Patents by Inventor Cong Khieu
Cong Khieu 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: 8349676Abstract: Apparatus, systems, and methods may include managing electrostatic discharge events by using a semiconductor device having a non-aligned gate to implement a snap-back voltage protection mechanism. Such devices may be formed by doping a semiconductor substrate to form a first conductive region as a well, forming one of a source region and a drain region in the well, depositing a layer of polysilicon on the substrate to establish a gating area that does not overlap the one of the source region and the drain region, and forming an integrated circuit supported by the substrate to couple to the one of the source region and the drain region to provide snap-back voltage operation at a node between the integrated circuit and the source or drain region. Additional apparatus, systems, and methods are disclosed.Type: GrantFiled: August 19, 2011Date of Patent: January 8, 2013Assignee: Synopsys, Inc.Inventors: Cong Khieu, Yanjun Ma, Jaideep Mavoori
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Publication number: 20110298051Abstract: Apparatus, systems, and methods may include managing electrostatic discharge events by using a semiconductor device having a non-aligned gate to implement a snap-back voltage protection mechanism. Such devices may be formed by doping a semiconductor substrate to form a first conductive region as a well, forming one of a source region and a drain region in the well, depositing a layer of polysilicon on the substrate to establish a gating area that does not overlap the one of the source region and the drain region, and forming an integrated circuit supported by the substrate to couple to the one of the source region and the drain region to provide snap-back voltage operation at a node between the integrated circuit and the source or drain region. Additional apparatus, systems, and methods are disclosed.Type: ApplicationFiled: August 19, 2011Publication date: December 8, 2011Applicant: SYNOPSYS, INC.Inventors: Cong Khieu, Yanjun Ma, Jaideep Mavoori
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Patent number: 8035486Abstract: Apparatus, systems, and methods may include providing a power-on reset function to many types of receiving circuitry, including radio frequency identification (RFID) tag processing circuitry. Thus, the power-on reset function may be realized by applying a supply voltage to a power-on reset circuit coupled to RFID tag processing circuitry. Operations may include sensing a first current substantially independent of the supply voltage, sensing a second current substantially dependent on the supply voltage, and indicating a power-on reset condition based on a comparison between the first current and the second current. Additional apparatus, systems, and methods are disclosed.Type: GrantFiled: December 10, 2010Date of Patent: October 11, 2011Assignee: Synopsys, Inc.Inventor: Cong Khieu
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Patent number: 8022498Abstract: Apparatus, systems, and methods may include managing electrostatic discharge events by using a semiconductor device having a non-aligned gate to implement a snap-back voltage protection mechanism. Such devices may be formed by doping a semiconductor substrate to form a first conductive region as a well, forming one of a source region and a drain region in the well, depositing a layer of polysilicon on the substrate to establish a gating area that does not overlap the one of the source region and the drain region, and forming an integrated circuit supported by the substrate to couple to the one of the source region and the drain region to provide snap-back voltage operation at a node between the integrated circuit and the source or drain region. Additional apparatus, systems, and methods are disclosed.Type: GrantFiled: August 13, 2007Date of Patent: September 20, 2011Assignee: Synopsys, Inc.Inventors: Cong Khieu, Yanjun Ma, Jaideep Mavoori
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Patent number: 7872566Abstract: Apparatus, systems, and methods may include providing a power-on reset function to many types of receiving circuitry, including radio frequency identification (RFID) tag processing circuitry. Thus, the power-on reset function may be realized by applying a supply voltage to a power-on reset circuit coupled to RFID tag processing circuitry. Operations may include sensing a first current substantially independent of the supply voltage, sensing a second current substantially dependent on the supply voltage, and indicating a power-on reset condition based on a comparison between the first current and the second current. Additional apparatus, systems, and methods are disclosed.Type: GrantFiled: December 27, 2007Date of Patent: January 18, 2011Assignee: Synopsys, Inc.Inventor: Cong Khieu
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Patent number: 7843316Abstract: Apparatus, systems, and methods may include providing a power-on reset function to many types of receiving circuitry, including processors, memories, and radio frequency identification (RFID) tag processing circuitry. Thus, the power-on reset function may be realized by applying a supply voltage to a power-on reset circuit coupled to the processing circuit of an RFID tag. Additional activity may include sensing a first current substantially independent of the supply voltage, sensing a second current substantially dependent on the supply voltage, and indicating a power-on reset condition based on a comparison between the first current and the second current. Additional apparatus, systems, and methods are disclosed.Type: GrantFiled: August 21, 2007Date of Patent: November 30, 2010Assignee: Synopsys, Inc.Inventor: Cong Khieu
