Abstract: A programmable logic block within a programmable logic device includes at least two interconnected slices, each of the interconnect slices including at least two interconnected lookup tables. Each interconnected lookup table is adapted to receive input signals from a routing structure and to provide a LUT output signal. At least one of the slices includes a register adapted to register the LUT output signal of a lookup table and at least another of the slices includes fewer such registers than lookup tables.

Abstract: Systems and methods are disclosed herein to provide an improved approach to the configuration of integrated circuits such as programmable logic devices (PLDs). In one example, a method of operating a PLD includes receiving a configuration data bitstream at a slave serial peripheral interface (SPI) port of a PLD from a master SPI port of a first external device. The method also includes passing the configuration data bitstream through the PLD from the slave SPI port of the PLD to a master SPI port of the PLD. The method further includes providing the configuration data bitstream from the master SPI port of the PLD to a slave SPI port of a second external device.

Abstract: A programmable logic device, in accordance with an embodiment, includes a first terminal; an input buffer having a buffer input terminal and a buffer output terminal; and a multiplexer coupled to the first terminal and to the input buffer, wherein the multiplexer is adapted to selectively couple either the first terminal to the buffer input terminal or couple the buffer output terminal to the buffer input terminal.

Abstract: Techniques for synchronizing data signals and clock signals of a programmable logic device (PLD) are provided. In one example, a method includes preparing an initial configuration of the PLD identifying a plurality of data paths associated with the data signals and a plurality of clock paths associated with the clock signals. The method also includes identifying a hold time violation associated with at least one of the data paths, wherein at least one of the clock signals is used to synchronize the data path. The method further includes selectively adjusting a delay period of a delay element of at least one of the clock paths associated with the clock signal to attempt to correct the hold time violation without concurrently attempting to correct any setup time violation associated with the data path.

Abstract: A programmable logic device (PLD) such as a field programmable gate array (FPGA) has a power-down mode of operation that reduces power consumption during standby or idle periods for the PLD. In one embodiment, the PLD includes a switch such as an internal power supply operable to provide power to the logic core of the PLD, such as the programmable logic blocks, routing structure, and volatile configuration memory. The internal power supply powers down the logic core in response to assertion of a power-down signal, while power is maintained to other circuitry of the PLD.

Abstract: Systems and methods are disclosed herein to provide improved non-volatile storage techniques for programmable logic devices. For example, in accordance with an embodiment of the present invention, a programmable logic device includes a plurality of logic blocks, a plurality of input/output blocks, and a volatile memory to store data within the programmable logic device, with configuration memory adapted to store first configuration data for configuration of the logic blocks, the input/output blocks, and the volatile memory of the programmable logic device. The programmable logic device further includes a non-volatile memory adapted to store data provided from the volatile memory.

Abstract: In one embodiment, a programmable logic device includes: a multiplexer adapted to select a compressed configuration bitstream from a plurality of external serial interface memories; a serial interface processor adapted to command the bitstream selection by the multiplexer; and a bitstream decompressor adapted to decompress the selected configuration bitstream into a decompressed configuration bitstream.

Abstract: In one embodiment of the invention, an integrated device has interface circuitry that includes a dynamic monitor that monitors the relative potential between (at least) two different power supplies to enable the device to react to over-voltage conditions such that appropriate selections can be made for which power supplies are selected for different components in the interface circuitry, such as output drivers and input receivers. The dynamic monitor enables over-voltage protection to be automatically implemented before the device has been configured, such as during the device's power-on state.

Abstract: Systems and methods are disclosed herein to provide techniques for providing programmable identification codes (IDCODE) for PLDs. For example, in accordance with an embodiment of the present invention, a programmable logic device includes a first non-volatile memory adapted to store a first identification code of the programmable logic device, and a second memory adapted to store a second identification code of the programmable logic device. A control circuit selects between the first identification code stored in the first non-volatile memory and the second identification code stored in the second memory to provide as an identification code for the programmable logic device.

Abstract: Systems and methods disclosed herein provide for variable data width memory. For example, in accordance with an embodiment of the present invention, a technique for doubling a width of a memory is disclosed, without having to increase a width of the internal data path or the number of input/output pads.

