Patents Assigned to SEEQ Technology, Incorporated
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Patent number: 5920897Abstract: An apparatus and method for aligning any number of multiple parallel channels of data signals according to a single clock is provided. The synchronization process is accomplished through the use of a First-In-First-Out (FIFO) principle and individual storage elements implementing the FIFO principle for each received data channel. Each channel's data signals are read into a corresponding storage element, maintained in order, and read out upon the assertion of read signals in synchronization with a designated single clock signal. The apparatus and method preferably uses indications of data ready to be read from a storage element implementing the FIFO principle and the presence of a master clock signal to activate the reading of the data from the corresponding storage element. Therefore, each data channel is fully aligned with the master clock signal. The clock-data alignment function may be implemented for a 100BASE-T4 receiver.Type: GrantFiled: August 7, 1996Date of Patent: July 6, 1999Assignee: Seeq Technology, IncorporatedInventors: Robert X. Jin, Eric T. West, Stephen F. Dreyer
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Patent number: 5768301Abstract: The present invention allows for the detection and correction of certain error conditions in packet-based data communications systems, including systems utilizing multiple channels or signal pairs, where all channels or signal pairs do not carry a link integrity signal or other repetitive non-data signal. A first aspect of the present invention provides detection and correction for reverse polarity. A second aspect of the present invention provides detection and correction for pair swap. A third aspect of the present invention provides a link integrity function. Detection of reverse polarity, detection of pair swap, and detection of link integrity utilizes the non-data components of received packets, either independently or in conjunction with a link integrity signal or other repetitive non-data signal. Reverse polarity is corrected by inverting the received signals prior to transmission or repetition to subsequent circuitry.Type: GrantFiled: May 20, 1997Date of Patent: June 16, 1998Assignee: SEEQ Technology, IncorporatedInventors: Stephen F. Dreyer, Robert X. Jin, Eric T. West
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Patent number: 5648956Abstract: A downward compatible full-duplex ethernet transceiver associated with either the hub or the remote node in an ethernet local area network (LAN) includes generator circuitry for generating a full-duplex-capability signal indicating its full-duplex capability for transmission over a link of the LAN and detector circuitry for detecting transmission of such a signal from the transceiver with which it is communicating across the link of the LAN. The detector circuitry responds to the full-duplex-capability signal by sending a full-duplex enable signal to an ethernet controller configured according to the present invention. An ethernet controller contains circuitry responsive to the full-duplex-enable signal to disable transmission deferral in response to a carrier-sense signal generated by the transceiver. The full-duplex-capability indicator portion may comprise an extra pulse following an Nth link-integrity pulse after a delay of from about 2 to about 7 microseconds.Type: GrantFiled: December 27, 1995Date of Patent: July 15, 1997Assignee: Seeq Technology, IncorporatedInventors: Namakkal S. Sambamurthy, Woo-Ping Lai, John P. VanGilder
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Patent number: 5311114Abstract: A downward compatible full-duplex 10Base-T ethernet transceiver associated with either the hub or the remote node in an ethernet network includes generator circuitry for generating a full-duplex-capability signal indicating its full-duplex capability for transmission over the twisted pair link and detector circuitry for detecting transmission of such a signal from the transceiver with which it is communicating across the twisted pair link. The detector circuitry responds to the full-duplex-capability signal by sending a full-duplex enable signal to an ethernet controller configured according to the present invention. An ethernet controller contains circuitry responsive to the full-duplex-enable signal to disable transmission deferral in response to a carrier-sense signal generated by the transceiver. The full-duplex-capability indicator portion may comprise an extra pulse following an Nth link-integrity pulse after a delay of between about 2-7 .mu.sec.Type: GrantFiled: October 27, 1992Date of Patent: May 10, 1994Assignee: Seeq Technology, IncorporatedInventors: Namakkal S. Sambamurthy, Woo-Ping Lai, John P. VanGilder
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Patent number: 5101379Abstract: An apparatus for page mode programming of an EEPROM cell array with false loading protection is disclosed. The system includes a flip-flop operatively connected to a bit line for storing information to be loaded into an EEPROM memory cell, and false loading protection circuitry operatively connected to the bit line for preventing the false loading of an erroneous signal into the flip-flop and/or an EEPROM cell.Type: GrantFiled: July 10, 1990Date of Patent: March 31, 1992Assignee: SEEQ Technology, IncorporatedInventors: Tien-Ler Lin, Dumitru Cioaca
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Patent number: 5029131Abstract: A fault tolerant memory and method for sensing is disclosed. A pair of memory cells each including a memory device and a select device are connected to a pair of bit lines. The bit lines are connected through select devices to a differential sense amplifier. Each pair of memory cells stores a single bit of data; the first memory cell stores the data bit and the second memory cell stores the compliment of the data bit. The memory cells are fabricated such that they exhibit three states; a first state in which they conduct current, a second state in which they do not conduct current, and a third, abnormal, state into which they fail wherein they conduct approximately half of the current which would be conducted in the first state.Type: GrantFiled: June 29, 1988Date of Patent: July 2, 1991Assignee: SEEQ Technology, IncorporatedInventor: Radu M. Vancu