Patents by Inventor Rajiv V. Joshi
Rajiv V. Joshi 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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Publication number: 20030191991Abstract: A row redundancy system is provided for replacing faulty wordlines of a memory array having a plurality of banks. The row redundancy system includes a remote fuse bay storing at least one faulty address corresponding to a faulty wordline of the memory array; a row fuse array for storing row fuse information corresponding to at least one bank of the memory array; and a copy logic module for copying at least one faulty address stored in the remote fuse bay into the row fuse array; wherein the copy logic module is programmed to copy the at least one faulty address into the row fuse information stored in the row fuse array corresponding to a predetermined number of banks in accordance with a selectable repair field size.Type: ApplicationFiled: April 3, 2002Publication date: October 9, 2003Applicant: International Business Machines CorporationInventors: Louis L. Hsu, Gregory J. Fredeman, Rajiv V. Joshi, Toshiaki Kirihata
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Patent number: 6631503Abstract: The present invention provides a temperature programmable timing delay system utilizing circuitry for generating a band-gap reference and for sensing the on-chip temperature of an integrated circuit chip. The circuitry outputs the sensed temperature as a binary output which is received by a programmable table circuit of the timing delay system. The programmable table circuit outputs a binary output corresponding to the received binary output. The timing delay system further includes a temperature dependent timing delay circuit having inputs for receiving the binary output of the programmable table circuit and an output for outputting a timing delay signal for delaying a clock by a timing delay corresponding to the binary output of the programmable table circuit. The band-gap reference can be a temperature independent band-gap reference voltage having a constant-voltage value or a temperature dependent band-gap reference current having a constant-current value.Type: GrantFiled: January 5, 2001Date of Patent: October 7, 2003Assignee: IBM CorporationInventors: Louis L. Hsu, Rajiv V. Joshi, John A. Fifield
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Patent number: 6624459Abstract: Silicon on insulator (SOI) field effect transistors (FET) with a shared body contact, a SRAM cell and array including the SOI FETs and the method of forming the SOI FETs. The SRAM cell has a hybrid SOI/bulk structure wherein the source/drain diffusions do not penetrate to the underlying insulator layer, resulting in a FET in the surface of an SOI layer with a body or substrate contact formed at a shared contact. FETs are formed on SOI silicon islands located on a BOX layer and isolated by shallow trench isolation (STI). NFET islands in the SRAM cells include a body contact to a P-type diffusion in the NFET island. Each NFET in the SRAM cells include at least one shallow source/drain diffusion that is shallower than the island thickness. A path remains under the shallow diffusions between NFET channels and the body contact. The P-type body contact diffusion is a deep diffusion, the full thickness of the island. Bit line diffusions shared by SRAM cells on adjacent wordlines may be deep diffusions.Type: GrantFiled: April 12, 2000Date of Patent: September 23, 2003Assignee: International Business Machines Corp.Inventors: William R. Dachtera, Rajiv V. Joshi, Werner A. Rausch
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Patent number: 6617702Abstract: The present invention provides for globally aligning microelectronic circuit systems, such as communication devices and chips, fabricated on or bonded to the front and back sides of one or more substrates to provide for wireless communications between the circuit systems through the one or more substrates. In one embodiment, two circuit systems situated on opposite sides of a substrate are aligned to provide for wireless communications between the two circuit systems through the substrate. In another embodiment, communication devices situated on one or more substrates are aligned to provide for wireless communications between the communication devices through the one or more substrates. In another embodiment, two chips situated on opposite sides of a transparent substrate are aligned to provide for wireless communications between the two chips through the transparent substrate.Type: GrantFiled: January 25, 2001Date of Patent: September 9, 2003Assignee: IBM CorporationInventors: Louis L. Hsu, Rajiv V. Joshi, Carl Radens, Jack A. Mandelman, Tsorng-Dih Yuan
