Abstract: A method and apparatus for the utilization of on-chip, programmable resources to implement a signal distortion characterization circuit. Programmable logic resources, such as programmable delay lines and phase shifting circuits, are utilized to obtain estimates of, for example, capacitive coupling of signal energy between various signal and clock routes within a programmable logic device (PLD). Progressively delayed/advanced samples are taken of a test signal transmitted through a victim net to form baseline test data. Samples of the test signal are then repeated in the presence of test signals transmitted through aggressor net(s) and compared to the baseline results to measure crosstalk distortion caused by capacitively coupled energy from the aggressor nets onto the victim net.

Abstract: In an integrated circuit including an array of substantially similar tiles, a tile includes a logic block and at least one column of routing multiplexers driving interconnect lines that can be used to programmably interconnect the logic blocks. An output terminal of the logic block drives a vertically adjacent subset of the routing multiplexers in the column. Optionally, the tile also includes a second column of routing multiplexers. The logic block output terminal also drives a vertically adjacent subset of the routing multiplexers in the second column, and in some embodiments the two subsets are physically located in horizontal alignment with one another within the tile. The tile can also include a column of input multiplexers for the logic block. The logic block output terminal also drives a vertically adjacent subset of the input multiplexers, and the subsets of routing multiplexers and input multiplexers can be horizontally aligned within the tile.

Abstract: A semiconductor component having test pads and a method and apparatus for testing the same is described. In an example, an un-bumped substrate is obtained having a pattern of bond pads configured to support bumped contacts and a plurality of test pads. Each of the plurality of test pads is in electrical communication with a respective one of the bond pads. The substrate is tested using the plurality of test pads. In another example, a substrate is fabricated having a pattern of bond pads configured to support bumped contacts and a plurality of test pads. Each of the plurality of test pads is in electrical communication with a respective one of the bond pads. The substrate is tested using the plurality of test pads. An insulating layer is formed over the plurality of test pads.

Abstract: The present invention allows a designer to easily re-target the design optimized for the device of one integrated circuit vendor to the device of another vendor. The designer can start with a set of post-routed boolean equations optimized for a certain target integrated circuit. The present invention allows the automatic generation of a synthesizable, editable, and simulatable HDL description. The designer may edit the HDL code. Another target may be selected. Design optimization and placement and routing can be performed for the new target.

Abstract: Method and apparatus for generating a test program for an integrated circuit having an embedded processor. One embodiment has a system which includes an embedded microprocessor; a plurality of assembly language instructions stored in a memory, where the assembly language instructions substantially exercise a critical path or a path closest to the critical path in the embedded microprocessor; and programmable test circuitry having a programmable clock circuit for providing a multiplied clock signal to the embedded microprocessor in order to execute the assembly language instructions.

Abstract: A programmable logic block provides N-bit and M-bit (e.g., (N/2)-bit) lookahead functionality for carry chains traversing the logic block, N and M being integers greater than one. An exemplary programmable logic block includes four carry multiplexers that together form a 4-bit lookahead carry chain. The 4-bit lookahead carry chain also provides a 2-bit lookahead output after the second carry multiplexer. Alternatively, the last two bits of the 4-bit lookahead carry chain can be used as a 2-bit lookahead carry chain. In one embodiment, the programmable logic block also includes four function generators associated with the four carry multiplexers. Each function generator drives a select terminal of the associated carry multiplexer. The 4-bit and 2-bit carry chains can be programmably coupled to an interconnect structure of the PLD at the carry out output terminals. In some embodiments, an initialization value can also be provided to the 4-bit and 2-bit carry chains.

