Patents by Inventor Subramanian Ramesh

Subramanian Ramesh 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).

  • Patent number: 8044437
    Abstract: An improved integrated circuit cell architecture is provided for configurability between a memory cell or logic elements. The cell architecture is configured on variable layers above a first layer of metal, with the first layer of metal and layers therebelow reserved as fixed layers. By coupling a maximum of two layout cells together, a single-port or dual-port memory cell is realized. Likewise, by interconnecting transistors within a single cell or transistors among two or more cells, a logic device is realized. Within each cell, the bit lines are arranged on a layer separate from the wordlines, and extend orthogonal to each other.
    Type: Grant
    Filed: May 16, 2005
    Date of Patent: October 25, 2011
    Assignee: LSI Logic Corporation
    Inventors: Ramnath Venkatraman, Carl Anthony Monzel, III, Subramanian Ramesh
  • Patent number: 7869251
    Abstract: Disclosed is a method and device for providing fast-response One-Time-Programmable (OTP) memory based on SRAM memory technology and the inherent breakdown characteristics of a MOS transistor. Each memory cell of an SRAM memory cell circuit is connected to a programming circuit. The programming circuit is comprised of two groups of MOS transistors connected to the storage nodes (SN and SNB, where SNB is the complementary value of SN) of the two cross-coupled inverters of the SRAM memory circuit. A desired data set is loaded into the circuit and then is burned-in by applying and repeatedly cycling a “burn-in” voltage across the source and drain of the MOS transistors of the programming circuit that approaches the ON STATE trigger voltage of the characteristic bipolar junction transistor contained within the MOS transistors.
    Type: Grant
    Filed: September 26, 2008
    Date of Patent: January 11, 2011
    Assignee: LSI Corporation
    Inventors: Ramnath Venkatraman, Ruggero Castagnetti, Subramanian Ramesh
  • Publication number: 20100080035
    Abstract: Disclosed is a method and device for providing fast-response One-Time-Programmable (OTP) memory based on SRAM memory technology and the inherent breakdown characteristics of a MOS transistor. Each memory cell of an SRAM memory cell circuit is connected to a programming circuit. The programming circuit is comprised of two groups of MOS transistors connected to the storage nodes (SN and SNB, where SNB is the complementary value of SN) of the two cross-coupled inverters of the SRAM memory circuit. A desired data set is loaded into the circuit and then is burned-in by applying and repeatedly cycling a “burn-in” voltage across the source and drain of the MOS transistors of the programming circuit that approaches the ON STATE trigger voltage of the characteristic bipolar junction transistor contained within the MOS transistors.
    Type: Application
    Filed: September 26, 2008
    Publication date: April 1, 2010
    Inventors: Ramnath Venkatraman, Ruggero Castagnetti, Subramanian Ramesh
  • Patent number: 7440356
    Abstract: The present invention provides a system and method for designing and modularly expanding multiport bitcells. A modular design approach is described that reduces the complexity of designing multiport bitcells while complying with DFM rules across various semiconductor fabrication providers. The modular design may be parsed into modules such as read port modules, write port modules, and pull-up modules that may be easily interconnected to build a multiport bitcell. These modules may also be independently sized and assembled to achieve desired read margins, write margins, static noise margins as well as read access times and write times.
    Type: Grant
    Filed: July 13, 2006
    Date of Patent: October 21, 2008
    Assignee: LSI Corporation
    Inventors: Ramnath Venkatraman, Ruggero Castagnetti, Subramanian Ramesh
  • Patent number: 7404154
    Abstract: A basic cell circuit architecture having plurality of cells with fixed transistors configurable for the formation of logic devices and/or single/dual port memory devices within a structured ASIC is provided. Different configurations of ensuing integrated circuits are achieved by forming variable interconnect layers above the fixed structures. The circuit architecture can achieve interconnection of transistors within a single cell and/or across multiple cells. The interconnection can be configured to form basic logic gates as well as more complex digital and analog subsystems. In addition, each cell contains a layout of transistors that can be variably coupled to achieve a memory device, such as a SRAM device. By having the capability of forming either a logic circuit element, a memory device, or both, the circuit architecture is both memory-centric and logic-centric, and more fully adaptable to modern-day SoCs.
    Type: Grant
    Filed: July 25, 2005
    Date of Patent: July 22, 2008
    Assignee: LSI Corporation
    Inventors: Ramnath Venkatraman, Michael N. Dillon, David A. Gardner, Carl Anthony Monzel, III, Subramanian Ramesh, Robert C. Armstrong, Gary Scott Delp, Scott Allen Peterson
  • Publication number: 20080013383
    Abstract: The present invention provides a system and method for designing and modularly expanding multiport bitcells. A modular design approach is described that reduces the complexity of designing multiport bitcells while complying with DFM rules across various semiconductor fabrication providers. The modular design may be parsed into modules such as read port modules, write port modules, and pull-up modules that may be easily interconnected to build a multiport bitcell. These modules may also be independently sized and assembled to achieve desired read margins, write margins, static noise margins as well as read access times and write times.
