Patents Represented by Attorney, Agent or Law Firm Robert Walsh
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Patent number: 8279687Abstract: A reduced bitline precharge level has been found to increase the SRAM Beta ratio, thus improving the stability margin. The precharge level is also supplied to Sense amplifier, write driver, and source voltages for control signals. In the sense amplifier, the lower precharge voltage compensates for performance loss in the bit-cell by operating global data-line drivers with increased overdrive. In the write driver, the reduced voltage improves the Bitline discharge rate, improves the efficiency of the negative boost write assist, and decreases the reliability exposure of transistors in the write path from negative boost circuit.Type: GrantFiled: May 13, 2010Date of Patent: October 2, 2012Assignee: International Business Machines CorporationInventors: Chad A. Adams, George M. Braceras, Daniel M Nelson, Harold Pilo, Vinod Ramadurai
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Patent number: 7704804Abstract: A crack stop void is formed in a low-k dielectric or silicon oxide layer between adjacent fuse structures for preventing propagation of cracks between the adjacent fuse structures during a fuse blow operation. The passivation layer is fixed in place by using an etch stop shape of conducting material which is formed simultaneously with the formation of the interconnect structure. This produces a reliable and repeatable fuse structure that has controllable passivation layer over the fuse structure that is easily manufactured.Type: GrantFiled: December 10, 2007Date of Patent: April 27, 2010Assignee: International Business Machines CorporationInventors: Timothy Daubenspeck, Jeffrey Gambino, Christopher Muzzy, Wolfgang Sauter
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Patent number: 7688611Abstract: This patent describes a method for switching search-lines in a Content Addressable Memory (CAM) asynchronously to improve CAM speed and reduce CAM noise without affecting its power performance. This is accomplished by resetting the match-lines prior to initiating a search and then applying a search word to the search-lines. A reference match-line is provided to generate the timing for the search operation and provide the timing for the asynchronous application of the search data on the SLs. Additional noise reduction is achieved through the staggering of the search data application on the SLs through programmable delay elements.Type: GrantFiled: March 12, 2008Date of Patent: March 30, 2010Assignee: International Business Machines CorporationInventors: Igor Arsovski, Rahul K. Nadkami, Reid A. Wistort
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Patent number: 7515449Abstract: This patent describes a method for switching search-lines in a Content Addressable Memory (CAM) asynchronously to improve CAM speed and reduce CAM noise without affecting its power performance. This is accomplished by resetting the match-lines prior to initiating a search and then applying a search word to the search-lines. A reference match-line is provided to generate the timing for the search operation and provide the timing for the asynchronous application of the search data on the SLs. Additional noise reduction is achieved through the staggering of the search data application on the SLs through programmable delay elements.Type: GrantFiled: September 15, 2006Date of Patent: April 7, 2009Assignee: International Business Machines CorporationInventors: Igor Arsovski, Rahul K. Nadkarni, Reid A. Wistort
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Patent number: 7401278Abstract: A binary latch that operates as an edge-triggered flip-flop and which is LSSD-testable that comprises an edge triggered master. The binary latch comprises an edge triggered master flip-flop (2), with a clock input connected to the system clock (SYS_CLK), with a data input (DI) and with an output (DO), a level sensitive scan design (LSSD) slave latch (3), connected to the output (DO) of the master flip-flop (2), a NAND gate (4) with a first input (41) connected to the system clock (SYS_CLK), a second input (42) connected to a test input (TEST) and with an output (43) connected to the LSSD slave latch clock input (LSSD_clk).Type: GrantFiled: November 30, 2004Date of Patent: July 15, 2008Assignee: International Business Machines CorporationInventor: Peter Verwegen
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Patent number: 6731128Abstract: A structure for testing external connections to semiconductor devices. The structure includes an external electrical path between selected external connections on the semiconductor devices.Type: GrantFiled: January 4, 2002Date of Patent: May 4, 2004Assignee: International Business Machines CorporationInventors: Gobinda Das, Franco Motika
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Patent number: 6674673Abstract: A column redundancy system including a column redundancy apparatus for performing a redundancy swapping operation of column elements within the individual micro-cells. The column redundancy apparatus further includes a fuse information storage device, a first bank address decoding mechanism decodes a read bank address corresponding to a first micro-cell accessed for a read operation, and a second bank address decoding mechanism decodes a write bank address corresponding to a second micro-cell accessed for a write operation. If there is at least one defective column element contained within the first micro-cell, then the column redundancy apparatus generates an internal column address corresponding to the at least one defective column element in the first micro-cell.Type: GrantFiled: August 26, 2002Date of Patent: January 6, 2004Assignee: International Business Machines CorporationInventors: Louis Lu-Chen Hsu, Gregory Fredeman, Chorng-Lii Hwang, Toshiaki Kirihata, Dale E. Pontius
