Abstract: Method and apparatus for auto-negotiation of a programmable logic device for any of a plurality of communication protocols is described. The programmable logic device is programmed for auto negotiation to establish a communication session. The programmable logic device has access to transceiver attributes. A portion of the transceiver attributes are selected in response to session information from the auto negotiation. The portion of the transceiver attributes selected are for configuring at least one transceiver for a communication protocol.

Abstract: During a reset condition or prior to system initialization of an FPGA-based system (100), a FPGA (102) can be pre-configured by loading a value from a memory cell (108) into at least one flip-flop (312) of the FPGA, which represents a configuration register for an FPGA memory controller (106). The FPGA memory controller can be configured using the value loaded in the flip-flop. The value loaded into the flip-flop from the memory cell can be a default value previously stored in the memory cell.

Abstract: A Transmit line driver with selectable pre-emphasis and driver signal magnitudes comprises a primary current driver for setting a primary current level and a pre-emphasis current driver that provides an additional amount of current that is superimposed with or added to the primary current level produced by the primary current driver. The pre-emphasis current has either negative or positive magnitude based upon a pre-emphasis signal logic state. A first current selection module defines a reference signal that is used to select the primary current driver output signal magnitude in a first current mirror, while a second current selection module is used to define a second reference signal that selects a pre-emphasis current driver signal magnitude in a second current mirror. Logic generates a binary signal to both the first and second current selection modules to select the current levels as well as the pre-emphasis signal.

Abstract: Described are glitchless clock control circuits capable of switching away from a failed clock. One embodiment supports three basic functions: clock select, clock enable, and clock ignore. The clock-select function provides a selected one of a plurality of clock signals on a clock-distribution node. The select signals used to switch between clock signals need to be synchronous with any of the clock signals. The clock-enable function allows the clock control circuit to synchronously block or pass a selected clock signal. Finally, the clock-ignore function allows the clock control circuit to ignore a selected clock if necessary, for example, to switch away from a failed clock.

Abstract: A verification agent can be used to verify hard and/or soft modules under test in an integrated circuit. The integrated circuit contains a processor and memory for storing code executable by the processor. The module under test performs predetermined operations. The verification agent interacts with the module under test, including sending signals to the module under test and generating results based on the interaction. The code causes the processor to receive the results and compare the results with expected values. The module under test may be deemed to operate properly if the actual results match the expected values.

Abstract: An Electrostatic Discharge (ESD) protection circuit activates an ESD conduction circuit in response to an ESD event. A deactivation circuit generates an exponentially increasing deactivation signal in response to the ESD event, such that once the deactivation signal has increased to a trigger point of a control circuit, the ESD conduction circuit is deactivated. An active resistance component within the deactivation circuit incorporates a biasing element to maintain a resistance value of the active resistance component substantially constant over all operating conditions.

Abstract: A programmable logic device (PLD) having heterogeneous programmable logic blocks. In one embodiment, the PLD includes programmable interconnect circuitry and programmable input-output circuitry coupled to the programmable interconnect circuitry. An array of programmable logic blocks is coupled to the interconnect circuitry. Each programmable logic block includes a plurality of programmable logic elements coupled to the interconnect circuitry. Each of the programmable logic elements is programmable to implement a common set of functions, and at least one but less than all of the programmable logic elements is programmable to implement a set of supplemental functions.

Abstract: An integrated circuit (IC) with programmable circuitry having programmable functions and programmable interconnections. The IC further includes: a first module having an output with a first fixed data width or first variable data width; a second module having an input with a second fixed data width or a second variable data width; and a data width converter receiving data from the output of the first module and sending the data to the input of the second module, the data width converter configured to convert data from the first fixed data width or first variable data width to the second fixed data width or the second variable data width.

Abstract: Method and apparatus for a dynamically reconfigurable system monitor (20) are described. A system monitor (20) has registers (206) accessible via a reconfiguration port (201). At least one of the registers may be dynamically reconfigured via the reconfiguration port (201) to select a channel to be monitored or to store an alarm value to be used in monitoring by the system monitor (20). Additionally, the system monitor (20) may be embedded in a columnar block architecture.

Abstract: Method and apparatus for data transfer validation is described. Configuration data is obtained. A signature for the configuration data is generated. The configuration data and the signature are stored in a first memory. The configuration data is transferred to a second memory for storage. The configuration data transferred is read to generate another signature, where the other signature is for the configuration data transferred. The configuration data read is compressed to provide the other signature. The signature is transferred for comparison with the other signature to validate whether the configuration data transferred was transferred without error. The method and apparatus may be used when transferring configuration data, including, but not limited to, transfer of configuration data from a memory to a programmable logic device.

Abstract: Described are regulated cascode amplifiers with improved low-voltage performance. The improved amplifier is similar to conventional regulated cascode amplifiers, including a cascode circuit and a feedback amplifier. The cascode circuit conventionally includes two output transistors, the first of which preferably remains in saturation to provide a relatively stable output resistance over a range of output voltages. A booster circuit in accordance with one embodiment maintains the first transistor of the cascode circuit in saturation over a broader range of output voltages, and consequently extends the low-end of the operating range of the cascode amplifier.

