Patents by Inventor Srinivas T. Reddy

Srinivas T. Reddy 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: 6344755
    Abstract: A programmable logic device is provided that allows a redundant row of programmable logic to be shifted into place to repair the device when a defect is detected in a row of programmable logic on the device. The redundant row is shifted into place by routing programming data into the normal logic and the redundant logic while bypassing the row of logic containing the defect. Switching circuitry may be used to direct programming data into the serial inputs of various data registers that are then used to load the programming data into the device. The patterns of programmable connections that are made between programmable logic regions on the device and vertical and horizontal conductors also allow redundant logic to be shifted into place. Some connections between the logic and the horizontal and vertical conductors may be identical within a column to facilitate shifting. Other connections may only partially overlap between respective rows.
    Type: Grant
    Filed: October 18, 2000
    Date of Patent: February 5, 2002
    Assignee: Altera Corporation
    Inventors: Srinivas T. Reddy, Manuel Mejia, Andy L. Lee, Bruce B. Pedersen
  • Patent number: 6337578
    Abstract: Redundant circuitry is provided for a programmable logic device that uses an interleaved input multiplexer circuit arrangement. The programmable logic device has at least one row of logic regions and has multiple columns, each of which contains one of the interleaved input multiplexers and one of the logic regions. A set of conductors associated with the row of logic regions is used to convey signals between the logic regions. Each interleaved logic region distributes logic signals from the conductors in the row to two adjacent logic regions. Bypass circuitry is provided in each column for bypassing the interleaved input multiplexer and logic region in that column. If a defect is detected in a column during testing of the device, the manufacturer can repair the device using the bypass circuitry to bypass that column. Spare logic is provided to replace the circuitry lost when a defective column is bypassed.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: January 8, 2002
    Assignee: Altera Corporation
    Inventors: David E. Jefferson, Srinivas T. Reddy
  • Patent number: 6335634
    Abstract: Programmable interconnection group arrangements for selectively interconnecting logic on a programmable logic device are provided. Interconnection groups may be programmed to route signals between the various conductors on the device, and to route signals from various logic regions on the device to the various conductors. The interconnection groups provide routing flexibility and efficiency without using excessive amounts of interconnection resources.
    Type: Grant
    Filed: May 22, 2000
    Date of Patent: January 1, 2002
    Inventors: Srinivas T. Reddy, Ketan Zaveri, Christopher F. Lane, Andy L. Lee, Cameron R. McClintock, Bruce B. Pedersen, Manuel Mejia, Richard G. Cliff
  • Patent number: 6323677
    Abstract: In order to facilitate the performance of multiplications in programmable logic devices, individual logic modules of such devices are constructed so that one logic module can perform (at least) both one place of binary multiplication and one place of full binary addition. This makes it possible to reduce the number of logic modules that are required to perform a multiplication. It also reduces the number of inter-module connections employed in a multiplication, thereby tending to decrease the time required to perform a multiplication.
    Type: Grant
    Filed: April 4, 2000
    Date of Patent: November 27, 2001
    Assignee: Altera Corporation
    Inventors: Christopher F. Lane, Srinivas T. Reddy, Richard G. Cliff, Ketan H. Zaveri, Bruce B. Pedersen, Kerry Veenstra
  • Patent number: 6300794
    Abstract: A programmable logic device has a plurality of super-regions of programmable logic disposed on the device in a two-dimensional array of intersecting rows and columns of super-regions. Horizontal and vertical inter-super-region interconnection conductors are associated with each row and column, respectively. Each super-region includes a plurality of regions of programmable logic, and each region includes a plurality of subregions of programmable logic. Inter-region interconnection conductors are associated with each super-region, principally for bringing signals into the super-region and interconnecting the regions in the super-region. Local conductors are associated with each region, principally for bringing signals into the region. At the super-region level the device may be horizontally and vertically isomorphic, which helps make it possible to produce devices with low aspect ratios of one or nearly one. Shared driver circuits may be provided (e.g.
