Patents Assigned to Lattice Semiconductor Corp.
  • Patent number: 6981381
    Abstract: Device driver circuits based on H-bridges can be implemented to provide linear control of the H-bridge, reduce power losses, and reduce certain component size/cost. The driver circuits can use two feedback loops to operate the H-bridge in different regions and to guarantee that current flows through an H-bridge load device, such as a thermoelectric cooler, in only one direction at a given time. The H-bridge driver circuits can remove the possibility of high currents bypassing the load device and thus going directly through the switches on either side of the H-bridge driver. The H-bridge driver circuits also ensure careful control of the current applied to the H-bridge load device. Such driver circuits are particularly useful for controlling the current applied to thermoelectric devices.
    Type: Grant
    Filed: December 16, 2003
    Date of Patent: January 3, 2006
    Assignee: Lattice Semiconductor Corp.
    Inventors: Ching Wang, Robert M. Bartel, Hans W. Klein
  • Patent number: 6977408
    Abstract: An EEPROM device exhibiting high saturation current and low signal propagation delay and a process for fabricating the device that includes the formation of refractory metal silicide regions in the source and the drain regions and the gate electrode of an MOS transistor within an EEPROM memory cell. A floating-gate protect layer is formed over the floating-gate electrode and a relatively thick cap oxide layer is formed to overlie the floating-gate protect layer and the source and drain regions and gate electrode of the MOS transistor. A doped oxide layer is formed to overlie the cap oxide layer. The cap oxide layer is formed to a thickness sufficient to create strain in the channel region of the MOS transistor, while not having a thickness that could cause poor data retention in the EEPROM memory cell.
    Type: Grant
    Filed: June 30, 2003
    Date of Patent: December 20, 2005
    Assignee: Lattice Semiconductor Corp.
    Inventors: Chih-Chuan Lin, Sunil D. Mehta
  • Patent number: 6861868
    Abstract: A programmable semiconductor device comprising a plurality of I/O circuits arranged into blocks includes a routing structure for each block, wherein each routing structure may programmably route signals between its block's I/O circuits and the I/O circuits within the remaining blocks. Each I/O circuit associates with a pin such that each block has a set of pins. A SERDES and a FIFO buffer associate with each block. Each block's SERDES couples between the block's I/O circuits and the block's set of pins. Each FIFO buffer couples between the SERDES and its block's I/O circuits.
    Type: Grant
    Filed: June 16, 2003
    Date of Patent: March 1, 2005
    Assignee: Lattice Semiconductor Corp.
    Inventors: Om P. Agrawal, Jinghui Zhu, Kuang Chi, ChienKuang Chen
  • Patent number: 6848095
    Abstract: A method of assigning logic functions to macrocells assures that a maximum number of macrocells are assigned two or more logic functions. A first logic function is assigned to a macrocell without restriction. Rules are then applied to the macrocell to determine whether a second logic function may be assigned to the macrocell, and, if so, whether any restrictions exist on what the second logic function may be.
    Type: Grant
    Filed: May 17, 2002
    Date of Patent: January 25, 2005
    Assignee: Lattice Semiconductor Corp.
    Inventor: Chong M. Lee
  • Patent number: 6844757
    Abstract: A circuit is disclosed for a programmable logic device (PLD) environment that converts unordered bits in a PLD domain to fixed-width vectors in a vector domain. The fixed-width vectors may be used within a vector processing block (VPB) that operates on data in vector format. The PLD includes multiple programmable logic blocks that are configurable by a user. The logic blocks operate on data at a bit level resulting in unordered bits of information in a PLD domain. However, a vector processing block operates on data on a vector level (e.g., 8 bits, 16 bits, 32 bits, 64 bits, etc.). Thus, an interface is coupled between the programmable logic blocks and the vector processing block that converts at least a portion of the unordered bits of information from the PLD domain to one or more fixed-width vectors for use in the vector processing block. The interface may also perform scaling and/or sign extension on the unordered bits, to further free up expensive resources in the PLD domain.
    Type: Grant
    Filed: June 28, 2002
    Date of Patent: January 18, 2005
    Assignee: Lattice Semiconductor Corp.
