Patents by Inventor George McNeil Lattimore
George McNeil Lattimore 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: 6219296Abstract: A multiport memory cell having a reduced number of write wordlines is disclosed. The multiport memory cell capable of simultaneously reading data from and writing data to a storage cell comprises a storage cell for storing data, a decoder, write wordlines, write bitlines, read wordlines, and read bitlines. The write wordlines and the write bitlines are utilized to input write data into the storage cell. The read wordlines and the read bitlines are utilized to output data from the storage cell. The write bitlines are directly coupled to the storage cell, and some or all of the write wordlines are coupled to the storage cell via the decoder for the purpose of wire reduction. Similar to the write bitlines, all the read bitlines and read wordlines are directly coupled to the storage cell.Type: GrantFiled: June 20, 2000Date of Patent: April 17, 2001Assignee: International Business Machines CorporationInventors: George McNeil Lattimore, Dieter Wendel, Friedrich-Christian Wernicke
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Patent number: 6195280Abstract: A memory and a method for communicating therewith are implemented having a unidirectional write bus for writing to memory cells within a plurality of memory cell groups. Local bitlines associated with each of the memory cell groups communicate write data to the associated memory cell. Global bitlines coupled to all of the memory cells are decoupled from the local bitlines during a write operation. Following a write operation the local bitlines are restored by a precharge operation during which the global and local bitlines are also decoupled.Type: GrantFiled: March 9, 2000Date of Patent: February 27, 2001Assignee: International Business Machines CorporationInventors: George McNeil Lattimore, Younes Lotfi, Robert Anthony Ross, Jr., Gus Wai-Yan Yeung
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Patent number: 6191620Abstract: A comparator circuit (40) includes a comparator network and a comparator enabling device (80) and may be integrated with a sense amplifier circuit (41). The comparator network is adapted to receive a complementary pair of reference data signals (B, B13) and a complementary pair of analog data signals (d1, d1b). An output of the comparator circuit (40) represents a comparison of the data represented by the reference data signals and the data represented by the analog data signals. The comparator output is generated in response to a comparator enable signal (SE) applied to the comparator enabling device (80) while the input data is applied to the comparator network. The comparator enable signal (SE) is applied at a time when the analog data signals (d1, d1b) have developed a minimum differential level.Type: GrantFiled: November 4, 1999Date of Patent: February 20, 2001Assignee: International Business Machines CorporationInventors: George McNeil Lattimore, Terry Lee Leasure, Younes John Lotfi, Robert Anthony Ross, Jr., Gus Wai-Yan Yeung
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Patent number: 6157216Abstract: A silicon-on-insulator digital circuit combination having a body voltage control stage and a voltage clamp stage. The body voltage control stage is responsive to an input control signal to provide an output driver signal. The body voltage control stage has a first transistor with a terminal for electrically-coupling to a combinational logic circuit, and a body contact electrically-coupled to the input control signal such that a threshold voltage of the transistor is reduced when the transistor is placed in an active state. It can be readily appreciated that the reduced threshold voltage of the transistor increases the transition rate for the first transistor to an inactive state in response to the input control signal. The voltage clamp stage has a second transistor responsive to the input control signal such that the terminal is electrically-coupled to a reference voltage when the first transistor is in the inactive state.Type: GrantFiled: April 22, 1999Date of Patent: December 5, 2000Assignee: International Business Machines CorporationInventors: George McNeil Lattimore, Donald George Mikan, Jr., Binta Minesh Patel, Gus Wai-Yan Yeung
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Patent number: 6144609Abstract: A multiport memory cell having a reduced number of write wordlines is disclosed. The multiport memory cell capable of simultaneously reading data from and writing data to a storage cell comprises a storage cell for storing data, a decoder, write wordlines, write bitlines, read wordlines, and read bitlines. The write wordlines and the write bitlines are utilized to input write data into the storage cell. The read wordlines and the read bitlines are utilized to output data from the storage cell. The write bitlines are directly coupled to the storage cell, and some or all of the write wordlines are coupled to the storage cell via the decoder for the purpose of wire reduction. Similar to the write bitlines, all the read bitlines and read wordlines are directly coupled to the storage cell.Type: GrantFiled: July 26, 1999Date of Patent: November 7, 2000Assignee: International Business Machines CorporationInventors: George McNeil Lattimore, Dieter Wendel, Friedrich-Christian Wernicke
