Patents by Inventor Sam Chu
Sam Chu 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: 7920592Abstract: A method of bandwidth control and a corresponding bandwidth control device are disclosed, in which a plurality of queues are provided, bandwidth is assigned to each of the queues on the basis of a strict priority scheme, and additional bandwidth is assigned to the queues on the basis of a fair queuing scheme.Type: GrantFiled: December 20, 2006Date of Patent: April 5, 2011Assignee: Lantiq Deutschland GmbHInventors: Chia Sheng Lu, Sam Chu
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Publication number: 20080151920Abstract: A method of bandwidth control and a corresponding bandwidth control device are disclosed, in which a plurality of queues are provided, bandwidth is assigned to each of the queues on the basis of a strict priority scheme, and additional bandwidth is assigned to the queues on the basis of a fair queuing scheme.Type: ApplicationFiled: December 20, 2006Publication date: June 26, 2008Applicant: Infineon Technologies AGInventors: Chia Sheng Lu, Sam Chu
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Publication number: 20070240023Abstract: A circuit permits a user to present signals to control the flow of data from a first-type cell to a second-type cell. The circuit is susceptible to loading each cell individually, as well as loading cells by means of scanning input in a series through a low order cell to a higher order cell. The circuit may be copied as a series of cells wherein a bit held in each first-type cell is copied to the next higher second-type cell.Type: ApplicationFiled: April 3, 2006Publication date: October 11, 2007Inventors: Vikas Agarwal, Sam Chu, Hung Le
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Publication number: 20070229132Abstract: A latch is described that provides soft error rate protection with integrated scan capability and collision avoidance. The latch has a latch output node and a first, second, and third sublatches. Each sublatch has a respective input circuitry, output node, and feedback circuitry coupled to the output node for reinforcing an output signal of the sublatch. Each sublatch is operable to receive a data signal at its input circuitry and responsively generate a binary-state output signal on its output nodes. The first and second output nodes such that, if an output of the third sublatch changes, the first and second sublatches force the third sublatch to have a same output. This “forced” change reduces the soft error rate in the latch and the output signal of the latch output node is restored without the sublatches colliding.Type: ApplicationFiled: March 28, 2006Publication date: October 4, 2007Inventors: Sam Chu, Peter Klim, Michael Lee, Jose Paredes
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Publication number: 20070171757Abstract: A system and method of selective row energization based on write data, with a selective row energization system including a storage array 102 having M rows 104 and N columns 106; an N-bit data word register 108; a uniform-detect circuit 110 responsive to a data word to generate a uniform word data bit having a first value when the data word is uniform; an M-bit uniform-detect register 112 having M uniform-detect latches 114, each being associated with one of the M rows 104 and storing the uniform word data bit for the data word stored in the associated M row 104; and an M-bit row driver device 116 responsive to the uniform word data bit for each of the M rows 104 to inhibit energization of the M rows 104 for which the uniform word data bit is the first value.Type: ApplicationFiled: January 26, 2006Publication date: July 26, 2007Inventors: Michael Lee, Jose Paredes, Peter Klim, Sam Chu
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Publication number: 20060184852Abstract: A method, system and apparatus for detecting soft errors in non-dataflow circuits. In a preferred embodiment, input is received at a latch system. The latch system consists of two pairs of latches. The second pair of latches is parallel to the first pair of latches. Both pairs of latches capture the input. However, the second pair of latches captures the input later in time relative to the first pair of latches latch. The captured input is then transferred from the first latch in each pair of latches to the second latch in each pair of latches. A comparison is made of the input in the two second latches. If the input captured in the two second latches is not the same, then a message is sent to a recovery unit.Type: ApplicationFiled: February 3, 2005Publication date: August 17, 2006Applicant: International Business Machines CorporationInventors: Sam Chu, Peter Klim, Michael Lee, Jose Paredes
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Publication number: 20060179257Abstract: An apparatus and method are provided for reading a plurality of consecutive entries and writing a plurality of consecutive entries with only one read address and one write address using a 2Read/2Write register file. In one exemplary embodiment, a 64 entry register file array is partitioned into four sub-arrays. Each sub-array contains sixteen entries having one or more 2Read/2Write SRAM cells. The apparatus and method provide a mechanism to write the consecutive entries by only having a 4 to 16 decode of one address. In addition, the apparatus and method provide a mechanism for reading data from the register file array using a starting read word address and two read word lines generated based on the starting read word address. The two read word lines are used to access the two read ports of the entries in the sub-arrays.Type: ApplicationFiled: February 9, 2005Publication date: August 10, 2006Inventors: Sam Chu, Maureen Delaney, Saiful Islam, Dung Nguyen, Jafar Nahidi