    Type: Application
    Filed: July 13, 2006
    Publication date: January 17, 2008
    Inventors: Ramnath Venkatraman, Ruggero Castagnetti, Subramanian Ramesh
  • Patent number: 7114064
    Abstract: A system and method for accessing an Advanced Configuration and Power Interface (ACPI) namespace nodal tree in a computer platform employing an ACPI-compatible implementation is disclosed.
    Type: Grant
    Filed: November 14, 2002
    Date of Patent: September 26, 2006
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Subramanian Ramesh, Matthew Fischer
  • Patent number: 7006370
    Abstract: A memory cell architecture is provided herein for increasing memory speed, performance and robustness within a highly compact memory cell layout. Though only a few embodiments are provided herein, a feature common to all embodiments includes a novel means for sharing one or more contact structures between vertically adjacent memory cells. In particular, one or more contact structures may be shared unequally between two vertically adjacent memory cells for reducing a vertical dimension, or length, of the memory cell. Other features are disclosed for producing the highly compact memory cell layout. The various features of the present invention may be combined to produce high-performance, high-density memory arrays.
    Type: Grant
    Filed: November 18, 2003
    Date of Patent: February 28, 2006
    Assignee: LSI Logic Corporation
    Inventors: Subramanian Ramesh, Ruggero Castagnetti, Ramnath Venkatraman
  • Patent number: 7007160
    Abstract: A system and method for loading an Advanced Configuration and Power Interface (ACPI) original equipment manufacturer (OEM) description table in a computer platform employing an ACPI-compatible implementation is disclosed. In one embodiment of the system, a storage structure is operably associated with the computer platform and contains a copy of an ACPI OEM description table in a packed form. An acquirer is operable to search the storage structure fop the ACPI OEM description table and call a swapper to complete the loading of the ACPI OEM description table by issuing a signature search request.
    Type: Grant
    Filed: December 3, 2002
    Date of Patent: February 28, 2006
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Thavatchai Makphaibulchoke, Matthew Fischer, Subramanian Ramesh
  • Patent number: 7006369
    Abstract: The present invention provides a method and apparatus for reconfiguring a memory array. Aspects of the present invention include fabricating the memory array as at least one row of single-port cells up to a first metal layer. A split word line having first and second word lines is coupled to the single-port cells in each row, wherein the first word line is patterned in the first metal layer, and the second word line is patterned in a second metal layer. The split word line is further coupled to a spacer cell in the row. The method and apparatus further include programming the memory array into custom configurations based on whether the first and second word lines are connected over the spacer cell, or whether the first and second word lines are left unconnected.
    Type: Grant
    Filed: August 27, 2003
    Date of Patent: February 28, 2006
    Assignee: LSI Logic Corporation
    Inventors: Ramnath Venkatraman, Rugger Castagnetti, Subramanian Ramesh
  • Patent number: 6980462
    Abstract: An improved memory cell architecture is provided herein for reducing, or altogether eliminating, chip-level routing congestion in System-on-Chip environments. Though only a few embodiments are provided herein, features common to the described embodiments include: the formation of bitlines in a lower-level metallization layer of the memory array, and the use of word lines and ground supply lines, both formed in inter-level metallization layer(s) of the memory array, for effective shielding of the bitlines against routing signals in the chip-level routing layer.
    Type: Grant
    Filed: November 18, 2003
    Date of Patent: December 27, 2005
    Assignee: LSI Logic Corporation
    Inventors: Subramanian Ramesh, Ruggero Castagnetti, Ramnath Venkatraman
  • Patent number: 6977512
    Abstract: Test structures are provided for accurately quantifying shared contact resistance. The test structures are built based upon an actual memory cell, which is self-aligning to allow shared contact chains through an array of test cells. A main array of test cells is built to provide a chain of shared contact resistance. Using the main array of test cells, a resistance in the shared contact chain may be measured. Supplemental arrays of test cells is built to provide a chain of poly side resistance, a chain of island side resistance, a chain of island connection line resistance, and a chain of poly connection resistance. A tester measures resistance using the test structures and uses the values to accurately determine shared contact resistance.
    Type: Grant
    Filed: December 4, 2003
    Date of Patent: December 20, 2005
    Assignee: LSI Logic Corporation
    Inventors: Franklin Duan, Subramanian Ramesh, Ruggero Castagnetti
  • Patent number: 6978407
    Abstract: A self-aligning memory cell design is provided to allow testing of transistors in every cell of a memory circuit. A test array of these cells is fabricated with contact pads in each cell for specific components in the cell. Then, metal lines are provided to couple the contact pads in the test array. The whole test array is then probed via these metal lines. Tests may then be performed to detect random and systematic transistor degradation electrically for all cells in the circuit. Different components in the memory design may be tested by providing contact pads for the components of interest and providing metal lines coupling the contact pads.