Abstract: It is sometimes desirable to encrypt a design for loading into a PLD so that an attacker may not learn and copy the design as it is being written into the PLD. It is desirable that decryption keys be stored within the PLD, and that they be loaded conveniently before a board including the PLD is sold. The invention allows the PLD to be placed into a printed circuit board and the board to be tested using a JTAG port of the PLD, and then allows the decryption keys to be loaded into a key memory using the JTAG port. Loading of the keys can be performed without also loading of a design into the PLD. Loading may be performed without the use of a device programmer.

Abstract: Method and apparatus for dynamic configuration of function block logic of an integrated circuit is described. The integrated circuit includes a reconfiguration port coupled to a controller. The controller is coupled to an array of memory cell. A portion of the array of memory cells is coupled for read/write communication with the controller, and another portion of the array of memory cells is not coupled for read/write communication with the controller. The portion of the array of memory cells is configurable at an operational frequency of the integrated circuit for dynamic reconfiguration of the function block logic of the integrated circuit.

Abstract: A non-volatile product term cell is provided having a first floating gate located over a first p-channel transistor and a first n-channel transistor, and a second floating gate located over a second p-channel transistor and a second n-channel transistor. A control gate is located over the first and second floating gates. A first tunnel oxide capacitor is coupled to the first floating gate and a second tunnel oxide capacitor is coupled to the second floating gate. A first transistor pair is coupled between the first p-channel transistor and the second n-channel transistor, and a second transistor pair is coupled between the second p-channel transistor and the first n-channel transistor. The first and second floating gates are programmed and/or erased. Complementary input signals are applied to the first and second transistor pairs. An output signal is provided in response to the programmed/erased states of the first and second floating gates.

Abstract: Methods and structures for efficiently implementing an accumulator-based load-store CPU architecture in a programmable logic device (PLD). The PLD includes programmable logic blocks, each logic block including function generators that can be optionally programmed to function as lookup tables or as RAM blocks. Each element of the CPU is implemented using these logic blocks, including an instruction register, an accumulator pointer, a register file, and an operation block. The register file is implemented using function generators configured as RAM blocks. This implementation eliminates the need for time-consuming accesses to an off-chip register file or to a dedicated RAM block.

Abstract: Method and apparatus for a bi-direction interface and communication link are described. More particularly, an input/output block is formed with a digitally controlled impedance output driver output coupled at an input/output node to an input terminal of a differential amplifier. Another terminal of the differential amplifier is used for inputting a reference voltage. As the digitally controlled impedance output buffer may be adjusted for impedance matching with transmission line impedance, no parallel terminating resistance is needed. Accordingly, two such input/output blocks may be coupled to form a bi-directional communication link with the advantage of an absence of parallel termination resistance at inputs to such input/output blocks.

Abstract: A configurable low voltage differential signal (LVDS) system is located on a chip, such as a programmable logic device. The configurable LVDS system includes a pair of I/O pads, an LVDS transmitter for driving a differential output signal onto the I/O pads, an LVDS receiver for receiving a differential input signal from the I/O pads, and a termination resistor coupled across the pair of I/O pads, wherein the termination resistance can be enabled for use with either the LVDS transmitter or the LVDS receiver. Control circuitry is provided to control the selective enabling and disabling of the LVDS transmitter, the LVDS receiver and the termination resistance. This control circuitry can be configured in response to configuration data values stored on the chip.

Abstract: An algorithm that includes delay elements is used for echo cancellation. The delays allow burst processing of consecutive samples of transmitting and receiving signals in a telephone communication system. As a result, there is tremendous reduction of memory bandwidth when compared to conventional sample-by-sample processing of signals. This algorithm can be advantageously implemented in FPGAs. Echo in over a thousand channels can be cancelled using a FPGA and an external memory device.

Abstract: A programmable capacitor in an integrated circuit (IC) comprises a conductive line located parallel to an interconnect. When a bias voltage is applied to the conductive line, a parasitic capacitance is created between the interconnect and the conductive line. By properly sizing and locating the conductive line, a desired capacitance can be coupled to the interconnect. A bias control circuit can apply or remove the bias voltage from the conductive line, thereby enabling the capacitance to be coupled or decoupled, respectively, from the interconnect. Because of its simple construction, multiple capacitive structures can be formed around a single interconnect to provide capacitive adjustment capability. By changing the number of conductive lines to which the bias voltage is applied, the total capacitance provided by the multiple capacitive structures can be varied. A feedback loop can be incorporated to provide adjustment during IC operation.

Abstract: Method and apparatus for an interface to a system monitor (1600) is described. A controller (102) accessible via a port interface thereof (110) is configured for read/write access to configuration memory cells (1500) and for read access to status registers (1602). The configuration memory cells (1500) are addressable via a first address space, and the status registers (1602) are addressable via a second address space different from the first address space. The port interface (110) is configured to receive a plurality of signals including a data address signal (124) and a data clock signal (121). The data address signal (124) has address information for accessing either the first address space or the second address space.