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Publication number: 20060171208Abstract: An apparatus and method for speeding up access time of a large register file with wrap capability are provided. With the apparatus and method, the 2:1 multiplexers in conventional register file systems are eliminated from the circuit configuration and instead, additional primary multiplexers are provided for half of the addresses, e.g., the first four sub-arrays of the register file for which the wrap capability is needed. These additional primary multiplexers receive the read address and a shifted read word line signal. The other primary multiplexer receives the read address and an unshifted read word line signal. The outputs from the shifted and non-shifted primary multiplexers are provided to a set of secondary multiplexers which multiplex bits from the outputs of the shifted and non-shifted primary multiplexers to generate the read addresses to be used by the multiple read/write register file system.Type: ApplicationFiled: January 27, 2005Publication date: August 3, 2006Inventors: Sam Chu, Maureen Delaney, Saiful Islam, Jafar Nahidi, Dung Nguyen
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Publication number: 20060038588Abstract: A dynamic-static logical control element for signaling an interval between the end of a control signal and a logical evaluation provides a compact circuit for blocking the indication of a non-evaluated state of a dynamic logic gate until a control signal has ended. The control signal is connected to a precharge input of the control element and a summing node is connected to one or more evaluation trees and to the control element output via an inverter. The inverter is connected to an override circuit that forces the output of the control element to a state opposite the precharge state until the control signal has ended. The output of the control element then assumes a state corresponding to the precharge state until an evaluation occurs. The control element output thus produces a window signal indicating the interval between the end of the control signal and the evaluation.Type: ApplicationFiled: August 19, 2004Publication date: February 23, 2006Applicant: International Business Machines CorporationInventors: Sam Chu, Peter Klim, Michael Hyeok Lee, Jose Paredes
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Publication number: 20060039203Abstract: A register file apparatus and method incorporating read-after-write blocking using detection cells provides improved read access times in high performance register files. One or more detection cells identical to the register file cells and located in the register file array are used to control the read operation in the register file by configuring the detection cells to either alternate value at each write or change to a particular value after a write and then detecting when the write has completed by detecting the state change of an active detection cell. The state change detection can be used to delay the leading edge of a read strobe or may be used in the access control logic to delay generation of a next read strobe. The register file thus provides a scalable design that does not have to be tuned for each application and that tracks over voltage and clock skew variation.Type: ApplicationFiled: August 19, 2004Publication date: February 23, 2006Applicant: International Business Machines CorporationInventors: Sam Chu, Peter Klim, Michael Lee, Jose Paredes
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Publication number: 20050216698Abstract: A register file is often used within integrated circuitry to temporarily hold data. Sometimes this data needs to be retained within the register file for a period of time, such as when there is a stall operation. Conventional register files have utilized a hold multiplexor to perform such a stall operation. The multiplexor however inserts a delay that is undesirable in high performance integrated circuitry. The multiplexor is replaced with a tri-state inverter coupled to the global bit line of the register file, which minimizes this additional delay from the register file data access time.Type: ApplicationFiled: March 11, 2004Publication date: September 29, 2005Applicant: International Business Machines CorporationInventors: Sam Chu, Saiful Islam, Shelton Leung, Jose Paredes