    Type: Grant
    Filed: May 27, 2003
    Date of Patent: December 20, 2005
    Assignee: LSI Logic Corporation
    Inventors: Franklin L. Duan, Subramanian Ramesh, Ruggero Castagnetti
  • Patent number: 6963970
    Abstract: A system and method for implementing a fast reset of a computer system is described. In one implementation, the fast reset is implemented by adding a new ResetType to the EFIResetSystem( ) function. In particular, a third ResetType, i.e., “EfiResetFast” (FAST option), is added, which is passed as a parameter when calling the EFIResetSystem( ) function. In another implementation, the fast reset is implemented using a new EFI function, referred to herein as “EFIResetFast( )”. In either implementation, in response to a fast reset, the firmware skips several steps typically performed, including some of the core firmware construction, single cell initialization, memory testing, memory re-initialization, and partition creation, and proceeds directly to transfer of control of the platform to a software interface disposed between an OS and firmware.
    Type: Grant
    Filed: April 29, 2002
    Date of Patent: November 8, 2005
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Bradley Culter, Subramanian Ramesh, Matthew Fischer
  • Patent number: 6934174
    Abstract: A method and system for reconfiguring a memory array is disclosed. Initially, the cells in the memory array are patterned with substantially the same structure up to a predefined layer. Thereafter, the memory array is reconfigured by patterning the cells above the predefined layer such that a first plurality of cells function as memory cells, and a second plurality of cells are patterned as a dummy row or column that function as a breakpoint for the memory array.
    Type: Grant
    Filed: September 3, 2003
    Date of Patent: August 23, 2005
    Assignee: LSI Logic Corporation
    Inventors: Ruggero Castagnetti, Ramnath Venkatraman, Subramanian Ramesh
  • Publication number: 20050122120
    Abstract: Test structures are provided for accurately quantifying shared contact resistance. The test structures are built based upon an actual memory cell, which is self-aligning to allow shared contact chains through an array of test cells. A main array of test cells is built to provide a chain of shared contact resistance. Using the main array of test cells, a resistance in the shared contact chain may be measured. Supplemental arrays of test cells is built to provide a chain of poly side resistance, a chain of island side resistance, a chain of island connection line resistance, and a chain of poly connection resistance. A tester measures resistance using the test structures and uses the values to accurately determine shared contact resistance.
    Type: Application
    Filed: December 4, 2003
    Publication date: June 9, 2005
    Inventors: Franklin Duan, Subramanian Ramesh, Ruggero Castagnetti
  • Patent number: 6865614
    Abstract: Computer data is transferred from a packed to an unpacked data structure in a computer that enforces aligned memory access and for which the associated compiler lacks a compile-time directive to pack data structures. In an exemplary embodiment, the invention is employed in the pre-processing of Advanced Configuration and Power Interface (ACPI) tables stored in little-endian format for use by a big-endian operating system.
    Type: Grant
    Filed: July 2, 2001
    Date of Patent: March 8, 2005
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Matthew Fischer, Thavatchai Makphaibulchoke, Subramanian Ramesh
  • Publication number: 20050047254
    Abstract: A method and apparatus for reconfiguring a memory array is disclosed. Aspects of the present invention include fabricating the memory array as at least one row of single-port cells up to a first metal layer. A split word line having first and second word lines is coupled to the single-port cells in each row, wherein the first word line is patterned in the first metal layer, and the second word line is patterned in a second metal layer. The split word line is further coupled to a spacer cell in the row. The method and apparatus further include programming the base memory array into custom configurations based on whether the first and second word lines are connected over the spacer cell, or whether the first and second word lines are left unconnected.
    Type: Application
    Filed: August 27, 2003
    Publication date: March 3, 2005
    Inventors: Ramnath Venkatraman, Rugger Castagnetti, Subramanian Ramesh
  • Publication number: 20050047238
    Abstract: A method and system for reconfiguring a memory array is disclosed. Initially, the cells in the memory array are patterned with substantially the same structure up to a predefined layer. Thereafter, the memory array is reconfigured by patterning the cells above the predefined layer such that a first plurality of cells function as memory cells, and a second plurality of cells are patterned as a dummy row or column that function as a breakpoint for the memory array.
    Type: Application
    Filed: September 3, 2003
    Publication date: March 3, 2005
    Inventors: Ruggero Castagnetti, Ramnath Venkatraman, Subramanian Ramesh
  • Publication number: 20040243890
    Abstract: A self-aligning memory cell design is provided to allow testing of transistors in every cell of a memory circuit. A test array of these cells is fabricated with contact pads in each cell for specific components in the cell. Then, metal lines are provided to couple the contact pads in the test array. The whole test array is then probed via these metal lines. Tests may then be performed to detect random and systematic transistor degradation electrically for all cells in the circuit. Different components in the memory design may be tested by providing contact pads for the components of interest and providing metal lines coupling the contact pads.
    Type: Application
    Filed: May 27, 2003
    Publication date: December 2, 2004
    Inventors: Franklin L. Duan, Subramanian Ramesh, Ruggero Castagnetti