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Publication number: 20030147272Abstract: An SRAM system is provided having an array of SRAM cells receiving a first power voltage. The SRAM system includes at least one circuit receiving a first power voltage, and a power control circuit for supplying a second power voltage to at least one selected circuit of the at least one circuit of the system. The system is one of a memory array and a logic system, and a circuit of the at least one circuit is one of a memory cell of the memory array, a sense amplifier of the memory array and a path of the logic system. Furthermore, a method is provided for providing a power supply voltage to at least one circuit of a system. The method includes the steps of providing a first power supply voltage to the at least one circuit of the system, and providing a second power supply voltage to at least one selected circuit of the at least one circuit.Type: ApplicationFiled: February 5, 2002Publication date: August 7, 2003Applicant: International Business Machines CorporationInventors: Rajiv V. Joshi, Louis L. Hsu, Azeez J. Bhavnagarwala
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Publication number: 20030142558Abstract: A self-timed data communication system for a wide data width semiconductor memory system having a plurality of data paths is provided. The data communication system includes a central data path including at least one junction circuit configured for exchanging data signals between the central data path and the plurality of data paths of the at least one data path. A respective one junction circuit of the at least one junction circuit includes circuitry for controlling resetting the respective one junction circuit for preparation of a subsequent data transfer through the respective one junction circuit in accordance with receipt of an input junction monitor signal indicating that data has been transferred to the respective one junction circuit. The data communication system further includes a plurality of data banks configured for storing data, wherein a corresponding data bank of the plurality of data banks is connected to a respective one data path of the plurality of data paths.Type: ApplicationFiled: January 31, 2002Publication date: July 31, 2003Applicant: International Business Machines CorporationInventors: Louis L. Hsu, Rajiv V. Joshi, Jeremy K. Stephens, Daniel Storaska
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Publication number: 20030128573Abstract: A timing system for controlling timing of data transfers within a semiconductor memory system is provided. The timing system includes a programming circuit for generating a bias signal, wherein the bias signal is biased in accordance with an incoming data transfer address corresponding to a memory address of the memory system, and a delay module for receiving the bias signal and generating an output clock signal, wherein the output clock signal is delayed in accordance with the bias signal.Type: ApplicationFiled: January 9, 2002Publication date: July 10, 2003Applicant: International Business Machines CorporationInventors: Louis L. Hsu, Rajiv V. Joshi
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Publication number: 20030123522Abstract: A combined low-voltage, low-power band-gap reference and temperature sensor circuit is provided for providing a band-gap reference parameter and for sensing the temperature of a chip, such as an eDRAM memory unit or CPU chip, using the band-gap reference parameter. The combined sensor circuit is insensitive to supply voltage and a variation in the chip temperature. The power consumption of both circuits, i.e., the band-gap reference and the temperature sensor circuits, encompassing the combined sensor circuit is less than one &mgr;W. The combined sensor circuit can be used to monitor local or global chip temperature. The result can be used to (1) regulate DRAM array refresh cycle time, e.g., the higher the temperature, the shorter the refresh cycle time, (2) to activate an on-chip or off-chip cooling or heating device to regulate the chip temperature, (3) to adjust internally generated voltage level, and (4) to adjust the CPU (or microprocessor) clock rate, i.e., frequency, so that the chip will not overheat.Type: ApplicationFiled: January 15, 2003Publication date: July 3, 2003Inventors: Louis L. Hsu, Rajiv V. Joshi, Russell J. Houghton
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Patent number: 6574127Abstract: A dataline wiring structural system is provided for an eDRAM which suppresses coupling and switching noise associated with datalines by providing a plurality of metal levels upon which the datalines are positioned. Each of the datalines carrying a differential signal includes at least one vertical twist in which the true and complementary signal components of the differential signal change position from the one metal level of the plurality of metal levels to another level.Type: GrantFiled: March 29, 2001Date of Patent: June 3, 2003Assignee: IBM CorporationInventors: Louis L. Hsu, Rajiv V. Joshi, David R. Hanson
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Patent number: 6563736Abstract: A flash memory array having a plurality of bitlines, at least one wordline and a plurality of flash memory flash memory elements, wherein each flash memory element includes two transistors for storing two bits, and wherein each flash memory element is positioned between a pair of adjacent bitlines. A method is also presented for fabricating the flash memory array having the plurality of flash memory elements, wherein each flash memory element is configured for storing two bits.Type: GrantFiled: May 18, 2001Date of Patent: May 13, 2003Assignee: IBM CorporationInventors: Louis L. Hsu, Rajiv V. Joshi, Carl Radens, Jack A. Mandelman, William R. Tonti