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Patent number: 6674676Abstract: A column redundancy system including a column redundancy apparatus for performing a redundancy swapping operation of column elements within the individual micro-cells. The column redundancy apparatus further includes a fuse information storage device, a first bank address decoding mechanism decodes a read bank address corresponding to a first micro-cell accessed for a read operation, and a second bank address decoding mechanism decodes a write bank address corresponding to a second micro-cell accessed for a write operation. If there is at least one defective column element contained within the first micro-cell, then the column redundancy apparatus generates an internal column address corresponding to the at least one defective column element in the first micro-cell.Type: GrantFiled: May 23, 2003Date of Patent: January 6, 2004Assignee: International Business Machines CorporationInventors: Louis Lu-Chen Hsu, Gregory Fredeman, Chorng-Lii Hwang, Toshiaki Kirihata, Dale E. Pontius
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Patent number: 6452848Abstract: A programmable data generator for generating input test data to be applied to a semiconductor memory array is disclosed. In an exemplary embodiment of the invention, the data generator includes a programmable address scramble register which has a plurality of storage locations associated therewith. The plurality of storage locations corresponds to array address bits associated with an address generator. A first exclusive OR (XOR) logic structure is coupled to the address generator and the address scramble register, wherein the first XOR logic structure generates an address-dependent, data scramble output signal that ultimately determines a data pattern to be applied to the memory array.Type: GrantFiled: September 12, 2001Date of Patent: September 17, 2002Assignee: International Business Machines CorporationInventors: Thomas E. Obremski, Jeffrey H. Dreibelbis, Peter O. Jakobsen
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Patent number: 6347058Abstract: In many DRAM (Dynamic Random Access Memory) architectures, a sense amplifier detects and amplifies a small voltage differential between complementary bitline pairs to read from/write to a DRAM memory cell. The access speed of the DRAM is dependent on the speed of the transition, due to this amplification, of the bitline pairs from an equalized, pre-charged voltage level to final (within a given sensing cycle) high and low levels. The transition speed of the bitline pairs can be increased by providing a higher overdrive voltage to the sense amplifier. As DRAM technologies are scaled successively smaller, the overdrive voltage must be controlled to avoid compromising the reliability of the DRAM. Accordingly, the present invention relates to a DRAM circuit which provides a transiently higher overdrive voltage only during sensing. The overdrive is provided by a pre-charged capacitive source utilizing the circuit's natural capacitance.Type: GrantFiled: May 19, 2000Date of Patent: February 12, 2002Assignee: International Business Machines CorporationInventors: Russell J. Houghton, Christopher P. Miller
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Patent number: 6268908Abstract: The distribution of ultraviolet light irradiated from an illumination source to optical elements of a projection exposure device is varied by an illumination aperture. The illumination aperture is formed with a plurality of openings which may be opened or closed independently to the passage of irradiating light. The size and shape of the opening formed by the plurality of openings of the illumination aperture is determined according to the particular image to be projected.Type: GrantFiled: August 30, 1999Date of Patent: July 31, 2001Assignee: International Business Machines CorporationInventors: Orest Bula, Daniel C. Cole, Edward W. Conrad, David Vaclay Horak, Jed Hickory Rankin
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Patent number: 6222145Abstract: A method for sorting integrated circuit chips. At least one physical defect is detected in the semiconductor chips. The semiconductor chips are sorted based upon the physical defect.Type: GrantFiled: October 29, 1998Date of Patent: April 24, 2001Assignee: International Business Machines CorporationInventors: Robert F. Cook, Eric G. Liniger, Ronald L. Mendelson, Dean R. Sanders
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Patent number: 5825226Abstract: A delay equalization circuit for minimizing the static phase error in a PLL is provided. The delay equalization circuit includes an external clock signal variable delay path, and an element for creating a pulse with a width proportional to the delay of the external clock signal variable delay path. The delay equalization circuit also includes a delay path in the feedback loop, and second element for creating a second pulse in proportion to the delay of the internal delay path. Finally, the circuit contains a comparison device. The comparison device compares the first and second pulses. The comparison device outputs a difference signal in proportion to the difference in the external and internal path delays. That difference signal is fed back and used to control the external path delay such that the external delay is driven to be substantially equal to the internal delay, minimizing the static phase error of the PLL device.Type: GrantFiled: September 18, 1995Date of Patent: October 20, 1998Assignee: International Business Machines CorporationInventors: Frank D. Ferraiolo, John E. Gersbach, Ilya I. Novof
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Patent number: 5629634Abstract: An output driver circuit for a semiconductor chip has a push-pull output with a P-channel pull-up and an N-channel pull-down. Predrivers produce push-pull outputs for driving the gates of the output driver. Compensator circuits, one for the N-channel pull-down, and one for the P-channel pull-up, are used to prevent the transition from high-to-low or low-to-high from being too rapid, which could cause noise due to inductance of the package leads. A feedback circuit halts the operation of the compensator circuits after a short interval. An overvoltage circuit formed in a well of the semiconductor chip holding the driver circuit, having an input coupled to receive the data output of the predriver circuit going to the P-channel pull-up, also functions to prevent damage to the output driver circuit due to overvoltage on the output node.Type: GrantFiled: August 21, 1995Date of Patent: May 13, 1997Assignee: International Business Machines CorporationInventors: Allen R. Carl, Ronald A. Piro