    Type: Grant
    Filed: January 20, 2000
    Date of Patent: October 9, 2001
    Assignee: Altera Corporation
    Inventors: Srinivas T. Reddy, Richard G. Cliff, Christopher F. Lane, Ketan H. Zaveri, Manuel M. Mejia, David Jefferson, Bruce B. Pedersen, Andy L. Lee
  • Publication number: 20010022519
    Abstract: A programmable logic array integrated circuit device has a plurality of regions of programmable logic disposed on the device in a two-dimensional array of intersecting rows and columns of regions. The output signals of several regions share a group of drivers for applying region output signals to interconnection conductors that convey signals between regions. This conserves driver resources and increases signal routing flexibility. Various approaches can be used for configuring the interconnection conductors to also conserve interconnection conductor resources. Logic regions may be used to directly drive specific input/output cells, thereby simplifying signal routing to the I/O cells and also possibly simplifying the structure of the I/O cells (e.g., by allowing certain I/O cell functions to be performed in the associated logic region).
    Type: Application
    Filed: May 25, 2001
    Publication date: September 20, 2001
    Applicant: Altera Corporation
    Inventors: Richard G. Cliff, Francis B. Heile, Joseph Huang, Christopher F. Lane, Fung Fung Lee, Cameron McClintock, David W. Mendel, Ninh D. Ngo, Bruce B. Pedersen, Srinivas T. Reddy, Chiakang Sung, Kerry Veenstra, Bonnie I. Wang
  • Patent number: 6288970
    Abstract: A programmable logic device memory array circuit is provided that contains a pair of associated combinable single-port memory arrays. The memory array circuit may have a variable depth and width. The combinable single-port memory arrays may be operated independently if desired. Alternatively, a pair of the combinable single-port memory arrays can be combined to form a dual-port memory array. When the single-port memory arrays are combined to form a dual-port memory array, circuitry from a first of the combinable singleport memory arrays is used to perform writing operations and circuitry from a second of the combinable single-port memory arrays is used to perform reading operations. The availability of the dual-port memory array capability allows users to implement circuits such as first-in-first-out buffers and other circuits that require the ability to perform concurrent read and write operations.
    Type: Grant
    Filed: June 30, 1998
    Date of Patent: September 11, 2001
    Assignee: Altera Corporation
    Inventors: Srinivas T. Reddy, Christopher F. Lane, Manuel Mejia
  • Publication number: 20010015933
    Abstract: A dual-port programmable logic device memory array is provided. Selectable-size data words may be written to and read from the array concurrently. Data is written into the array using write column decoder and data selection logic. The size of the data words handled by the write column decoder and data selection logic is controlled by mode select signals. Data is read from the array using read column decoder and data selection logic. The size of the data words handled by the read column decoder and data selection logic is also controlled by mode select signals. The write column decoder and data selection logic may be used to write data into the memory array at one selected location at the same time that the read column decoder and data selection logic is used to read data from the array at another selected location. A write row address decoder and a read row address decoder are used to independently address individual rows of memory cells in the memory array during writing and reading, respectively.
    Type: Application
    Filed: December 21, 2000
    Publication date: August 23, 2001
    Applicant: Altera Corporation
    Inventors: Srinivas T. Reddy, Christopher F. Lane, Manuel Mejia, Richard G. Cliff, Kerry Veenstra
  • Publication number: 20010006347
    Abstract: Redundant circuitry is provided for a programmable logic device that uses an interleaved input multiplexer circuit arrangement. The programmable logic device has at least one row of logic regions and has multiple columns, each of which contains one of the interleaved input multiplexers and one of the logic regions. A set of conductors associated with the row of logic regions is used to convey signals between the logic regions. Each interleaved logic region distributes logic signals from the conductors in the row to two adjacent logic regions. Bypass circuitry is provided in each column for bypassing the interleaved input multiplexer and logic region in that column. If a defect is detected in a column during testing of the device, the manufacturer can repair the device using the bypass circuitry to bypass that column. Spare logic is provided to replace the circuitry lost when a defective column is bypassed.
    Type: Application
    Filed: February 28, 2001
    Publication date: July 5, 2001
    Applicant: Altera Corporation
    Inventors: David E. Jefferson, Srinivas T. Reddy
  • Publication number: 20010006348
    Abstract: A programmable logic device has a plurality of super-regions of programmable circuitry disposed on the device in a two-dimensional array of such super-regions. Each super-region includes a plurality of regions of programmable logic and a region of programmable memory. Each logic region includes a plurality of subregions of programmable logic. Each super-region has associated interconnection resources for allowing communication between the logic and memory regions of that super-region without the need to use, for such relatively local interconnections, the longer-length inter-super-region interconnection resources that are also provided on the device.
