent number: 6014368
    Abstract: A multiplexing system which detects multiplexing errors, includes PES packetizing modules that packetize elementary streams (ES) to produce packetized elementary streams (PES), and a TS/PS packetizing module that multiplexes packetized elementary streams (PES) to produce transport streams (TS) or program streams (PS). Comparators are provided each to compare a non-packetized elementary stream (ES) or a packetized elementary stream (PES) stored in a FIFO memory with the packetized elementary stream (ES) or packetized elementary stream (PES) from the packetizing modules. Based on the comparison result, a control module detects errors in the packetizing modules.
    Type: Grant
    Filed: March 10, 1997
    Date of Patent: January 11, 2000
    Assignee: OKI Electric Industry Co., Ltd.
    Inventor: Jun Sanami
  • Patent number: 6009551
    Abstract: The partial decoding algorithm for decoding the partially damaged differential satellite positioning system (SATPS) messages is disclosed. The algorithm is based on the modified parity test. The information included in the decoded messages can be used for the high level differential SATPS testing.
    Type: Grant
    Filed: March 3, 1998
    Date of Patent: December 28, 1999
    Assignee: Trimble Navigation Limited
    Inventor: Len Sheynblat
  • Patent number: 6000018
    Abstract: A disk sequencer, which is loaded with control words from a format table and a frame number associated with the first control word loaded, automatically cycles through loaded control words and finds a control word that corresponds to the current position of a data sector. The disk sequencer includes a first counter that is initialized according to a frame number read from a servo sector or according to an index mark and incremented for each end-of-servo pulse so that the first counter accurately indicates the current position of a data head to a data frame granularity. A second counter is loaded with a data frame number associated with the control words, and the second counter is incremented each time the last control word for a data frame is discarded. For automatic alignment, the disk sequencer cycles through and discards control words until comparison of the counts in the two counters indicates the control words are properly aligned.
    Type: Grant
    Filed: June 17, 1997
    Date of Patent: December 7, 1999
    Assignee: Adaptec, Inc.
    Inventors: John S. Packer, Eric C. Erickson
  • Patent number: 5954825
    Abstract: A shift register is used to latch the bus-driver-enable signal for each potential bus driver during each system clock cycle. The shift register clock will freeze upon receipt of a "check stop" signal. Once frozen, the shift register can be scanned for fault isolation analysis.
    Type: Grant
    Filed: April 11, 1997
    Date of Patent: September 21, 1999
    Assignee: International Business Machines Corporation
    Inventors: John Michael Kaiser, Warren Edward Maule
  • Patent number: 5928375
    Abstract: A data transfer system providing parity uses a method and apparatus for transmitting a data clocking signal in a parity bit location along a data bus to latch an accompanying data byte at a receiving device. A transmitting device, coupled to the receiving device through the data bus, generates a data clock signal and latches the clock signal into the parity bit location of the data bus. The clock signal and data byte are then transmitted along the data bus to the receiving device. The receiving device uses the clock signal to latch the data byte from the data bus. Thus, the data transfer system uses the data clock signal transmitted in the parity bit location of the data bus to validate and synchronize the accompanying data byte at the receiving device.
    Type: Grant
    Filed: January 8, 1997
    Date of Patent: July 27, 1999
    Assignee: International Business Machines Corporation
    Inventors: Gregg Steven Lucas, Juan Antonio Yanes