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Patent number: 6134164Abstract: The present invention addresses the foregoing need by providing a memory sensing circuit for accelerating a logic level transition of the complementary memory bit line of a complementary bit line pair having a full logic swing. The memory sensing circuit has a dual-rail circuit and at least one slew-rate acceleration circuit. The dual-rail circuit can be coupled across the complementary bit line pair for conditioning a signal undergoing a logical state transition placed on either of the bit lines. The at least one slew-rate acceleration circuit is coupled to the dual-rail circuit. The conditioned signal is input to the slew-rate acceleration circuit, said slew-rate acceleration circuit having an inverter circuit with an input terminal to receive the conditioned signal. A feed-back loop transistor, having a gate terminal coupled to an output terminal of the inverter circuit is responsive to an output signal placed on the output terminal such that the slew-rate of the conditioned signal is accelerated.Type: GrantFiled: April 22, 1999Date of Patent: October 17, 2000Assignee: International Business Machines Corp.Inventors: George McNeil Lattimore, Gus Wai-Yan Yeung
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Patent number: 6108255Abstract: A novel SRAM construction allows for reduced power consumption by conditionally restoring only those memory cells which are evaluated (subjected to a read or write operation). The device includes a memory array containing an arbitrary number of memory cells, a plurality of word lines, and a plurality of predecoded address lines which allow selection of one of said word lines, wherein the memory cells are arranged in groups, each group having a bit line connected thereto. A precharge circuit is connected to the bit lines, and restores a given one of the memory cells after the evaluation operation. The predecoded address lines carry encoded information regarding an address associated with the evaluated memory cell, and a decoder identifies the address to determine which of the word lines should be used to access the evaluated cell. In one embodiment, the precharge circuit is responsive to control logic associated with the address (and carried on the predecoded address lines).Type: GrantFiled: July 30, 1998Date of Patent: August 22, 2000Assignee: International Business Machines CorporationInventors: Michael Kevin Ciraula, George McNeil Lattimore, Gus Wai-Yan Yeung
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Patent number: 6081458Abstract: A memory and a method for communicating therewith are implemented having a unidirectional write bus for writing to memory cells within a plurality of memory cell groups. Local bitlines associated with each of the memory cell groups communicate write data to the associated memory cell. Global bitlines coupled to all of the memory cells are decoupled from the local bitlines during a write operation. Following a write operation the local bitlines are restored by a precharge operation during which the global and local bitlines are also decoupled.Type: GrantFiled: August 26, 1998Date of Patent: June 27, 2000Assignee: International Business Machines Corp.Inventors: George McNeil Lattimore, Younes Lotfi, Robert Anthony Ross, Jr., Gus Wai-Yan Yeung
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Patent number: 6064616Abstract: A novel SRAM construction allows for reduced power consumption by conditionally restoring only these memory cells which are evaluated (subjected to a read or write operation). The device includes a memory array containing an arbitrary number of memory cells, a plurality of word lines, and a plurality of predecoded address lines which allow selection of one of said word lines, wherein the memory cells are arranged in groups, each group having a bit line connected thereto. A precharge circuit is connected to the bit lines, and restores a given one of the memory cells after the evaluation operation. The predecoded address lines carry encoded information regarding an address associated with the evaluated memory cell, and a decoder identifies the address to determine which of the word lines should be used to access the evaluated cell. In one embodiment, the precharge circuit is responsive to control logic associated with the address (and carried on the predecoded address lines).Type: GrantFiled: July 30, 1998Date of Patent: May 16, 2000Assignee: International Business Machines CorporationInventors: Michael Kevin Ciraula, George McNeil Lattimore, Gus Wai-Yan Yeung
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Patent number: 6058065Abstract: A memory array is modified by segmenting the total length of a bitline into smaller bitline sections referred to as local bitlines. Included is an additional bitline into the array for every bitline that has been segmented. This new bitline is referred to as the global bitline. After segmentation, the array appears as several smaller sub-arrays; each sub-array has fewer cells per segmentation (local bitline) than the sum total of cells along the more traditional non-segmented bitline approach. These smaller sub-arrays (local bitline segmentations) are independent of one another and only one sub-array can be accessed per memory request (read/write). The reduced length and cell count per local bitline within each sub-array substantially reduces the total bitline capacitance (e.g., diffusion capacitance) discharged by a single memory cell during a read operation.Type: GrantFiled: May 21, 1998Date of Patent: May 2, 2000Assignee: International Business Machines CorporationInventors: George McNeil Lattimore, Terry Lee Leasure, Robert Anthony Ross, Jr., Gus Wai-Yen Yeung