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Publication number: 20050099851Abstract: A bit-read apparatus includes a first decoder and N multiplexers, each having Q output nodes and Q pull-ups coupled thereto. Respective multiplexers have M selectors coupled to N×M respective select lines and register-file cells. The selectors are in Q groups coupled to respective output nodes. Each multiplexer has a logic gate with inputs coupled to respective multiplexer output nodes. A second decoder is coupled to an N+1th multiplexer having R output nodes and R pull-ups coupled thereto. The N+1th multiplexer also has N selectors, coupled to respective select lines of the second decoder and respective output logic gates of the N multiplexers. The N selectors are in R groups coupled to the R nodes. An output logic gate for N+1th multiplexer has R inputs coupled respectively to the R nodes. Each pull-up of the multiplexers drives its respective multiplexer output node responsive to an address-bit signal.Type: ApplicationFiled: November 6, 2003Publication date: May 12, 2005Applicant: International Business Machines CorporationInventors: Sam Chu, Peter Klim, Michael Lee, Jose Paredes
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Publication number: 20050099205Abstract: A register-file bit read apparatus includes a decoder operable to receive a number of address-bit signals and responsively assert a select signal on one of M select lines. Each select line corresponds to a respective one of M register-file cells. The apparatus also includes a multiplexer having Q output nodes and M selectors. Each selector is coupled to one of the select lines and that select line's corresponding register-file cell. The selectors are in Q groups, each coupled to a respective one of the multiplexer's output nodes. The apparatus also includes an output logic gate having Q inputs, coupled to respective ones of the multiplexer output nodes. The multiplexer includes Q pull-ups, each of which is coupled to a respective one of the multiplexer output nodes and is operable to drive its multiplexer output node responsive to one of the address-bit signals.Type: ApplicationFiled: November 6, 2003Publication date: May 12, 2005Applicant: International Business Machines CorporationInventors: Sam Chu, Peter Klim, Michael Lee, Jose Paredes
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Publication number: 20050083774Abstract: A memory array includes a storage unit with a number of sections and decoders coupled to respective ones of the sections for decoding an N-bit address signal and responsively asserting a signal on one of the word lines selected by the address signal. Local clock buffers are coupled to respective ones of the decoders for receiving a clock signal and an address signal including M most-significant bits of the N-bit address signal and generating respective timing signals. The decoders receive the timing signal from their respective local clock buffers. Each decoder is operable to alternately precharge and evaluate the N-bit address signal responsive to phases of the timing signal. Each local clock buffer is operable, responsive to a state of the M bits of the address signal, for selecting between holding its timing signal in a deasserted state and enabling its timing signal to follow the clock signal.Type: ApplicationFiled: October 16, 2003Publication date: April 21, 2005Applicant: International Business Machines CorporationInventors: Tai Cao, Sam Chu, Joseph McGill, Michael Vaden
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Patent number: 5783471Abstract: A structure and method are provided which reduce memory cell size by forming self-formed contacts and self-aligned source lines in the array. In one embodiment of the present invention, a plurality of self-aligned memory cells are formed in an array. Then, a first insulating layer is deposited on the array, and subsequently etched to form spacers on the sidewalls of each memory cell. Conductive plugs are then formed between adjacent spacers. Subsequently, a second insulating layer is deposited over the array. Finally, drain contacts are formed through the second insulating layer a first set of plugs. Other plugs form source lines for the array. Because the present invention provides a self-formed contact, only the second insulating layer is etched to establish contact between a metal bit line and an underlying diffused drain region. Thus, the present invention ensures appropriate isolation for each memory cell while reducing the area required for contact formation.Type: GrantFiled: November 9, 1994Date of Patent: July 21, 1998Assignee: Catalyst Semiconductor, Inc.Inventor: Sam Chu
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Patent number: 5519239Abstract: A structure and method are provided which reduce memory cell size by forming self-formed contacts and self-aligned source lines in the array. In one embodiment of the present invention, a plurality of memory cells are formed in an array. Then, a first insulating layer is deposited on the array, and subsequently etched to form spacers on the sidewalls of each memory cell. Conductive plugs are then formed between adjacent spacers. Subsequently, a second insulating layer is deposited over the array. Finally, drain contacts are formed through the second insulating layer to a first set of plugs. Other plugs form source lines for the array. Because the present invention provides a self-formed contact, only the second insulating layer is etched to establish contact between a metal bit line and an underlying diffused drain region. Thus, the present invention ensures appropriate isolation for each memory cell while reducing the area required for contact formation.Type: GrantFiled: November 10, 1994Date of Patent: May 21, 1996Assignee: Catalyst Semiconductor Corp.Inventor: Sam Chu