Patents by Inventor William Lo
William Lo has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7403018Abstract: A cable tester that tests cable and that determines a cable status includes a pretest module that senses activity on pairs of the cable and that selectively enables testing based on the sensed activity. A test module is enabled by the pretest module, transmits a test pulse on one of the pairs, measures a reflection amplitude and calculates a cable length. The cable status includes an open status, a short status, and a normal status. The test module determines the cable status based on the measured amplitude and the calculated cable length. The test module measures received signals on at least one other pair after transmitting the test pulse on the one of the pairs, compares the received signals on the at least one other pair to a predetermined threshold, and determines a pair short status between the one of the pairs and the at least one other pair if the received signals exceed the predetermined threshold.Type: GrantFiled: August 24, 2007Date of Patent: July 22, 2008Assignee: Marvell International Ltd.Inventors: William Lo, Yiqing Guo, Tak Tsui, Tsin-Ho Leung, Runsheng He, Eric Janofsky
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Patent number: 7392412Abstract: A network interface comprises a medium access control (MAC) device and/or a host interface. A regulator module communicates with the MAC device and/or the host interface and provides a first voltage level during an inactive mode and a second voltage level during an active mode. A physical layer (PHY) device that communicates with the MAC device and/or the host interface and the regulator module and that includes an energy detect module that detects energy on a medium during the inactive mode and an energy save module. The energy save module starts timing a first period and the regulator module transitions the MAC device and/or the host interface to the second voltage level when the energy is detected during the inactive mode. External communication with the MAC device and/or the host interface is enabled after the first period is up.Type: GrantFiled: April 26, 2005Date of Patent: June 24, 2008Assignee: Marvell International Ltd.Inventor: William Lo
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Patent number: 7375532Abstract: A physical layer device comprises a first port adapted to communicate with one end of a cable. A second port is adapted to communicate with an opposite end of a cable. A cable tester communicates with the first and second ports and selectively tests the cable to determine a cable status, which includes an open status, a short status, and a normal status. The cable tester includes a test module that transmits a test pulse on the cable, measures a reflection amplitude, calculates a cable length, and determines the cable status based on the measured amplitude and the calculated cable length. A frequency synthesizer selectively outputs a plurality of signals at a plurality of frequencies on the first port. An insertion loss calculator that receives the signals on the second port and that estimates insertion loss.Type: GrantFiled: July 11, 2006Date of Patent: May 20, 2008Assignee: Marvell International Ltd.Inventors: William Lo, Yiqing Guo, Tak Tsui, Tsin-Ho Leung, Runsheng He, Eric Janofsky
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Patent number: 7362771Abstract: A First-In-First-Out (FIFO) block to buffer a packet having a size is presented. The FIFO block includes a receiver to receive a data frame including the packet and overhead information, and to extract the packet from the data frame. A buffer has a plurality of memory locations to store the packet in a FIFO configuration. A buffer manager, in response to detecting a buffer low packet condition, stalls reads of the packet from the buffer.Type: GrantFiled: May 30, 2002Date of Patent: April 22, 2008Assignee: Marvell International Ltd.Inventors: William Lo, Samuel Er-Shen Tang, Sabu Ghazali
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Patent number: 7358745Abstract: A physical layer device comprises a first transceiver that selectively communicates with a cable medium. A detector detects a power over Ethernet (POE) device. A switching device selectively provides power from a power supply over the cable medium when the detector detects the POE device. A cable tester communicates with the first transceiver, tests the cable medium and determines a cable status, and delays testing of the cable medium when the detector detects the POE device until the switching device provides the power.Type: GrantFiled: June 19, 2006Date of Patent: April 15, 2008Assignee: Marvell International Ltd.Inventors: William Lo, Yiging Guo, Tek Tsui, Tsin-Ho Leung, Runsheng He, Eric Janofsky
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Patent number: 7343425Abstract: A network device includes a media access control (MAC) device that transmits a first data stream at a first data rate that includes symbols having M bits. A translator converts the first data stream to a second data stream at a second data rate. The translator includes a data appender that appends N bits to the symbols in the first data stream to generate second symbols having M+N bits. A data duplicator duplicates the second symbols X times to produce the second data stream at the second data rate.Type: GrantFiled: August 21, 2003Date of Patent: March 11, 2008Assignee: Marvell International Ltd.Inventors: William Lo, Nafea Bishara
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Patent number: 7340644Abstract: A self-reparable semiconductor includes multiple functional units that perform the same function and that include sub-functional units. The semiconductor includes one or more full or partial spare functional units that are integrated into the semiconductor. If a defect in a sub-functional unit is detected, then that sub-functional unit is switched out and replaced with a sub-functional unit in the full or partial spare functional unit. The reconfiguration is realized with switching devices that are associated with the sub-functional units. Defective functional or sub-functional units can be detected after assembly, during power up, periodically during operation, and/or manually.Type: GrantFiled: July 16, 2004Date of Patent: March 4, 2008Assignee: Marvell World Trade Ltd.Inventors: Sehat Sutardja, Pantas Sutardja, William Lo