    Type: Application
    Filed: February 23, 2001
    Publication date: July 5, 2001
    Applicant: Altera Corporation
    Inventors: David E. Jefferson, Cameron McClintock, James Schleicher, Andy L. Lee, Manuel Mejia, Bruce B. Pedersen, Christopher F. Lane, Richard G. Cliff, Srinivas T. Reddy
  • Patent number: 6225822
    Abstract: A programmable logic integrated circuit device has a plurality of areas of programmable logic disposed on the device in a two-dimensional array of intersecting rows and columns of such areas. A so-called “fast conductor” network is provided on the device for rapidly and efficiently distributing a relatively small number of signals to substantially any logic area on the device. The fast conductor network has several main conductors that substantially bisect the array in one direction (e.g., by extending parallel to the column axis). Some main conductors can carry signals from off the device. Other main conductors can carry signals generated on the device. The network further includes secondary conductors that extend transverse to the main conductors (e.g., along each row of logic areas). Programmable logic connectors are provided for selectively applying signals from the main conductors to the secondary conductors and from the secondary conductors to the logic areas.
    Type: Grant
    Filed: April 6, 1999
    Date of Patent: May 1, 2001
    Assignee: Altera Corporation
    Inventors: Christopher F. Lane, Srinivas T. Reddy
  • Patent number: 6225823
    Abstract: A programmable logic device has a plurality of conductors extending around its periphery for use in providing at least some of the signals needed for control of input/output (“I/O”) pins which are also disposed around the periphery of the device. These control signals may include clock signals, output enable signals, clock enable signals, clear signals, or the like. The conductors that thus extend around the periphery are segmented into plural segments that can either be used independently of one another or programmably stitched together and therefore used together.
    Type: Grant
    Filed: March 24, 2000
    Date of Patent: May 1, 2001
    Assignee: Altera Corporation
    Inventors: Christopher F. Lane, Srinivas T. Reddy, Andy L. Lee, David Edward Jefferson
  • Patent number: 6222382
    Abstract: Redundant circuitry is provided for a programmable logic device that uses an interleaved input multiplexer circuit arrangement. The programmable logic device has at least one row of logic regions and has multiple columns, each of which contains one of the interleaved input multiplexers and one of the logic regions. A set of conductors associated with the row of logic regions is used to convey signals between the logic regions. Each interleaved logic region distributes logic signals from the conductors in the row to two adjacent logic regions. Bypass circuitry is provided in each column for bypassing the interleaved input multiplexer and logic region in that column. If a defect is detected in a column during testing of the device, the manufacturer can repair the device using the bypass circuitry to bypass that column. Spare logic is provided to replace the circuitry lost when a defective column is bypassed.
    Type: Grant
    Filed: March 17, 2000
    Date of Patent: April 24, 2001
    Assignee: Altera Corporation
    Inventors: David E. Jefferson, Srinivas T. Reddy
  • Patent number: 6215326
    Abstract: A programmable logic device has a plurality of super-regions of programmable circuitry disposed on the device in a two-dimensional array of such super-regions. Each super-region includes a plurality of regions of programmable logic and a region of programmable memory. Each logic region includes a plurality of subregions of programmable logic. Each super-region has associated interconnection resources for allowing communication between the logic and memory regions of that super-region without the need to use, for such relatively local interconnections, the longer-length inter-super-region interconnection resources that are also provided on the device.
    Type: Grant
    Filed: March 10, 1999
    Date of Patent: April 10, 2001
    Assignee: Altera Corporation
    Inventors: David E. Jefferson, Cameron McClintock, James Schleicher, Andy L. Lee, Manuel Mejia, Bruce B. Pedersen, Christopher F. Lane, Richard G. Cliff, Srinivas T. Reddy
  • Patent number: 6201404
    Abstract: A programmable logic device is provided that allows a redundant row of programmable logic to be shifted into place to repair the device when a defect is detected in a row of programmable logic on the device. The redundant row is shifted into place by routing programming data into the normal logic and the redundant logic while bypassing the row of logic containing the defect. Switching circuitry may be used to direct programming data into the serial inputs of various data registers that are then used to load the programming data into the device. The patterns of programmable connections that are made between programmable logic regions on the device and vertical and horizontal conductors also allow redundant logic to be shifted into place. Some connections between the logic and the horizontal and vertical conductors may be identical within a column to facilitate shifting. Other connections may only partially overlap between respective rows.