Abstract: An FPGA having a programmable frequency output is provided that achieves a (theoretical) M-times reduction in output jitter from a conventional direct digital synthesis (DDS) circuit, by running M accumulator circuits in parallel and combining the outputs in a time-staggered way. I Initially the frequency number N added into the accumulators is varied slightly for each accumulator by multiplying by a number, such as X/16 where X varies from 1 to 16 for each of 16 accumulator circuits. The accumulator circuits are further reconfigured so that the output of a register from a first accumulator provides feedback to the adder input in all of the accumulator circuits. The number of overflowing accumulator registers in a clock cycle will then indicate granularity spatially. To translate spatial granularity to time, a programmable delay circuit is connected to the output of each accumulator register.

Abstract: A method and apparatus are provided for updating or changing configuration data stored in the PROM of a target system, the data being used to configure one or more reprogrammable logic devices such as FPGAs. In one embodiment the apparatus comprises a modem used to communicate remotely with a host system, a shadow PROM for receiving new configuration data intended for use in a target system, an interface for relaying configuration data from the shadow PROM to the target, and means for controlling the components of the update system.

Abstract: A programmable logic device (PLD) includes a plurality of configurable resources, a programmable interconnect having a plurality of signal lines for providing a number of dedicated signal paths between any of the configurable resources, and a subway routing system having a shared subway bus coupled to the signal lines of the programmable interconnect at a plurality of connection points by a plurality of corresponding subway ports. The subway routing system, which provides alternate routing resources for the programmable interconnect, may be used to route different signals between different configurable resources at different times.

Abstract: A method of specifying clock domains in electronic circuit designs in a system level design tool is disclosed. The method generally comprises steps of providing a design having a plurality of functional blocks; incorporating a clock tag block within the design; and setting a clock domain provided by the clock tag block for a functional block of the plurality of functional blocks. A design tool enabling the association of clock domains with functional blocks in a system is also disclosed. The design tool generally comprises a plurality of functional blocks; a clock tag block having a predetermined clock rate; and a user interface enabling the selection of the functional blocks and the clock tag block in a design. The clock tag block provides a clock rate for at least one functional block of the plurality of functional blocks.

Abstract: A programmable layered sub-system interface includes an extension sub-layer module, a physical coding sub-layer module, a physical media attachment module, an input module, an output module, a 1st switch module and a 2nd switch module. The 1st switch module is coupled between the physical media attachment module and the physical coding sub-layer module. The 2nd switch module is operably coupled between the physical coding sub-layer module and the extension sub-layer module. The input and output modules are operably coupled to the 1st and 2nd switch modules. The 1st switch module provides various combinations of coupling between the physical media attachment module, the physical coding sub-layer module, the input module and the output module. The 2nd switch module provides combinations of coupling between the extension sub-layer module, the physical coding sub-layer module, the input module and the output module.

Abstract: An example embodiment is directed to shifting the common mode voltage of an analog oscillation stage toward a center line between the upper and lower power-supply rails of a first digital circuit. The first digital circuit has a digital input port adapted to respond to signal transitions defined between the supply rails, and the analog oscillation stage generates an oscillating analog signal that has a common-mode voltage that is not centered between the upper and lower power-supply rails. The oscillating analog signal, which drives the digital input port, changes alternately with the phases of the oscillating analog signal. To shift the common mode voltage of an analog oscillation stage toward the center line between the rails, a feedback circuit generates a contending digital signal that drives the digital input port with alternating states as defined by opposite phases.

Abstract: A programmable logic device (PLD) includes a central processing unit (CPU) and a programmable interface coupled to the CPU, wherein the programmable interface includes a core designated by a user. The programmable interface core allows devices, both on and off-chip, to communicate with the CPU. In one embodiment, the programmable interface core includes a crosspoint switch for coupling a plurality of devices and the CPU. Re-programmability of the PLD provides significant flexibility in providing features that can be parameterized based on the user's needs and/or associated design. Specifically, these parameterized features can be implemented in programmable resources on the PLD, thereby allowing these features to be modified at any time. Moreover, only those resources actually needed for the programmable interface core need be implemented, thereby allowing the user to optimize use of the remainder of the PLD.