    Inventor: Conrad Dante
  • Patent number: 6832231
    Abstract: Method and system for generating a multiple width (e.g., 16-bit width) pseudo-random number (PRN). Each of first and second 8-bit width PRNs is generated, using first and second LFSR configurations that incorporate first and second characteristic polynomials, at least one of which is irreducible. The first and second 8-bit PRNs are generated on a rising edge and on a falling edge, respectively, of a clock signal. The first and second 8-bit PRNs are combined by concatenation or by interleaving to form a 16-bit, or other multiple width, PRN.
    Type: Grant
    Filed: September 28, 2001
    Date of Patent: December 14, 2004
    Assignee: Lattice Semiconductor Corp.
    Inventors: Xueping Jiang, Ming Qu, Ji Zhao
  • Patent number: 6825733
    Abstract: System and method for providing a low noise signal having a broad tuning range (1 GHz to 10 GHz, or larger), with associated jitter no more than about 10 percent of the selected period of a target output signal. In a first stage, a ring-based VCO phase locked loop system provides a broad tuning range with some associated noise, and a second stage in a first state is relatively transparent, with no substantial differential attenuation based on frequency. After phase lock is achieved, the second stage is switched to a second state with low associated noise and high differential attenuation based on input signal frequency.
    Type: Grant
    Filed: November 20, 2002
    Date of Patent: November 30, 2004
    Assignee: Lattice Semiconductor Corp.
    Inventors: Ming Qu, Ji Zhao
  • Patent number: 6822477
    Abstract: An integrated circuit includes standard cells interspersed with islands of spare gates. The spare gates are arranged in multiple groups of spare gates, with each group of spare gates within a corresponding designated spare gate area of a standard cell portion of the integrated circuit. At least a given one of the groups of spare gates is arranged between first and second rows of the standard cells and includes one or more rows of spare gates. The spare gate islands may be distributed throughout the standard cell portion of the integrated circuit in a substantially uniform manner, for example, in accordance with a predetermined geometric pattern. The spare gates may be converted to active gates in conjunction with the automated place and route process using only conductors in one or more metal layers of the integrated circuit.
    Type: Grant
    Filed: June 20, 2003
    Date of Patent: November 23, 2004
    Assignee: Lattice Semiconductor Corp.
    Inventors: Craig Bingert, Christopher D. Gorsuch, Oscar G. Mercado, Anthony K. Myers, John A. Schadt, Brian W. Yeager
  • Patent number: 6814296
    Abstract: Antenna errors are corrected in an integrated circuit design utilizing spare gates distributed throughout the integrated circuit. An integrated circuit in accordance with the invention includes standard cells interspersed with spare gates. For example, the circuit may include one or more rows of spare gates arranged between groups of rows of standard cells, or islands of spare gates arranged between groups of rows of standard cells. A signal line of the integrated circuit having a detected antenna error associated therewith is coupled via one or more conductors associated with at least one metal layer of the integrated circuit to a diode or other antenna error control circuitry formed using at least one of the spare gates. The standard cells and spare gates are preferably placed in accordance with a placement operation of an automated place and route process of a standard cell computer-aided design (CAD) tool.
    Type: Grant
    Filed: April 30, 2002
    Date of Patent: November 9, 2004
    Assignee: Lattice Semiconductor Corp.
    Inventors: Jay H. Angle, Christopher D. Gorsuch, Oscar G. Mercado, Anthony K. Myers, John A. Schadt, Brian W. Yeager
  • Patent number: 6812738
    Abstract: A PLD is disclosed that uses vector routing between components. A vector routing path is coupled between the components and includes a group of wires for routing a group of bits as one vector so that all bits in the vector are switched at once and as a group by a single set of control signals. Vector switch boxes are used to switch entire vectors of a predetermined bit width and a fixed-bit order. The vector routing may be between components in a vector domain, within vector-based components, or between components in a PLD domain and a vector domain. The vector routing path may allow for time-division multiplexing. For example, different components may use the same vector routing path during different time slices. The vector routing path may be dynamically segmented. Dynamic segmentation allows different portions of the same vector routing path to be used simultaneously by different components. A component may be coupled to multiple vector routing paths through a multiplexer.
    Type: Grant
    Filed: September 25, 2002
    Date of Patent: November 2, 2004
    Assignee: Lattice Semiconductor Corp.