    Type: Grant
    Filed: April 20, 1999
    Date of Patent: March 13, 2001
    Assignee: Altera Corporation
    Inventors: Srinivas T. Reddy, Manuel Mejia, Andy L. Lee, Bruce B. Pedersen
  • Patent number: 6191998
    Abstract: A programmable logic device memory array circuit is provided that contains a pair of associated combinable single-port memory arrays. The memory array circuit may have a variable depth and width. The combinable single-port memory arrays may be operated independently if desired. Alternatively, a pair of the combinable single-port memory arrays can be combined to form a dual-port memory array. When the single-port memory arrays are combined to form a dual-port memory array, circuitry from a first of the combinable single-port memory arrays is used to perform writing operations and circuitry from a second of the combinable single-port memory arrays is used to perform reading operations. The availability of the dual-port memory array capability allows users to implement circuits such as first-in-first-out buffers and other circuits that require the ability to perform concurrent read and write operations.
    Type: Grant
    Filed: December 1, 1999
    Date of Patent: February 20, 2001
    Assignee: Altera Corporation
    Inventors: Srinivas T. Reddy, Christopher F. Lane, Manuel Mejia
  • Patent number: 6191608
    Abstract: Programmable logic array devices are programmed from programming devices in networks that facilitate programming any number of such logic devices with programs of any size or complexity. The source of programming data and control may be a microprocessor or one or more serial EPROMs, one EPROM being equipped with a clock circuit. Several parallel data streams may be used to speed up the programming operation. A clock circuit with a programmably variable speed may be provided to facilitate programming logic devices with different speed characteristics. The programming protocol may include an acknowledgment from the logic device(s) to the programming data source after each programming data transmission so that the source can automatically transmit programming data at the speed at which the logic device is able to accept that data.
    Type: Grant
    Filed: May 5, 1997
    Date of Patent: February 20, 2001
    Assignee: Altera Corporation
    Inventors: Richard G. Cliff, Srinivas T. Reddy, Kerry Veenstra, Andreas Papaliolios, Chiakang Sung, Richard Shaw Terrill, Rina Raman, Robert Richard Noel Bielby
  • Patent number: 6184705
    Abstract: Programmable logic array devices are programmed from programming devices in networks that facilitate programming any number of such logic devices with programs of any size or complexity. The source of programming data and control may be a microprocessor or one or more serial EPROMs, one EPROM being equipped with a clock circuit. Several parallel data streams may be used to speed up the programming operation. A clock circuit with a programmably variable speed may be provided to facilitate programming logic devices with different speed characteristics. The programming protocol may include an acknowledgment from the logic device(s) to the programming data source after each programming data transmission so that the source can automatically transmit programming data at the speed at which the logic device is able to accept that data.
    Type: Grant
    Filed: December 2, 1997
    Date of Patent: February 6, 2001
    Assignee: Altera Corporation
    Inventors: Richard G. Cliff, Srinivas T. Reddy, Andreas Papaliolios
  • Patent number: 6157210
    Abstract: A programmable logic device is provided that contains circuitry that may be used for observing logic signals from programmable logic circuits on the device for testing the operation of the device. Circuitry is also provided that may be used for preloading data into various circuits on the device. The logic signal observing circuitry may allow registered signals to be observed, may allow combinatorial signals to be observed, or may allow both registered and combinatorial signals to be observed.
    Type: Grant
    Filed: May 21, 1998
    Date of Patent: December 5, 2000
    Assignee: Altera Corporation
    Inventors: Ketan Zaveri, Christopher F. Lane, Srinivas T. Reddy, Andy L. Lee, Cameron R. McClintock, Bruce B. Pedersen
  • Patent number: 6154055
    Abstract: A programmable logic array integrated circuit device includes a plurality of regions of programmable logic disposed on the device in a two-dimensional array of intersecting rows and columns. Interconnection conductors are associated with each row and column. The interconnection conductors associated with each row include some that extend continuously along the entire length of the row and some that extend continuously along only the left or right half of the row. To increase the flexibility with which the logic regions can be connected to the row and column conductors, adjacent regions are paired and circuitry is provided for allowing the outputs of each pair to be swapped for driving the row and column conductors. Registers in logic regions can still be used for other purposes when not being used to register the main combinatorial outputs of the logic regions. Many other enhanced features are also provided.
    Type: Grant
    Filed: September 24, 1999
    Date of Patent: November 28, 2000
    Assignee: Altera Corporation
    Inventors: Richard G. Cliff, Srinivas T. Reddy, Rina Raman, L. Todd Cope, Joseph Huang, Bruce B. Pedersen