Abstract: In accordance with an embodiment of the present invention, a programmable logic device (PLD, such as a field programmable gate array (FPGA)) includes a plurality of input/output blocks having boundary scan cells that are adapted to precondition registers within a logic area of the programmable logic device with desired signal values prior to release of control of the input/output blocks to user-defined logic provided by a reconfiguration.

Abstract: A programmable logic device includes, in accordance with one embodiment, a plurality of logic blocks; an interconnect structure adapted to route signals among the logic blocks; and a memory for storing data within the programmable logic device. A first set of the logic blocks are configured as logic analyzer trigger units adapted to each receive one or more input signals from within the programmable logic device and provide a corresponding trigger unit output signal. A portion of the memory stores a logic analyzer trigger expression, with the trigger unit output signals provided to the memory as address signals for the trigger expression.

Abstract: A buffer for a programmable logic device has programmable current sink and source circuitry and an independently programmable common-mode voltage reference source. An amplifier, responsive to a common-mode voltage detector and the voltage reference source, forces a common-mode voltage of an output signal from the buffer to approximate the voltage from the common-mode voltage reference source.

Abstract: Systems and methods provide register data retention techniques for a programmable logic device in accordance with one or more embodiments of the present invention. For example, in accordance with an embodiment, a method includes programming routing resources between programmable logic and registers of a programmable logic device to provide a data path for data prior to a reprogramming; transferring data from the programmable logic, prior to the reprogramming, to the registers via the data path to store the data within the programmable logic device during the reprogramming; reprogramming the programmable logic device, wherein the reprogramming provides a reprogrammed data path between the programmable logic and the registers of the programmable logic device; and transferring the data within the programmable logic device from the registers via the reprogrammed data path for use by the programmable logic after the reprogramming of the programmable logic device has been completed.

Abstract: A channel-alignment circuit has a controller and a plurality of channel-alignment blocks. Each channel-alignment block synchronizes two or more channels. The controller coordinates the synchronization of channels by the blocks such that (i) channels in each of one or more groups of two or more blocks are synchronized, and (ii) each group of blocks is synchronized independently of any other group.

Abstract: Systems and methods are disclosed herein to provide improved I/O techniques. For example, in accordance with an embodiment of the present invention, an integrated circuit includes a driver that receives data signals and provides an output signal based on the data signals, with the driver having a plurality of transistors with a first set of the plurality of transistors adapted to provide a first logical value as the output signal and a second set of the plurality of transistors adapted to provide a second logical value as the output signal based on the data signals. A sequencing circuit provides the data signals to the driver such that the first set of the plurality of transistors is switched on before the second set of the plurality of transistors is switched off, and the second set of the plurality of transistors is switched on before the first set of the plurality of transistors is switched off.

Abstract: Systems and methods are disclosed herein to provide signal monitoring techniques. For example, in accordance with an embodiment of the present invention, an integrated circuit includes a phase detector circuit that receives an input signal and samples the input signal to provide binary state signals. A signal monitoring circuit decodes the binary state signals and provides at least one output signal indicating for the input signal path equalization and/or duty cycle distortion.

Abstract: In one embodiment, a memory is provided that includes: a memory cell array adapted to be programmed with a positive voltage from a positive-negative node and to be erased with a negative voltage from the positive-negative node; a negative voltage blocking circuit; and a positive voltage source operable coupled to the negative voltage blocking circuit, the positive voltage source operable to provide the positive voltage to the positive-negative node through the negative voltage blocking circuit, wherein the negative voltage blocking circuit is adapted to prevent the negative voltage from coupling from the positive-negative node to the positive voltage source.

Abstract: According to one embodiment of the invention, a method of generating a compressed configuration bitstream for a programmable logic device comprises encoding the most-prevalent data word within the configuration data of the bitstream into a first type of code word; encoding a set of more-prevalent data words within the configuration data into a second type of codeword; and identifying in the compressed bitstream at least some of the data words that are members of the set of more-prevalent data words.

Abstract: Systems and methods are disclosed herein to provide software clock boosting techniques. For example in one embodiment, a method of configuring a programmable logic device includes receiving routed data; performing a software clock boost operation on the routed data to determine and include one or more desired clock delays for circuit elements. The software clock boost operation may include performing a static timing analysis on the routed data; determining a list of the desired clock delays; and modifying the routed data to insert the desired clock delays.