    Inventors: Conrad Dante, David Lee Rutledge, David J. Wicker, Jr.
  • Patent number: 6806771
    Abstract: An output block for an in-system programmable analog integrated circuit. The output block features an output amplifier that accepts a differential current-mode input signal and provides a single-ended output voltage. The output amplifier is also selectably operable as a linear amplifier, an integrator or a comparator. The output block also includes a common-mode feedback circuit (CMFB), an analog trim circuit (OATRM), a CLAMP circuit, and an offset calibration circuit (CLDAC), all coupled to the differential input of the output amplifier. The CMFB exhibits bandwidth comparable to that of the output amplifier and a drive capability that enables the differential-input to single-ended output conversion. The CLAMP is connected to the differential input in the comparator mode in order to avoid slow recovery from an overdrive condition. The OATRM forces a difference current into the differential input that compensates for a (gain independent) offset voltage that results from various mismatches.
    Type: Grant
    Filed: May 31, 2002
    Date of Patent: October 19, 2004
    Assignee: Lattice Semiconductor Corp.
    Inventors: Paul Hildebrant, Jian Li, Hans W. Klein
  • Patent number: 6803787
    Abstract: A programmable logic device (PLD) is disclosed that includes a state machine integrated into a block memory. The state machine includes state machine logic and memory elements from the block memory. The state machine logic and memory elements together may be used as an instruction unit of a processor. In such a case, the instruction unit is coupled to a processor execution unit to form a high-performance, embedded processor within a PLD.
    Type: Grant
    Filed: September 25, 2002
    Date of Patent: October 12, 2004
    Assignee: Lattice Semiconductor Corp.
    Inventor: David J. Wicker, Jr.
  • Patent number: 6797568
    Abstract: High voltage (HV), single polysilicon gate NMOS and PMOS transistors in double polysilicon stacked gate flash technology and methods for making the same are described. Specifically, the methods provide for the formation of (and devices comprise) high voltage polysilicon 1 and polysilicon 2 transistors (NMOS and PMOS) in double polysilicon stacked gate flash technology. Different types of transistors (e.g., HV P1 NMOS, HV P1 PMOS, HV P2 NMOS, HV P2 PMOS, LV P1 NMOS, LV P1 PMOS, LV P2 NMOS, LV P2 PMOS) are formed along with a stacked-gate double-poly transistor, thereby providing versatility in flash technology device design. The polysilicon 1 transistors may be salicided without adding to the complexity of the double poly stacked gate fabrication process. In addition, the stacked gate device may include polysilicon 2 only transistors.
    Type: Grant
    Filed: November 21, 2002
    Date of Patent: September 28, 2004
    Assignee: Lattice Semiconductor Corp.
    Inventor: YongZhong Hu
  • Patent number: 6772230
    Abstract: An embedded system bus is woven between a plurality of embedded master elements and at least one slave element within the FPGA device, and provides an external processor interface allowing direct access to any of the plurality of embedded slave elements. Using the embedded system bus, any of a plurality of masters may be allowed to program an embedded element, e.g., embedded FPGA logic, whereas conventional FPGAs allowed only a single master (e.g., a processor) to program the embedded FPGA logic. The embedded system bus is a group of signals, typically data, address and control, that connects system elements together and provides a basic protocol for the flow of data. The embedded system bus allows for control, configuration and status determination of the FPGA device. The embedded system bus is preferably a dedicated function available at all times for arbitrated access to allow communication between the various embedded system components.
    Type: Grant
    Filed: May 25, 2001
    Date of Patent: August 3, 2004
    Assignee: Lattice Semiconductor Corp.
    Inventors: Zheng Chen, Richard G. Stuby, Jr.
  • Patent number: 6710641
    Abstract: A bandgap reference circuit that operates with a voltage supply that can be less than 1 volt and that has one stable, non-zero current operating point. The core has a current generator embedded within it and includes one operational amplifier that provides a self-regulated voltage for several transistors used in the circuit.
    Type: Grant
    Filed: December 2, 2002
    Date of Patent: March 23, 2004
    Assignee: Lattice Semiconductor Corp.
