Patents Assigned to Actel Corporation
  • Publication number: 20070103966
    Abstract: The present system comprises a radiation tolerant programmable logic device having logic modules and routing resources coupling together the logic modules. Configuration data lines providing configuration data control the programming of the logic modules and the routing resources. Error correction circuitry coupled to the configuration data lines analyzes and corrects any errors in the configuration data that may occur due to a single event upset (SEU).
    Type: Application
    Filed: December 28, 2006
    Publication date: May 10, 2007
    Applicant: ACTEL CORPORATION
    Inventor: William Plants
  • Publication number: 20070104009
    Abstract: A circuit for selectively interconnecting two nodes in an integrated circuit device includes a memory array having a plurality of wordlines and a plurality of bitlines. A refresh transistor has a source coupled to one of the plurality of bitlines, a control gate coupled to a dynamic random access memory wordline and a drain. A switching transistor has a gate coupled to the drain of the refresh transistor, a source coupled to a first one of the nodes and a drain coupled to a second one of the nodes. An address decoder for supplies periodic signals to the wordlines and the dynamic random access memory wordline.
    Type: Application
    Filed: January 3, 2007
    Publication date: May 10, 2007
    Applicant: ACTEL CORPORATION
    Inventors: John McCollum, Vidya Bellippady, Gregory Bakker
  • Patent number: 7212030
    Abstract: A multi-directional routing repeater has a plurality of buffers, each of the plurality of buffers has an input and an output. The output of each of the plurality of buffers is connected to a separate routing line for transmitting a signal in a separate direction of a first set of routing lines, and the input of each of the plurality of buffers is connected to one of a first set of programmable switches, one of a second set programmable switches, one of a third set of programmable switches, and one of a fourth set of programmable switches, and each one of the first set of programmable switches is connected to a separate one of the second set of programmable switches and a separate one of the second set of programmable switches, none of which are connected to an input of a same one of the plurality of buffers. Each one of the first set of programmable switches is connected to a separate routing line for transmitting a signal in a separate direction of a second set of routing lines.
    Type: Grant
    Filed: December 31, 2004
    Date of Patent: May 1, 2007
    Assignee: Actel Corporation
    Inventor: Volker Hecht
  • Patent number: 7213091
    Abstract: An SRAM bus architecture includes pass-through interconnect conductors. Each of the pass-through interconnect conductors is connected to routing channels of the general interconnect architecture of the FPGA through an element which includes a pass transistor connected in parallel with a tri-state buffer. The pass transistors and tri-state buffers are controlled by configuration SRAM bits. Some of the pass-through interconnect conductors are connected by programmable elements to the address, data and control signal lines of the SRAM blocks, while other pass through the SRAM blocks with out being further connected to the SRAM bussing architecture.
    Type: Grant
    Filed: April 24, 2006
    Date of Patent: May 1, 2007
    Assignee: Actel Corporation
    Inventor: William C. Plants
  • Publication number: 20070091683
    Abstract: A method for erasing a non-volatile memory cell interconnect switch in an FPGA comprised providing an FPGA having a core containing a plurality of non-volatile-memory-cell interconnect switches, each switch formed in a switch well region and coupled to a source/drain of an n-channel transistor formed in a grounded well region separate from the switch well region. A non-volatile memory cell interconnect switch is selected for erasing. The switch well region is disconnected from ground. A VCC potential is applied to the switch well region and to the drain of the n-channel transistor to which it is coupled and an erase potential is applied to the gate of the selected non-volatile memory cell interconnect switch.
    Type: Application
    Filed: December 6, 2006
    Publication date: April 26, 2007
    Applicant: ACTEL CORPORATION
    Inventors: Volker Hecht, John McCollum
  • Publication number: 20070089082
    Abstract: A freeway routing system for connecting input and output ports of interface groups of tiles in a field programmable gate array. The freeway system has a first set of routing conductors configured to transfer signals between the input ports of interface groups in a first tile of the field programmable gate array and the output ports of interface groups of other tiles in the field programmable gate array. The first set conductors include vertical conductors that form intersections with horizontal conductors and programmable interconnect elements located at the intersections of the vertical conductors and horizontal conductors in a diagonal orientation to connect each of the horizontal conductors to one of the vertical conductors.