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Patent number: 6552398Abstract: A T-RAM array having a planar cell structure is presented which includes a plurality of T-RAM cells. Each of the plurality of T-RAM cells is fabricated by using doped polysilicon to form a self-aligned diffusion region to create a low-contact resistance p+ diffusion region. A silicided p+ polysilicon wire is preferably used to connect each of the plurality of the T-RAM cells to a reference voltage Vref. A self-aligned junction region is formed between every two wordlines by implanting a n+ implant into a gap between every two wordlines. The self-aligned junction region provides for a reduction in the T-RAM cell size from a cell size of 8F2 for a prior art T-RAM cell to a cell size of less than or equal to 6F2. Preferably, the T-RAM array is built on a semiconductor silicon-on-insulator (SOI) wafer to reduce junction capacitance and improve scalability.Type: GrantFiled: January 16, 2001Date of Patent: April 22, 2003Assignee: IBM CorporationInventors: Louis L. Hsu, Rajiv V. Joshi, Fariborz Assaderaghi
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Patent number: 6549450Abstract: The present invention provides an SOI SRAM architecture system which holds all the bitlines at a lower voltage level, for example, ground, or a fraction of Vdd, during array idle or sleep mode. Preferably, the bitlines are held at a voltage level approximately equal to Vdd minus Vth, where Vth represents the threshold voltage of the transfer devices of the SRAM cells. This prevents the body regions of the transfer devices of each cell of the array from fully charging up, and thus the system avoids the parasitic bipolar leakage current effects attributed to devices fabricated on a partially-depleted SOI substrate. Also, during idle or sleep mode, if all the bitlines are kept at about the Vdd minus Vth voltage level, power consumption by the SRAM architecture system is decreased. This is because the leakage path via one of the transfer gates of all the SRAM cells is greatly minimized.Type: GrantFiled: November 8, 2000Date of Patent: April 15, 2003Assignee: IBM CorporationInventors: Louis L. Hsu, Rajiv V. Joshi, Fariborz Assaderaghi, Mary J. Saccamango
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Patent number: 6545935Abstract: A dual-port, folded-bitline DRAM architecture system is presented which prioritizes two simultaneous access requests slated for a DRAM cell of a data array prior to performing at least one of the access requests to prevent affecting the integrity of the data while suppressing noise due to wordline-to-bitline coupling, bitline-to-bitline coupling, and bitline-to-substrate coupling. If the two access requests are write-read, the system prioritizes the two access requests as being equal to each other. The system then simultaneously performs the write and read access by accessing the corresponding DRAM cell through the first port to write the data while simultaneously writing the data through to an output bus, which is equivalent to a read access. In another embodiment of the present invention, a dual-port, shared-address bus DRAM architecture system is presented which also prioritizes two simultaneous access requests slated for the DRAM cell of a data array.Type: GrantFiled: August 29, 2000Date of Patent: April 8, 2003Assignee: IBM CorporationInventors: Louis L. Hsu, Rajiv V. Joshi, Radens Carl
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Patent number: 6531911Abstract: A combined low-voltage, low-power band-gap reference and temperature sensor circuit is provided for providing a band-gap reference parameter and for sensing the temperature of a chip, such as an eDRAM memory unit or CPU chip, using the band-gap reference parameter. The combined sensor circuit is insensitive to supply voltage and a variation in the chip temperature. The power consumption of both circuits, i.e., the band-gap reference and the temperature sensor circuits, encompassing the combined sensor circuit is less than one &mgr;W. The combined sensor circuit can be used to monitor local or global chip temperature. The result can be used to (1) regulate DRAM array refresh cycle time, e.g., the higher the temperature, the shorter the refresh cycle time, (2) to activate an on-chip or off-chip cooling or heating device to regulate the chip temperature, (3) to adjust internally generated voltage level, and (4) to adjust the CPU (or microprocessor) clock rate, i.e., frequency, so that the chip will not overheat.Type: GrantFiled: July 7, 2000Date of Patent: March 11, 2003Assignee: IBM CorporationInventors: Louis L. Hsu, Rajiv V. Joshi, Russell J. Houghton