    Inventors: Quan Yu, Edwin Chan
  • Patent number: 6701340
    Abstract: A double differential comparator can be efficiently implemented utilizing a first comparator stage having a folded cascode with floating gate input terminals and clamped single-ended output, and a capacitively coupled input stage for transferring a weighted sum of input signals to the floating gates of the first comparator stage. Additionally, the double differential comparator can be integrated into fully differential programmable analog integrated circuits. Such fully differential programmable analog integrated circuits can also include a differential output digital-to-analog converter to be used with or without the double differential comparator.
    Type: Grant
    Filed: September 22, 2000
    Date of Patent: March 2, 2004
    Assignee: Lattice Semiconductor Corp.
    Inventors: James L. Gorecki, Bill G. Gazeley, Yaohua Yang
  • Patent number: 6693830
    Abstract: An EEPROM cell includes a sense transistor and a select transistor, each having a first active region (110, 114) formed in a substrate, and sharing a second active region (112). The EEPROM cell may also include a floating gate (125) having a first portion (FG2) forming a gate region for said sense transistor, and a second portion (FG1) overlying the second active region and forming a program junction with said second active region. The first portion of said floating gate has a concentration of an impurity greater than a concentration of said impurity in the second portion of the floating gate.
    Type: Grant
    Filed: October 22, 2001
    Date of Patent: February 17, 2004
    Assignee: Lattice Semiconductor Corp.
    Inventors: Yongzhong Hu, Jein-Chen Young
  • Patent number: 6680625
    Abstract: High speed CML logic gate systems for providing selected Boolean logic functions. Two halves of a substantially symmetric first system, having a relatively small number (14) of CMOS transistors, are used to generate any of the logic functions AND, NAND, OR and NOR. Two halves of a substantially symmetric second system having another small number (10) of transistors are used to generate any of the logic functions XOR, XNOR and NOT. In either system, the sum of currents passing through certain voltage-controlling gates is substantially constant.
    Type: Grant
    Filed: January 31, 2002
    Date of Patent: January 20, 2004
    Assignee: Lattice Semiconductor Corp.
    Inventors: Kochung Lee, Ming Qu, Xueping Jiang, Xiang Zhu
  • Patent number: 6660579
    Abstract: A method for forming a three transistor zero power memory cell including a p-channel sense transistor, an n-channel write transistor, and an n-channel sense transistor including: implanting a p-type impurity into a p-type substrate in which a n-channel high voltage transistor will be formed; implanting an n-type impurity into an n-type well in a p-type substrate in which a p-channel high voltage transistor will be formed; forming a mask to allow implants to occur to p-channel devices; performing a series of n-type dopant implants into the substrate where the p-channel transistors will be formed; growing a high voltage gate oxide; forming a mask to allow implants to occur to n-channel devices, said mask blocking implants to said n-channel sense transistor; and performing a series of p-type implants into the substrate where the n-channel devices will be formed. In addition, a memory cell which may include a first NMOS transistor having a source, drain and gate, and a first PMOS transistor is disclosed.
    Type: Grant
    Filed: April 24, 2002
    Date of Patent: December 9, 2003
    Assignee: Lattice Semiconductor Corp.
    Inventors: Chun Jiang, Sunil Mehta, Stewart Logie
  • Patent number: 6631487
    Abstract: A method of testing field programmable gate array (FPGA) resources and identifying faulty FPGA resources during normal on-line operation includes configuring an FPGA into a working area and an initial self-testing area. The working area maintains normal operation of the FPGA throughout testing and identifying of the resources. Within the initial and subsequent self-testing areas, the FPGA resources are initially tested for faults. Upon detection of a fault in the FPGA resources, the initial self-testing area resources are reconfigured or subdivided and further tested in order to identify the faulty resource. Dependent upon the further test results, the FPGA resources may be further subdivided and tested until the faulty resource is identified. Once the faulty resource is identified, the FPGA is reconfigured to replace unusable faulty resources or to avoid faulty modes of operation of partially faulty resources diagnosed during further testing.
    Type: Grant
    Filed: September 27, 2000
    Date of Patent: October 7, 2003
    Assignees: Lattice Semiconductor Corp., University of Ketucky Research Foundation
    Inventors: Miron Abramovici, Charles E. Stroud