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Patent number: 7324507Abstract: A network device includes a media access controller (MAC) and a physical layer device including an interface that communicates with the MAC, and first and second transceivers. A first autonegotiation circuit attempts to establish a first link using the first transceiver over a first medium. A second autonegotiation circuit attempts to establish a second link using the second transceiver over a second medium. A media selector communicates with the interface and the first and second autonegotiation circuits and enables data flow from the first medium to the MAC using the interface when the link over the first medium is established first. When a preferred medium selector prefers the second medium, the media selector monitors the second medium for a qualified energy detect event. When the qualified energy detect event occurs, the media selector allows a link to be established by the second medium.Type: GrantFiled: May 9, 2003Date of Patent: January 29, 2008Assignee: Marvell International Ltd.Inventors: William Lo, Yatin Acharya
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Patent number: 7292596Abstract: A physical layer of an Ethernet network device includes first, second, third and fourth terminals. An autonegotiation circuit includes an autonegotiation wait timer having an autonegotiation wait period. An auto-crossover circuit selectively configures the first and second terminals as one of a transmitter and a receiver and the third and fourth terminals as the other of the transmitter and receiver. The auto-crossover circuit includes a sample timer having a sample timer period that has a value that is greater than or equal to the autonegotiation wait period. The auto-crossover circuit includes a random number generator that communicates with the sample timer and generates n random numbers. The sample timer selects one of n sample timer periods based on the generated random number. The n sample timer periods have values that are greater than or equal to the autonegotiation wait period.Type: GrantFiled: March 26, 2002Date of Patent: November 6, 2007Assignee: Marvell International LtdInventors: Francis Campana, William Lo
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Publication number: 20070248118Abstract: Apparatus having corresponding methods and computer programs comprise a first first-in first-out buffer (FIFO) to receive and store data from a media access controller (MAC); a physical-layer device (PHY) to transmit a signal representing the data; and a control circuit comprising a read circuit to transfer the data from the first FIFO to the PHY, and a transmit pause circuit to transmit a pause frame to the MAC when an amount of the data stored in the first FIFO exceeds a predetermined threshold.Type: ApplicationFiled: April 4, 2007Publication date: October 25, 2007Inventors: Nafea Bishara, William Lo
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Patent number: 7277031Abstract: A physical layer device includes a deserializer that deserializes one of first and second data streams. The first data stream includes successive N-bit sequences having one of all ones and all zeros. A converter oversamples the first data stream, identifies edge transitions in the first data stream to locate N adjacent bits that substantially align with the N-bit sequences, and samples at least one bit of the N adjacent bits.Type: GrantFiled: May 11, 2004Date of Patent: October 2, 2007Assignee: Marvell International Ltd.Inventors: William Lo, Calvin Fang
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Patent number: 7276913Abstract: A cable tester tests cable to determine a cable status. A mode selector selects one of a first operating mode and a second operating mode. A pretest module senses activity on the cable and selectively enables testing based on the sensed activity when in the first operating mode and enables testing when in the second operating mode. A test module is enabled by the pretest module, transmits a test pulse on the cable, measures a reflection amplitude and calculates a cable length. The cable status includes an open status, a normal status and a short status. The test module determines the cable status based on the measured amplitude and the calculated cable length.Type: GrantFiled: November 4, 2004Date of Patent: October 2, 2007Assignee: Marvell International Ltd.Inventors: William Lo, Yiqing Guo, Tak Tsui, Tsin-Ho Leung, Runsheng He, Eric Janofsky
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Patent number: 7278039Abstract: A first physical layer device of a first network device includes a sense circuit that senses activity on a medium and with the first physical layer device. An autonegotiation circuit attempts to establish a connection with a second physical layer device of a second network device within a first period after the sense circuit senses activity. An energy saving circuit selectively provides power to the first physical layer device based on the sensed activity and connection with the second physical layer device, and that while attempting to establish the connection resets a timer associated with the first period when the sense circuit senses activity.Type: GrantFiled: October 20, 2005Date of Patent: October 2, 2007Assignee: Marvell International Ltd.Inventor: William Lo
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Patent number: 7251699Abstract: A physical coding sublayer (PCS) device in a physical layer device of an Ethernet network device includes a multiplexer that aggregates data, which includes at least one of data portions and control portions, from a plurality of data streams into a multiplexed data block. An encoder encodes the multiplexed data block to produce an encoded data block that includes n data blocks. Each of the n data blocks includes at least one of data portions, pointer portions, and control code portions. The control code portions can be located within any of the n data blocks.Type: GrantFiled: June 20, 2003Date of Patent: July 31, 2007Assignee: Marvell International Ltd.Inventor: William Lo