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Publication number: 20030034825Abstract: An integrated circuit system having a plurality of macros is provided. The integrated circuit system includes an external voltage supply input configured for supplying an external voltage to the integrated circuit; and a plurality of internal voltage supply generators, each of the plurality of internal voltage supply generators being connected to a respective macro of the plurality of macros and configured for receiving the external voltage via the external voltage supply input for generating an internal voltage supply for operating its respective macro. Each of the plurality of internal voltage supply generators includes circuitry for generating the internal voltage supply and circuitry for disconnecting at least a portion of its respective macro. The integrated circuit system can be applied to a semiconductor chip to save active or stand-by power. It can also be used to disconnect a defective portion of the chip and optionally replace it with a non-defective portion of the chip.Type: ApplicationFiled: August 14, 2001Publication date: February 20, 2003Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Louis L. Hsu, Rajiv V. Joshi, Chorng-Lii Hwang, Toshiaki K. Kirihata, Paul C. Parries
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Patent number: 6507237Abstract: A low-voltage, low-power DC voltage generator system is provided having two negative voltage pump circuits for generating voltages for operating negative wordline and substrate bias charge pump circuits, a reference generator for generating a reference voltage, and a two-stage cascaded positive pump system having a first stage pump circuit and a second stage pump circuit. The first stage converts a supply voltage to a higher voltage level, e.g., one volt to 1.5 volts, to be used for I/O drivers, and the second stage converts the output voltage from the first stage to a higher voltage level, e.g., from 1.5 volts to about 2.5 volts, for operating a boost wordline charge pump circuit. The DC voltage generator system further includes a micro pump circuit for providing a voltage level which is greater than one-volt to be used as reference voltages, even when an operating voltage of the DC voltage generator system is at or near one-volt.Type: GrantFiled: January 3, 2002Date of Patent: January 14, 2003Assignee: IBM CorporationInventors: Louis L. Hsu, Rajiv V. Joshi, Russell J. Houghton, Wayne F. Ellis, Jeffrey H. Dreibelbis
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Publication number: 20030006803Abstract: A MOSFET logic circuit for performing a logic OR operation is presented including three transistors, wherein at least two input signals are provided to the circuit and an output signal indicative of an OR operation performed on a first and second input signal of the at least two input signals is output from the circuit.Type: ApplicationFiled: July 6, 2001Publication date: January 9, 2003Applicant: International Business Machines CorporationInventors: Rajiv V. Joshi, Ruchir Puri
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Patent number: 6504204Abstract: The present invention provides a process integration technique which significantly reduces the array size of dual-port DRAM architecture systems. The array is reduced to a size which is significantly smaller than the array size of prior art DRAM architecture systems by using bitlines formed at half-pitch. The present invention also provides dual-port, open-bitline and folded-bitline DRAM arrays where each DRAM cell in the array has at least two vertically-oriented devices therein.Type: GrantFiled: October 21, 2000Date of Patent: January 7, 2003Assignee: IBM CorporationInventors: Louis L. Hsu, Rajiv V. Joshi, Radens Carl
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Publication number: 20020190265Abstract: A T-RAM array having a plurality of T-RAM cells is presented where each T-RAM cell has dual devices. Each T-RAM cell is planar and has a buried vertical thyristor and a horizontally stacked pseudo-TFT transfer gate. The buried vertical thyristor is located beneath the horizontally stacked pseudo-TFT transfer gate. A method is also presented for fabricating the T-RAM array having the buried vertical thyristors, the horizontally stacked pseudo-TFT transfer gates and the planar cell structure.Type: ApplicationFiled: June 13, 2001Publication date: December 19, 2002Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Louis L. Hsu, Rajiv V. Joshi, Fariborz Assaderaghi
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Publication number: 20020188797Abstract: A unified SRAM cache system is provided incorporated several SRAM macros of an embedded DRAM (eDRAM) system and their functions. Each incorporated SRAM macro can be independently accessed without interfering with the other incorporated SRAM macros within the unified SRAM cache system. The incorporated SRAM macros share a single set of support circuits, such as row decoders, bank decoders, sense amplifiers, wordline drivers, bank pre-decoders, row pre-decoders, I/O drivers, multiplexer switch circuits, and data buses, without compromising the performance of the eDRAM system.Type: ApplicationFiled: June 12, 2001Publication date: December 12, 2002Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Louis L. Hsu, Rajiv V. Joshi