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Patent number: 7843032Abstract: Apparatus, systems, and methods may include managing electrostatic discharge events in radio frequency identification (RFID) devices by using a semiconductor circuit having a non-aligned gate to implement a snap-back voltage protection mechanism. Such circuits may be formed by doping a semiconductor substrate to form a first conductive region as a well, forming one of a source region and a drain region in the well, depositing a layer of polysilicon on the substrate to establish a gating area that does not overlap the one of the source region and the drain region, and forming an integrated circuit including an RFID circuit that is supported by the substrate to couple to the one of the source region and the drain region to provide snap-back voltage operation at a node between the integrated circuit and the source or drain region. Additional apparatus, systems, and methods are disclosed.Type: GrantFiled: December 27, 2007Date of Patent: November 30, 2010Assignee: Synopsis, Inc.Inventors: Cong Khieu, Yanjun Ma, Jaideep Mavoori
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Patent number: 7111186Abstract: A CPU clock signal generated from a phase lock loop (PLL) circuit and a feedback signal of the PLL circuit are used in generating a JBUS clock signal. The CPU clock signal and the feedback signal include the same amount of static phase offset introduced by the PLL circuit. The CPU clock signal and the feedback signal are input to an alignment detection circuit and used in generating the JBUS clock signal. In one embodiment, the JBUS clock signal is generated in synchronization with the CPU clock signal and having the frequency of the feedback signal. The present invention reduces or eliminates misalignment of the leading edge of the JBUS signal with reference to a specific leading edge of the CPU clock signal due to the presence of static phase offset introduced by the PLL circuit.Type: GrantFiled: April 28, 2003Date of Patent: September 19, 2006Assignee: Sun Microsystems, Inc.Inventors: Zhigang Han, Cong Khieu, Kailashnath Nagarakanti
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Publication number: 20040215993Abstract: A CPU clock signal generated from a phase lock loop (PLL) circuit and a feedback signal of the PLL circuit are used in generating a JBUS clock signal. The CPU clock signal and the feedback signal include the same amount of static phase offset introduced by the PLL circuit. The CPU clock signal and the feedback signal are input to an alignment detection circuit and used in generating the JBUS clock signal. In one embodiment, the JBUS clock signal is generated in synchronization with the CPU clock signal and having the frequency of the feedback signal. The present invention reduces or eliminates misalignment of the leading edge of the JBUS signal with reference to a specific leading edge of the CPU clock signal due to the presence of static phase offset introduced by the PLL circuit.Type: ApplicationFiled: April 28, 2003Publication date: October 28, 2004Applicant: Sun Microsystems, Inc.Inventors: Zhigang Han, Cong Khieu, Kailashnath Nagarakanti
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Patent number: 6493790Abstract: A translation-lookaside buffer includes a content-addressable memory (CAM) cell to generate a CAM current signal with a first transistor configuration having a set of transistors of a predetermined size and connection. A reference current circuit generates a reference current signal with a second transistor configuration corresponding to the first transistor configuration, with the exception of the size and connection of selected transistors. A match sense amplifier selectively generates a match signal in response to the CAM current signal and the reference current signal.Type: GrantFiled: January 30, 1998Date of Patent: December 10, 2002Assignee: Sun Microsystems, Inc.Inventors: Cong Khieu, Xin Liu, Der-ren Chu, Lan Lee
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Patent number: 6421290Abstract: A memory has memory cells arranged in rows and columns. The memory cells of each row are coupled to a word line that is separate from word lines connecting to the memory cells of other rows. Each column has mutually exclusive subsets of memory cells. The memory cells are coupled to bit lines. Each bit line is coupled to a selected mutually exclusive subset of memory cells. The memory cells of a selected row output a cell voltage on the coupled bit lines when the coupled word line is asserted. A multiplexor receives the cell voltages on the bit lines. The multiplexor is responsive to column select signals to select one of the columns as a selected column, and outputs a multiplexor voltage corresponding to the cell voltage of the memory cell of the selected row and the selected column.Type: GrantFiled: April 23, 2001Date of Patent: July 16, 2002Assignee: Sun Microsystems, Inc.Inventor: Cong Khieu
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Publication number: 20010050866Abstract: A memory has memory cells arranged in rows and columns. The memory cells of each row are coupled to a word line that is separate from word lines connecting to the memory cells of other rows. Each column has mutually exclusive subsets of memory cells. The memory cells are coupled to bit lines. Each bit line is coupled to a selected mutually exclusive subset of memory cells. The memory cells of a selected row output a cell voltage on the coupled bit lines when the coupled word line is asserted. A multiplexor receives the cell voltages on the bit lines. The multiplexor is responsive to column select signals to select one of the columns as a selected column, and outputs a multiplexor voltage corresponding to the cell voltage of the memory cell of the selected row and the selected column.Type: ApplicationFiled: April 23, 2001Publication date: December 13, 2001Applicant: Sun Microsystems, Inc.Inventor: Cong Khieu