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Patent number: 7250771Abstract: A cable tester comprises a test initiating module that performs B cable tests. Each of said B cable tests includes selectively transmitting a test pulse on the cable, measuring a reflection amplitude, and calculating a cable length. A test results module determines a cable status for each of said B cable tests based on said measured amplitude and said calculated cable length and that determines an overall cable status of the cable based on the cable at least one of passing and failing A out of B cable tests. A and B are integers greater than zero and B is greater than A.Type: GrantFiled: June 19, 2006Date of Patent: July 31, 2007Assignee: Marvell International Ltd.Inventors: William Lo, Yiging Guo, Tek Tsui, Tsin-Ho Leung, Runsheng He, Eric Janofsky
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Patent number: 7246018Abstract: An interpolator testing system and method comprises an interpolator that includes a phase shift module. The phase shift module receives a reference clock signal and generates M clock signals having phase shifts in increments of 360/M degrees relative to the reference clock signal. A phase select module receives the reference clock signal and a recovered clock signal during a normal mode and generates a select signal based on a comparison of the reference clock signal and the recovered clock signal during the normal mode. A selector receives the M clock signals and outputs one of the M clock signals as the recovered clock signal based on the select signal. A recovered clock counter counts an attribute of the recovered clock signal during a test mode. The phase select module sequentially selects the M clock signals N times during the test mode.Type: GrantFiled: May 24, 2004Date of Patent: July 17, 2007Assignee: Marvell International Ltd.Inventors: William Lo, Francis Campana
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Patent number: 7242693Abstract: A first network device includes a first physical layer device with a first autonegotiation circuit. A bypass timer determines a predetermined period. A second network device includes a second physical layer device. The first network device enables autonegotiation bypass and establishes a link with the second network device after the predetermined period during which a link between the first and second network devices is not up, a receiver of the first physical layer device is in sync, and an ability detect state of the first autonegotiation circuit is true. The first autonegotiation circuit resets the predetermined period of the bypass timer when configuration code groups are received from the second network device. When the first network device receives idle code groups followed by data code groups, the first autonegotiation circuit does not return to an autonegotiation enable state.Type: GrantFiled: February 11, 2003Date of Patent: July 10, 2007Assignee: Marvell International Ltd.Inventors: Yatin Acharya, William Lo, Sundeep Gupta
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Patent number: 7221294Abstract: A physical layer device for a network device comprises a converter module that selectively converts an n-bit input to an m-bit output based on first and second mapping functions. A scrambler module selectively scrambles the m-bit output. An encoding module receives the m-bit output from the scrambler module and selectively maps the m-bit output based on the first mapping function to X level output signals and the m-bit output based on the second mapping function to Y level output signals, where X and Y are integers greater than one and X is different than Y.Type: GrantFiled: November 3, 2006Date of Patent: May 22, 2007Assignee: Marvell International Ltd.Inventors: William Lo, Xiaopeng Chen
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Patent number: 7203851Abstract: A first network device supplies power to a second network device in communication therewith. The first network device comprises a physical layer device which includes a pulse generator to generate a test signal comprising n sub-pulses to be transmitted to the second network device, wherein in n being greater than 2. A detector is responsive to the second network device, and a controller is in communication with the detector and the pulse generator. When the detector detects j pulses which are greater than a predetermined threshold, 1?j<n, the controller, responsive to the detector, enables power to be transmitted to the second network device.Type: GrantFiled: March 15, 2002Date of Patent: April 10, 2007Assignee: Marvell International Ltd.Inventors: William Lo, Yi Cheng, Leechung Yiu, Calvin Fang
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Patent number: 7190172Abstract: A physical layer device includes first, second, third and fourth twisted pairs. First, second, third and fourth hybrid devices communicate with the first, second, third and fourth twisted pairs, respectively. First, second, third and fourth cable testers communicate with the first, second, third and fourth hybrid devices, respectively. Each of the cable testers tests the first, second, third and fourth twisted pairs and determines a cable status of the first, second, third and fourth twisted pairs during first, second, third and fourth periods, respectively. At least one of the first, second, third and fourth periods overlaps another of the first, second, third and fourth periods.A cable testing system and method tests cable and determines status, cable length and reflection amplitude. The test module includes a pretest state machine that senses activity on the cable and enables testing if activity is not detected for a first period.Type: GrantFiled: October 1, 2004Date of Patent: March 13, 2007Assignee: Marvell International Ltd.Inventors: William Lo, Yiqing Guo