    Type: Application
    Filed: November 8, 2006
    Publication date: April 19, 2007
    Applicant: ACTEL CORPORATION
    Inventors: Tong Liu, Jung-Cheun Lien, Sheng Feng, Eddy Huang, Chung-Yuan Sun, Naihui Liao, Weidong Xiong
  • Publication number: 20070075742
    Abstract: An apparatus includes an FPGA, which includes a first FPGA tile including a plurality of FGs, a first, second, and third set of routing conductors, and a plurality of IGs. The FGs are arranged in rows and columns with each FG being configured to receive tertiary and regular input signals, perform a logic operation, and generate regular output signals. The third set of routing conductors is coupled to the first set of output ports of the FGs and configured to receive signals, route signals within the FPGA tile, and provide input signals to the third set of input ports of the FGs. The IGs surround the FGs such that one IG is positioned at each end of each row and column. Each IG is coupled to the third set of routing conductors and configured to transfer signals from the third set of routing conductors to outside the first FPGA tile.
    Type: Application
    Filed: November 20, 2006
    Publication date: April 5, 2007
    Applicant: ACTEL CORPORATION
    Inventors: Sheng Feng, Jung-Cheun Lien, Eddy Huang, Chung-Yuan Sun, Tong Liu, Naihui Liao, Weidong Xiong
  • Patent number: 7199609
    Abstract: A method of forming a field programmable gate array architecture having a plurality of input/output pads comprising: providing a plurality of logic clusters; providing a plurality of input/output clusters; providing a plurality of input/output buffers; providing a plurality of dedicated input/output first-in/first-out memory blocks, the dedicated input/output first-in/first-out memory blocks having a first-in/first-out memory coupled to one of the plurality of input/output pads; providing an input/output block controller programmably coupled to the plurality of dedicated input/output first-in/first-out memory blocks, wherein the input/output block controller comprises a dedicated FIFO flag logic block and an input/output FIFO block controller cluster; and providing a routing interconnect architecture programmably coupling the logic clusters, the input/output buffers and the input/output clusters, wherein the dedicated input/output first-in/first-out memory blocks are programmably coupled between the input/out
    Type: Grant
    Filed: July 6, 2006
    Date of Patent: April 3, 2007
    Assignee: Actel Corporation
    Inventors: William C. Plants, Arunangshu Kundu
  • Patent number: 7193885
    Abstract: In an integrated circuit, a radiation tolerant static random access memory device comprising a first inverter having an input and an output, a second inverter having an input and an output. A first resistor is coupled between the output of the first inverter and the input of the second inverter. A second resistor is coupled between the output of the second inverter and the input of the first inverter. A first write transistor is coupled to the output of the first inverter and has a gate coupled to a source of a first set of write-control signals and a second write transistor is coupled to the output of the second inverter and has a gate coupled to said source of a second set of write-control signals. Finally, a pass transistor has a gate coupled to the output of on of the first and second inverters.
    Type: Grant
    Filed: January 5, 2004
    Date of Patent: March 20, 2007
    Assignee: Actel Corporation
    Inventor: John McCollum
  • Patent number: 7187610
    Abstract: A method for providing a circuit for selectively interconnecting N pairs of nodes in an integrated circuit device comprising: providing a memory array having a plurality of wordlines and a plurality of bitlines; providing a plurality of dynamic random access memory wordlines; providing a separate switch for each pair of nodes in the integrated circuit, each switch associated with a unique combination of one of the plurality of bitlines and one of the plurality of dynamic random access memory wordlines, each switch including a refresh transistor and a switching transistor; and providing an address decoder having at least N distinct states for supplying signals to the plurality of wordlines and the plurality of dynamic random access memory wordlines.