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Patent number: 6222777Abstract: A memory has memory cells arranged in rows and columns. The memory cells of each row are coupled to a word line that is separate from word lines connecting to the memory cells of other rows. Each column has mutually exclusive subsets of memory cells. The memory cells are coupled to bit lines. Each bit line is coupled to a selected mutually exclusive subset of memory cells. The memory cells of a selected row output a cell voltage on the coupled bit lines when the coupled word line is asserted. A multiplexor receives the cell voltages on the bit lines. The multiplexor is responsive to column select signals to select one of the columns as a selected column, and outputs a multiplexor voltage corresponding to the cell voltage of the memory cell of the selected row and the selected column.Type: GrantFiled: April 9, 1999Date of Patent: April 24, 2001Assignee: Sun Microsystems, Inc.Inventor: Cong Khieu
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Patent number: 6163192Abstract: A negative edge triggered flip-flop generates an output pulse in response to a negative edge of a clock signal. A first set of nodes receives data input signals, and a second set of nodes receives select input signals for selecting one data input signal as a selected data input signal. The clock node receives the clock signal which has a positive edge and a negative edge. A header circuit connects to the second set of nodes and to the clock node, and integrates the clock signal with the select input signals to generate at least one control signal. A pulse generator circuit connects to the first set of nodes, the header circuit and the output node. The pulse generator circuit generates an output pulse on the output node in response to a control signal and the selected data input signal.Type: GrantFiled: February 26, 1999Date of Patent: December 19, 2000Assignee: Sun Microsystems, Inc.Inventors: Lan Lee, Hiep P. Ngo, Cong Khieu
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Patent number: 6121871Abstract: A circuit for comparing two digital words has a set of bit compare circuits that generate a set of compare signals. Each bit compare circuit receives a first bit from a first digital word and a corresponding bit from a second digital word and generates one compare signal that indicates a match between the first bit and the corresponding bit. In response to the set of compare signals, a composite match detector circuit generates a composite match signal. A last bit detector circuit generates a last bit signal that indicates a match between a last bit from the first digital word and a last bit from the second digital word. When the last bit signal is received, a match hit generator circuit generates a match hit signal based on the composite match signal and the last bit signal.Type: GrantFiled: March 1, 1999Date of Patent: September 19, 2000Assignee: Sun Microsystems, Inc.Inventors: Lan Lee, Cong Khieu
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Patent number: 5304918Abstract: A reference circuit for supplying current to high speed logic elements in an integrated circuit supplies less current when circuit temperature decreases while a supply voltage remains constant. The reference circuit supplies less current when the supply voltage increases while circuit temperature remains constant. A resistance with a temperature coefficient, in some embodiments a negative temperature coefficient, is used to decrease current flow in a first leg of an output mirror when temperature decreases. A feedback circuit is used to decrease current flow in the first leg of the output current mirror when the feedback circuit senses an increase in supply voltage by sensing a voltage change on a common control node of the output current mirror. The reference circuit sees many applications including supplying current to logic gates, input/output buffers, and sense amplifiers.Type: GrantFiled: January 22, 1992Date of Patent: April 19, 1994Assignee: Samsung Semiconductor, Inc.Inventor: Cong Khieu
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Patent number: 5243237Abstract: In a noninverting Bi-CMOS gate, one or more passgates are utilized in the control path leading to a bipolar output transistor which switches the output of the Bi-CMOS gate. The control gate of one of the MOS transistors of a passgate is connected to an input signal of the Bi-CMOS gate. The control gate of the other MOS transistor is connected to the complement of the input signal. The output of the passgate is connected to the base of the bipolar output transistor. More than one such passgate connected to an input signal and its complement can be used. If multiple passgates are used, the outputs of the passgates may be tied together. This technique, utilizing the switching of the passgates with the input signals and their complements, is employed to create a family of Bi-CMOS noninverting gates such as buffers and AND gates. The propagation delay through the noninverting Bi-CMOS gates of the present invention are roughly equal to the propagation delay of a single Bi-CMOS inverter.Type: GrantFiled: January 22, 1992Date of Patent: September 7, 1993Assignee: Samsung Semiconductor, Inc.Inventor: Cong Khieu