Abstract: A programmable differential signaling system includes a programmable bias generator and a plurality of input/output modules. The programmable bias generator is operably coupled to generate a first global bias signal and a second global signal based on desired signal properties of one of a plurality of differential signaling conventions. The a plurality of input/output modules is operably coupled to convert between differential signaling and single ended signaling, wherein actual signal properties of the differential signaling are regulated based on the first and second global bias signals to substantially equal the desired signal properties.

Abstract: An integrated circuit (IC) device includes a first voltage supply for powering first circuitry within the device, a second voltage supply for powering second circuitry within the device, a suspend circuit having an output to generate a power-down signal, and a voltage regulator circuit coupled to a power node. The voltage regulator circuit includes a first transistor coupled between the first voltage supply and the power node and having a gate responsive to a regulation signal, a second transistor coupled between the second voltage supply and the power node and having a gate responsive to the power-down signal, and a well bias circuit having an input coupled to receive the power-down signal, a first output coupled to a well region of the first transistor, and a second output coupled to a well region of the second transistor.

Abstract: A method and apparatus to provide triple modular redundancy (TMR) in one mode of operation, while providing multiple context selection during a second mode of operation. Intelligent voting circuitry facilitates both modes of operation, while further enhancing the robustness of the design when used in a TMR mode of operation. Various addressing schemes are provided, which allow dual use of the configuration data lines as selection signals using one addressing scheme, while allowing for dual use of the configuration address lines as selection signals using the second addressing scheme.

Abstract: A method and apparatus for performing a recursion process on a data block for error correction. The disclosure describes concurrently operating pipelined sub-processes that decode the data block with error correction. The pipelined sub-processes are implemented as sub-circuits of an integrated circuit. The output data from each sub-process is stored for input by a subsequent sub-process of the pipelined sub-processes.

Abstract: A programmable lookup table optionally provides two input signals and two output signals to an interconnect structure of a programmable integrated circuit when programmed to function as a random access memory (RAM). An integrated circuit includes an interconnect structure and a N-input lookup table (LUT) having input and output terminals coupled to the interconnect structure. The LUT can be configured to function as a single-bit wide RAM (e.g., a (2**N)×1 RAM) having N input address signals coupled to the interconnect structure and one output signal coupled to the interconnect structure, or as a multi-bit wide RAM (e.g., a (2**(N?1))×2 RAM) having fewer than N (e.g., N?1) input address signals coupled to the interconnect structure and at least two output signals coupled to the interconnect structure. Optionally, the LUT can also be configured as shift register logic, e.g., a 2**(N?1)-bit shift register or two 2**(N?2)-bit shift registers.

Abstract: Methods of testing a digital frequency synthesizer (DFS) having a programmable multiplier M and divider D. The full set of tests (wherein every value of M and D is tested) is reduced to a smaller set of tests in which each M/D ratio is tested to a specified resolution. A resolution and minimum and maximum values for M, D, and M/D are specified. An array is allocated, each M/D ratio having a corresponding location in the array, up to the specified resolution. For each MD pair meeting the specified criteria, an M/D ratio is calculated and idealized to the specified resolution, and the MD pair is stored in the corresponding array location. The result is an array of MD pairs that includes zero or one MD pair for each M/D ratio. Thus, by testing each MD pair within the array, all permissible permutations of the input clock frequency are tested.

Abstract: A crossbar switch is implemented in a reconfigurable circuit, such as a FPGA, instantiated with a number of modules, the crossbar switch providing communication links between the modules. The modules and crossbar switch can be easily updated in a partial reconfiguration process changing only portions of modules and the crossbar switch while other portions remain active. The crossbar switch uses individual wiring to independently connect module outputs and inputs so that asynchronous communications can be used. The crossbar switch can be implemented in different embodiments including a Clos crossbar switch, and a crossbar switch connecting each module output only to a corresponding module input, allowing for a reduction in the amount of FPGA resources required to create the crossbar switches.