    Type: Grant
    Filed: July 10, 2006
    Date of Patent: March 6, 2007
    Assignee: Actel Corporation
    Inventors: John McCollum, Vidya Bellippady, Gregory Bakker
  • Publication number: 20070046325
    Abstract: An integrated circuit includes a plurality of inputs, a plurality of output pads, a programmable logic block, an analog circuit block, an analog-to-digital converter programmably coupleable to individual analog circuits in the analog circuit block, and an interconnect architecture programmably coupling selected ones of the plurality of inputs, the plurality of outputs, the programmable logic block, the analog circuit block, and the analog-to-digital converter. At least one of the inputs may be programmably configured as one of a digital input programmably coupleable to elements in the programmable logic block or as an analog input to an analog circuit in the analog circuit block.
    Type: Application
    Filed: October 23, 2006
    Publication date: March 1, 2007
    Applicant: ACTEL CORPORATION
    Inventors: Rabindranath Balasubramanian, Limin Zhu, Theodore Speers, Gregory Bakker
  • Publication number: 20070047330
    Abstract: A non-volatile-memory-transistor based lookup table for an FPGA includes a n:1 multiplexer. A non-volatile memory transistor is coupled to each of the n inputs of the multiplexer. The multiplexer has x address inputs wherein 2x=n as is known in the art. The output of the multiplexer is coupled to VCC through a pullup transistor. The gate of the pullup transistor is coupled to the output of an address transition detector circuit that has inputs coupled to the address inputs of the multiplexer. A sense amplifier is coupled to the output of the multiplexer.
    Type: Application
    Filed: October 23, 2006
    Publication date: March 1, 2007
    Applicant: ACTEL CORPORATION
    Inventors: John McCollum, Gregory Bakker, Jonathan Greene
  • Patent number: 7173448
    Abstract: The present system comprises a radiation tolerant programmable logic device having logic modules and routing resources coupling together the logic modules. Configuration data lines providing configuration data control the programming of the logic modules and the routing resources. Error correction circuitry coupled to the configuration data lines analyzes and corrects any errors in the configuration data that may occur due to a single event upset (SEU).
    Type: Grant
    Filed: March 2, 2006
    Date of Patent: February 6, 2007
    Assignee: Actel Corporation
    Inventor: William C. Plants
  • Patent number: 7170315
    Abstract: A programmable system-on-a-chip integrated circuit device comprises a programmable logic block, a non-volatile memory block, an analog sub-system, an analog input/output circuit block, and a digital input/output circuit block. A programmable interconnect architecture includes programmable elements and interconnect conductors. Ones of the programmable elements are coupled to the programmable logic block, the non-volatile memory block, the analog sub-system, the analog input/output circuit block, the digital input/output circuit block, and to the interconnect conductors, such that inputs and outputs of the programmable logic block, the non-volatile memory block, the analog sub-system, the analog input/output circuit block, and the digital input/output circuit block can be programmably coupled to one another.
    Type: Grant
    Filed: May 10, 2004
    Date of Patent: January 30, 2007
    Assignee: Actel Corporation
    Inventors: Greg Bakker, Khaled El-Ayat, Theodore Speers, Limin Zhu, Brian Schubert, Rabindranath Balasubramanian, Kurt Kolkind, Thomas Barraza, Venkatesh Narayanan, John McCollum, William C. Plants
  • Patent number: 7171575
    Abstract: A DLL provides a deskew mode for aligning a reference clock that passes through a clock distribution tree to a feedback by adding additional delay to the feedback clock to align the feedback clock with reference clock at one cycle later. A 0 ns clock-to-out mode is provided by adding additional delay to account for an input buffer into a feedback path. The feedback clock can be doubled by a clock doubler with 50% duty cycle adjustment disposed in the feedback path. Flexible timing is aligning the reference clock to the feedback clock is obtained with additional delay elements disposed in the feedback and reference clock paths.
    Type: Grant
    Filed: July 25, 2005
    Date of Patent: January 30, 2007
    Assignee: Actel Corporation
    Inventors: William C. Plants, Nikhil Mazumder, Arunangshu Kundu, James Joseph, Wayne W. Wong
  • Patent number: 7161841
    Abstract: A method for erasing a non-volatile memory cell interconnect switch in an FPGA comprises providing an FPGA having a core containing a plurality of non-volatile-memory-cell interconnect switches, each switch formed in a switch well region and coupled to a source/drain of an n-channel transistor formed in a grounded well region separate from the switch well region. A non-volatile memory cell interconnect switch is selected for erasing. The switch well region is disconnected from ground. A VCC potential is applied to the switch well region and to the drain of the n-channel transistor to which it is coupled and an erase potential is applied to the gate of the selected non-volatile memory cell interconnect switch.
