Abstract: Method and circuits to create reduced field programmable gate arrays (RFPGA) from the configuration data of field programmable gate arrays (FPGA) are disclosed. The configurable elements of the FPGA are replaced with standard cell circuits that reproduce the functionality of the configured FPGA. Specifically, reduced logic blocks are derived from the configuration data of configurable logic blocks. Similarly, reduced input/output blocks and reduced matrices are derived from the configuration data for input/output blocks and programmable switch matrices of the FPGA, respectively. A database can be expanded as new reduced logic block models are created for configurable logic block models that were not in the database. Similarly, a database can be used for the input/output blocks and programmable switch matrices of an FPGA.

Abstract: A VCO (110) can be configured to convert an analog input signal (105) to a digital output signal (125). In accordance with the inventive arrangements, the VCO can convert the analog input signal to at least one intermediate signal (130) having a frequency dependent on the analog input signal. A frequency detector (115) can be configured to determine a frequency of at least one intermediate signal. Subsequently, a mapping circuit (120) can be configured to map the determined frequency of the at least one intermediate signal to an output value representing the digital output signal (125).

Abstract: A computer implemented apparatus and method that automates the entry, modification, analysis, and generation of test benches from electrical circuits, both of which are specified as hardware description language (HDL) files. The computer implemented-method and apparatus also provides a unique mechanism that blends entry and display of timing requirements that must be met by the electric circuit.

Abstract: A hot swap protection circuit (40) for an integrated circuit being plugged into a powered-up system includes a first circuit (10) for detecting a hot swap condition, a second circuit (20) coupled to the first circuit for preventing a pn junction diode (52) in a pull-up transistor (32) from going into a forward bias condition, and a third circuit (30) coupled to the first and second circuits for preventing the pull-up transistor from turning on during the hot swap condition.

Abstract: A lookup table (LUT) for a field programmable gate array (FPGA) is designed to operate reliably at low voltage levels. The low-voltage LUT uses CMOS pass gates instead of unpaired N-channel transistors to select one memory cell output as the LUT output signal. Therefore, no voltage drop occurs across the pass gates. While this modification significantly increases the overall gate count of the LUT, this disadvantage can be mitigated by removing the half-latches required in current designs, and by removing initialization circuitry made unnecessary by the modification. Some embodiments include a decoder that decreases the number of pass gates between the memory cells and the output terminal, at the cost of an increased delay on the input paths that traverse the decoder.

Abstract: Simple, glitch-free phase detector circuits provide add and subtract output signals indicating the phase relationship between two input clock signals. Some embodiments also provide a lock output signal having a lock window, and in some of these embodiments, the size of the lock window is programmable. An optionally delayed version of the feedback clock signal is stored a first time when the input clock signal goes high, then stored a second time after a predetermined delay. In some embodiments, the predetermined delay is programmable. When both stored values are low, the subtract output signal is active. When the first stored value is high, the add output signal is active, regardless of the state of the second stored value. When the first stored value is low and the second stored value is high, the two clocks are synchronized and the phase detector indicates a lock condition.

Abstract: A method for customization of the software of an FPGA-based SoC includes the steps of selecting (380) a system component used for customizing the FPGA-based SoC, configuring (382) the selected system component with parameters for use with the FPGA-based SoC and propagating (384) the parameters used to configure the selected system component to peer system components. The method further includes the step of configuring (388) the peer system components using the propagated parameters during customization of the FPGA-based SoC and creating (401) a software interface to the selected system components and to the peer system components.

Abstract: Novel structures for implementing wide multiplexers from user designs in FPGA CLBs. Input multiplexers providing the function generator data input signals are modified to function not just based on values stored in configuration memory cells, but also under the control of user signals. Thus, the input multiplexers of the invention are much more flexible than traditional input multiplexers. In one embodiment, the improved data input multiplexer is provided on two of four data input terminals of the function generator, enabling the implementation of an 8-to-1 multiplexer using only a single function generator. Another embodiment applies the concept of mixed memory cell and user control of a multiplexer to the general interconnect structure of an FPGA.

Abstract: A method for ensuring data coherency in buffered direct memory access (DMA) data transfers. The DMA controller realizes the last piece of data is being transferred to the write buffer. The DMA controller then sends a “Last Write Data” signal to the external memory access arbitration unit. The external memory access arbitration unit then allows completion of all pending memory operations. If a memory request occurs, a wait line is asserted such that memory operations (i.e., reading from, or writing to, the memory) are prevented for all sources other than the DMA channel associated with the “Last Write Data” signal. The external memory access arbitration unit also grants priority to the DMA channel associated with the “Last Write Data” signal. This effectively flushes the write buffer and completes the buffered DMA data transfer. The external memory access arbitration unit then deasserts any asserted wait lines and memory operations are no longer prevented.

Abstract: Structures and methods of including processor capabilities in an existing PLD architecture with minimal disruption to the existing general interconnect structure. In a PLD including a column of block RAM (BRAM) blocks, the BRAM blocks are modified to create specialized logic blocks including a RAM, a processor, and a dedicated interface coupled between the RAM, the processor, and the general interconnect structure of the PLD. The additional area is obtained by increasing the width of the column of BRAM blocks. Because the interconnect structure remains virtually unchanged, the interconnections between the specialized logic blocks and the adjacent tiles are already in place, and the modifications do not affect the PLD routing software. In some embodiments, the processor can be optionally disabled, becoming transparent to the user. Other embodiments provide methods of modifying a PLD to include the structures and provide the capabilities described above.