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Patent number: 6046930Abstract: A column (10) of a memory array includes a plurality of memory cells (11, 12) each having first and second independent access ports (T1, T2) and a cross-coupled memory latch (20). The first access port (T1) of each memory cell (11, 12) connects a first node (21) of the latch (20) to a first bit line (14), while the second access port (T2) of each memory cell connects a second node (22) of the latch (20) to a second bit line (15). A clearing arrangement (T7) is connected to the second bit line (15) for selectively coupling the second bit line to ground. A write driver is connected to the first bit line (14) for writing data to the memory cells (11, 12) in the form of single-ended signals. A memory cell is placed in a preset condition by simultaneously coupling the second node (22) to the second bit line (15) through the second access port (T2) and coupling the second bit line to ground through the clearing arrangement (T7).Type: GrantFiled: September 1, 1998Date of Patent: April 4, 2000Assignee: International Business Machines CorporationInventors: Michael Kevin Ciraula, George McNeil Lattimore, Terry Lee Leasure, Gus Wai-Yen Yeung
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Patent number: 6025741Abstract: A circuit for conditionally restoring an execution unit in a computer processor, to reduce power consumption. Execution units, such as an arithmetic logic unit, shift/rotate unit, multiply unit, etc., have bits in transit that flow through a series of logic gates. These gates must be precharged after an operation has occurred to prepare the unit for the next operation. The conditional restore circuit evaluates either the data input to the execution unit, or the data output from the execution unit, to determine whether an operation has occurred. The precharge device for the execution is turned on only when the evaluation indicates that an operation has just occurred. The circuit includes an AND gate whose output controls the precharge device, and whose inputs include one line from the evaluation circuit, and one line for cycling (the system clock).Type: GrantFiled: December 23, 1996Date of Patent: February 15, 2000Assignee: International Business Machines CorporationInventors: Michael Kevin Ciraula, George McNeil Lattimore, Gus Wai-Yan Yeung
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Patent number: 6021512Abstract: One or more redundant sub-arrays (324) are added to a memory (316-322) of a data processing system (300) to allow a manufacturer to compensate for defects introduced during the fabrication phase of a semiconductor device upon which it is implemented. Each of these redundant sub-arrays includes a separate and independent wordline decoder (202), bitline decoder (206), and input/output circuit (208). Furthermore, the memory to which the redundant sub-array is added is typically an on-chip memory which is organized into bit-slice sub-arrays. The bit-slice organization of the memory allows the redundant sub-array to be chained together with the on-chip memory. Data-in/data-out multiplexers are used to steer bit-slices of the data around the defective sub-arrays.Type: GrantFiled: November 27, 1996Date of Patent: February 1, 2000Assignee: International Business Machines CorporationInventors: George McNeil Lattimore, Robert Paul Masleid, John Stephen Muhich
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Patent number: 6002626Abstract: A method and apparatus is provided for implementing a memory cell array having a performance-improved critical read path using a Domino boost amplifier configuration. The memory bit line is broken into small segments with a Domino boost amplifier and the bit line is connected to the input of the amplifier. The output of the amplifier drives the global bit line. The amplifier is turned "on" during a "read" and turned "off" during a "write". During a read, one memory cell within one array segment is turned on. The memory cell drives the differential signal on to the local bit line pair. Also during a read, the boost amplifier which attaches to that local bit line is enabled. The boost amplifier amplifies the input signal (local bit line pair) and drives that signal on to the global bit line. Since the bit line is broken into small segments with boost amplifiers, there are many boost amplifiers attached on the global bit line.Type: GrantFiled: August 1, 1997Date of Patent: December 14, 1999Assignee: International Business Machines CorporationInventors: George McNeil Lattimore, Robert Anthony Ross, Jr., Gus Wai-Yen Yeung