    Type: Grant
    Filed: June 29, 2005
    Date of Patent: January 9, 2007
    Assignee: Actel Corporation
    Inventors: Volker Hecht, John McCollum
  • Patent number: 7157938
    Abstract: An apparatus includes an FPGA, which includes a first FPGA tile including a plurality of FGs, a first, second, and third set of routing conductors, and a plurality of IGs. The FGs are arranged in rows and columns with each FG being configured to receive tertiary and regular input signals, perform a logic operation, and generate regular output signals. The third set of routing conductors is coupled to the first set of output ports of the FGs and configured to receive signals, route signals within the FPGA tile, and provide input signals to the third set of input ports of the FGs. The IGs surround the FGs such that one IG is positioned at each end of each row and column. Each IG is coupled to the third set of routing conductors and configured to transfer signals from the third set of routing conductors to outside the first FPGA tile.
    Type: Grant
    Filed: January 18, 2006
    Date of Patent: January 2, 2007
    Assignee: Actel Corporation
    Inventors: Sheng Feng, Jung-Cheun Lien, Eddy C. Huang, Chung-Yuan Sun, Tong Liu, Naihui Liao, Weidong Xiong
  • Publication number: 20060284666
    Abstract: An integrated temperature-compensated RC oscillator circuit includes an inverter having an input and an output. An RC network is coupled between the inverter and a pair of comparators. A first comparator has an inverting input coupled to a first reference voltage, a non-inverting input coupled to the RC network, and an output. A second comparator has an inverting input coupled to the RC network, a non-inverting input coupled to a second reference voltage, and an output. A set-reset flip-flop has a set input coupled to the output of the first comparator, a reset input coupled to the output of the second comparator, and an output coupled to the input of the inverter. Differential amplifiers in the comparators each have a diode-connected p-channel MOS transistor controlling a mirrored p-channel MOS transistor whose channel width is less than that of the diode-connected p-channel current mirror transistor.
    Type: Application
    Filed: August 25, 2006
    Publication date: December 21, 2006
    Applicant: ACTEL CORPORATION, a California Corporation
    Inventor: Gregory Bakker
  • Publication number: 20060284324
    Abstract: A power-up and power-down circuit for an integrated circuit includes a voltage regulator set for a first voltage. A first I/O pad is coupled internally to an input to the voltage regulator and to first internal circuits. The second voltage is externally coupled to the first I/O pad. A second I/O pad is coupled internally to an output of the voltage regulator configured to drive the base of an external transistor. A third I/O pad of the integrated circuit is coupled internally to a reference-voltage input of the voltage regulator. A fourth I/O pad is coupled to a feedback input of the voltage regulator. A fifth I/O pad of the integrated circuit is coupled internally to logic circuitry that controls power-up and power down of the integrated circuit from internal signals including internal signals from a real-time clock circuit disposed on the integrated circuit.
    Type: Application
    Filed: August 25, 2006
    Publication date: December 21, 2006
    Applicant: ACTEL CORPORATION
    Inventor: Gregory Bakker
  • Publication number: 20060279327
    Abstract: A non-volatile memory configuration scheme is disclosed for volatile-memory-based programmable circuits in a programmable integrated circuit that includes an FPGA fabric, a plurality of first configurable circuit elements external to the FPGA fabric, and a plurality of second configurable circuit elements external to the FPGA fabric. A plurality of distributed configuration non-volatile memory cells is disposed in the FPGA, each one of the distributed configuration non-volatile memory cells coupled to a different one of the plurality of first configurable circuit elements. A non-volatile memory array stores configuration information for the second configurable circuit elements. A plurality of register cells is disposed with the second configurable circuit elements and is coupleable to the non-volatile memory array, each one of the register cells coupled to a different one of the plurality of second configurable circuit elements.
    Type: Application
    Filed: August 21, 2006
    Publication date: December 14, 2006
    Applicant: ACTEL CORPORATION
    Inventor: Theodore Speers