Abstract: System and method for debugging a run-time reconfigurable processing arrangement. The processing arrangement includes a host process that hosts a run-time reconfiguration application program and a programmable logic device (PLD). The run-time reconfiguration program specifies a circuit design with references to core generators in a library, generates configuration data that implements the circuit design on the PLD, and configures the PLD with the configuration data. One of the core generators generates a breakpoint circuit that steps the PLD for a selected number of clock cycles. When the PLD is activated, the breakpoint circuit steps the PLD, and state information of one or more selected elements of the PLD is analyzed after stepping the PLD. Depending on the analysis, the breakpoint core generator is re-parameterized and the PLD reconfigured with a new breakpoint circuit to continue debugging.

Abstract: Circuit arrangements and methods for real-time image resizing and image rotation. Line buffers are used for storage of lines of pixel values for both resizing and rotation. A first one of the line buffers receives input pixel values, and the line buffers are coupled in a chain such that line buffer i receives pixel values from line buffer i−1. The lines of pixel values are moved from line buffer i to line buffer i+1 as the pixel values are processed for resizing or rotation.

Abstract: Described are methods and circuits for aligning data and clock signals. Methods in accordance with some embodiments separate incoming data into three differently timed data signals: an early signal, an intermediate signal, and a late signal. The timing of the three data signals can be collectively moved with respect to the clock signal. In addition, the temporal spacing between the three signals can be adjusted so that the early and late signals define a window encompassing the intermediate signal. The three signals are aligned with respect to the clock edge to center the intermediate data signal on the clock edge. The early and late signals can be monitored to identify changes in the relative timing of the clock and data signals. Some embodiments automatically alter the timing of the data and/or clock signals to keep the intermediate data signal centered on the clock edge.

Abstract: Interconnecting logic provides connectivity of an embedded fixed logic circuit, or circuits, with programmable logic fabric of a programmable gate array such that the fixed logic circuit functions as an extension of the programmable logic fabric. The interconnecting logic includes interconnecting tiles and may further include interfacing logic. The interconnecting tiles provide selective connectivity between inputs and/or outputs of the fixed logic circuit and the interconnects of the programmable logic fabric. The interfacing logic, when included, provides logic circuitry that conditions data transfers between the fixed logic circuit and the programmable logic fabric.

Abstract: A multiplexer circuit for programmable logic devices (PLDs) has reduced susceptibility to single event upsets. The pass gate multiplexer circuit has 2N pass gates and N memory cells controlling the pass gates. Each path between an input terminal and the output node includes two pass gates controlled by different memory cells. Therefore, a single event upset that inadvertently enables a pass gate can only short two input terminals when the other pass gate in the affected input path is also enabled by its associated memory cell. Therefore, the multiplexer circuit with two pass gates in each input path reduces the susceptibility to single event upsets by a factor of (N−4)/N.

Abstract: The present invention provides a new method to handle a signal that crosses one or more areas in modular design of programmable logic devices. Even when the signal have an attribute disallowing the use of programmable interconnect points on an associated wire, the programmable interconnect points may still be used if the wire has no input programmable interconnect points outside of the attribute's associated area. This approach makes use of the programmable interconnect point directionalities and allows for more programmable interconnect points to be used while guaranteeing that the detailed routing solution is conflict free and absent of signal shorts.

Abstract: Method for multithread processing of a packet is described. A packet recognition thread is initiated responsive to receiving the packet to a port triggering a media access control (“MAC”) recognition thread. A network protocol recognition thread is activated responsive to the MAC recognition thread for an initiating an address lookup thread and a MAC write thread. The MAC recognition thread, the network protocol thread, the address lookup thread and the MAC write thread all may complete their respective executions prior to completion of the packet recognition thread, thereby reducing latency in packet handling.

Abstract: Method and apparatus for simulating operations of a circuit design that includes high-level components and HDL components. The high-level components of the design are simulated in a high-level modeling system (HLMS), and the HDL components of the design are simulated with an HDL simulator. Data values are converted from a data type of the HLMS to a logic vector compatible with the HDL simulator for each data value to be input to the HDL simulator, and a logic vector is converted from the HDL simulator to a data value of a data type compatible with the HLMS for each logic vector output from the HDL simulator. Events are scheduled for input to the HDL simulator as a function of the time of HLMS events and a maximum response time of the HDL components.

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: The circuitry of a programmable logic device (for example, an FPGA) includes a configurable logic portion and a configuration memory. The configuration memory stores configuration data that configures the configurable logic portion to realize a user-defined circuit. The configurable logic portion is disposed on a first die whereas the configuration memory is disposed on a second die. The second die is bonded to the first die in stacked relation. Each bit of configuration data passes from the second die to the first die through a pair of micropads. One micropad of the pair is disposed on the first die and the other micropad of the pair is disposed on the second die. When the first die and second die are brought together in face-to-face relation, the two micropads form an electrical connection through which the configuration data bit passes from the second die to the first die.