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Patent number: 5982692Abstract: A method and apparatus is provided for implementing a memory cell array having a performance-improved critical read path using a boost amplifier configuration. The memory bit line is broken into small segments with a boost amplifier and the bit line is connected to the input of the amplifier. The output of the amplifier drives the global bit line. The amplifier is turned "on" during a "read" and turned "off" during a "write". During a read, one memory cell within one array segment is turned on. The memory cell drives the differential signal on to the local bit line pair. Also during a read, the boost amplifier which attaches to that local bit line is enabled. The boost amplifier amplifies the input signal (local bit line pair) and drives that signal on to the global bit line. Since the bit line is broken into small segments with boost amplifiers, there are many boost amplifiers attached on the global bit line.Type: GrantFiled: August 1, 1997Date of Patent: November 9, 1999Assignee: International Business Machines CorporationInventors: George McNeil Lattimore, Robert Anthony Ross, Jr., Gus Wai-Yen Yeung
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Patent number: 5963486Abstract: A bit switch circuit (10) includes an amplifier stage (11) and a plurality of input stages (23,33,43,53). Each input stage (23,33,43,53) is connected to receive as inputs the signals applied to a bit line pair associated with a memory array. Each input stage (23,33,43,53) is also associated with a common node (24,34,44,54), and a select transistor (T4, T5, T6, T7). Each select transistor (T4, T5, T6, T7) responds to a select input signal to couple the respective common node (24,34,44,54) to ground. This allows the sense amplifier (11) to respond to the data signals on the bit line pair (20,21,30,31,40,41,50,51) associated with the respective input stage (23,33,43,53).Type: GrantFiled: June 19, 1998Date of Patent: October 5, 1999Assignee: International Business Machines CorporationInventors: Gus Wai-Yen Yeung, Robert Anthony Ross, Jr., George McNeil Lattimore
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Patent number: 5956286Abstract: The data processing system of the present invention implements a multi-port memory cell, wherein the port functions are divided based on a timing cycle in which they may be accessed. For example, in one case, a first port may be utilized only for read operations and accessed only during a first portion of the timing cycle. Similarly, a second port may be used for read or write operations and may be accessed only during a second portion of the timing cycle. To ensure that the multi-port memory cell functions correctly, both ports should not be accessed simultaneously. A circuit and method are implemented to ensure that both ports are not accessed simultaneously by implementing a delay function in a unique and useful manner.Type: GrantFiled: October 28, 1997Date of Patent: September 21, 1999Assignee: International Business Machines CorporationInventors: George McNeil Lattimore, Robert Anthony Ross, Jr., Mithkal Moh'd Smadi
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Patent number: 5953745Abstract: A set associative cache memory array includes redundant memory portions for use in the case of a defective portion of the memory. Information is stored within the defective portion of the memory array and an identical copy is stored within the redundant portion. Additionally, reading of the information is done from both the defective portion and the redundant portion. Selection of the information from either the defective portion or the redundant portion is made using programmable circuitry such as a fuse.Type: GrantFiled: November 27, 1996Date of Patent: September 14, 1999Assignee: International Business Machines CorporationInventors: George McNeil Lattimore, Terry Lee Leasure, Gus Wai-Yan Yeung
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Patent number: 5907508Abstract: The data processing system of the present invention implements a multi-port memory cell and control therefor. In response to a single clock signal, the cell is accessed during multiple, non-concurrent intervals during a single clock cycle. Each of the accesses during the clock cycle are over a different line.Type: GrantFiled: October 28, 1997Date of Patent: May 25, 1999Assignee: International Business Machines CorporationInventors: George McNeil Lattimore, Robert Anthony Ross, Jr., Mithkal Moh'd Smadi
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Patent number: 5896399Abstract: The present invention applies a Static Evaluate technique to a memory array in a selective manner that allows some parts of the array to use the technique, and yet keeps the array area and timing unaffected for normal operation. The present invention allows the decode functions of the memory array to become pseudo-static during a first part of a clock cycle. In addition, if a write function is being performed, the write data is also held pseudo-static and is not written until a second part of a clock cycle when all addresses and data have stabilized. The invention can be used for system debug, product bring-up, or burn-in, even if there are non-functional race paths.Type: GrantFiled: December 11, 1996Date of Patent: April 20, 1999Assignee: International Business Machines CorporationInventors: George McNeil Lattimore, Michael Kevin Ciraula, Dieter F. Wendel, Manoj Kumar, Friedrich-Christian Wernicke