Abstract: In one embodiment of the invention, a programmable logic device such as an FPGA includes a programmable fabric; a JTAG interface operable to receive configuration data for programming the fabric; a SPI interface operable to receive and transmit configuration data for programming the fabric; and circuitry coupled to the JTAG and SPI interfaces. The circuitry is operable, without being configured, to transfer configuration data received at the JTAG interface to the SPI interface for transmission to an external device having a SPI interface, such as a serial flash memory.

Abstract: Systems and methods are disclosed herein to provide improved alignment of output signals of an analog-to-digital converter (ADC). For example, in accordance with an embodiment of the present invention, a method of aligning digital signals appearing on signal paths of a parallel data bus includes sampling the digital signals at a plurality of delay times to obtain a plurality of sample sets, wherein each sample set is associated with a corresponding delay time. A second digital signal that is misaligned with respect to a first digital signal is identified from the sample sets. The delay time required to align the second digital signal with the first digital signal is determined. The delay of the second digital signal is adjusted by the determined delay time.

Abstract: In one embodiment of the invention, a programmable logic block within a programmable logic device includes: a plurality of lookup tables, each lookup table providing a combinatorial output signal; and a plurality of registers, each register being adapted to register a selected one of the combinatorial output signals, wherein the number of registers is less than the number of lookup tables.

Abstract: A first programmable device comprises non-dedicated, programmable resources including programmable logic; dedicated circuitry; a Joint Test Action Group (JTAG) interface adapted to selectively interchange signals with the programmable logic via the dedicated circuitry; and a Serial Peripheral Interface (SPI) interface adapted to (1) selectively interchange signals with the programmable logic via the dedicated circuitry and (2) selectively interchange signals with the JTAG interface via the dedicated circuitry. The JTAG interface is adapted to be connected to a first external device. The SPI interface is adapted to be connected to a second external device. The first programmable device is adapted to transfer signals from the first external device to the second external device via the JTAG interface, the dedicated circuitry, and the SPI interface without relying on any of the programmable resources.

Abstract: In one embodiment, a programmable logic device is provided that includes a memory having memory cells, each memory cell operable to store either a configuration bit or a RAM bit; a masking circuit operable to mask a RAM bit by providing a masking value for the masked RAM bit; an error detection circuit operable to process the configuration bits during operation of the programmable logic device using an error detection algorithm, the error detection circuit calculating a signature that includes configuration bits and masking values; and a comparator operable to compare the signature calculated by the error detection circuit with a correct signature.

Abstract: The configuration architecture for a programmable device, such as an FPGA, includes one or more memory devices connected directly to the FPGA such that the FPGA can be configured with configuration data stored in the memory devices without transmitting the configuration data via a controller connected between any of the memory devices and the FPGA. In one embodiment, the FPGA has an Serial Peripheral Interface (SPI) that is connected to the SPI interface of each of one or more SPI serial flash PROMs operating as boot PROMs. When there are two or more boot PROMs, each PROM stores a portion of the FPGA's configuration data and the FPGA interleaves the data from multiple boot PROMs to generate a serial configuration data bitstream. The present invention enables boot PROMs having different sizes and/or storing different amounts of configuration data to be simultaneously connected to an FPGA to support efficient configuration architectures.

Abstract: The configuration architecture for a programmable device, such as an FPGA, includes one or more memory devices connected directly to the FPGA such that the FPGA can be configured with configuration data stored in the memory devices without transmitting the configuration data via a controller connected between any of the memory devices and the FPGA. In one embodiment, the FPGA has an Serial Peripheral Interface (SPI) that is connected to the SPI interface of each of one or more SPI serial flash PROMs operating as boot PROMs. When there are two or more boot PROMs, each PROM stores a portion of the FPGA's configuration data and the FPGA interleaves the data from multiple boot PROMs to generate a serial configuration data bitstream. The present invention enables boot PROMs having different sizes and/or storing different amounts of configuration data to be simultaneously connected to an FPGA to support efficient configuration architectures.

Abstract: Systems and methods are disclosed for providing output impedance measurement techniques. For example, in accordance with an embodiment of the present invention, a system includes a controller adapted to measure an output impedance of a first circuit that provides an output signal having a first voltage level. The output signal from the first circuit is compared to a plurality of voltage levels provided by the controller, with the controller determining the output impedance of the first circuit based on the results of the comparison.

Abstract: An ASIC conversion of a programmable logic device (PLD) is provided. The PLD includes a plurality of logic blocks coupled together by a PLD routing structure. The ASIC includes a plurality of logic blocks corresponding on a one-to-one basis with logic blocks in the PLD and a routing structure corresponding to the programmable routing structure of the PLD. Vias or traces are selectively placed in the ASIC so that logical behavior of its logic blocks matches that implemented in the PLD and the signal propagation delay through the ASIC matches the delay through the PLD.

Abstract: A memory provides a programmable write port data width and an independently programmable read port data width. The independence between the programmable write port data width and the programmable read port data width is achieved without the use of a third clock domain.

Abstract: A programmable logic device includes a plurality of logic blocks. Each logic block includes a plurality of macrocells, with each macrocell being configurable to register a sum of product term output. In addition, the macrocells within each logic block are arranged from a first macrocell to a last macrocell. Each macrocell is associated with a carry-in and a carry-out signal. The macrocells are configured to support a carry cascade such that the carry-out signal from the first macrocell becomes the carry-in signal for the second macrocell, and so on.

Abstract: A programmable device with logic blocks is configured to cascade product terms from one logic block to another to increase the logical input width of the product terms. Each logic block may produce a plurality of product terms based upon the selection of inputs from a routing structure. Logic blocks configured to receive cascaded product terms includes a plurality of AND gates corresponding to the plurality of product terms.

Abstract: An architecture is disclosed to provide high-speed input/output interface capabilities for programmable devices. One or more configurable input/output circuits are situated between the input/output drivers and the programmable core circuitry of the programmable device. The input/output circuits are optimized for the high-speed requirements of the input/output interface standards, with each input/output circuit configurable to support numerous, different input/output interface standards. The programmable core circuitry may be utilized to support the lower-speed requirements of the input/output interface standards.

Abstract: Systems and methods are disclosed for programmable logic devices requiring a high-speed input/output interface. Hard-macro circuits that are configurable, scalable, and cascadable complement the input/output drivers and the programmable core logic of the programmable logic device. The hard-macro circuits are permanent, high-speed logic circuits that are optimized for the performance requirements of high-speed input/output interface standards. High-speed memory interfaces, clock and data recovery interface standards, source-synchronous interface standards, and system-synchronous interface standards may be supported by the hard-macro circuits.

Abstract: The fuse points within a programmable AND array may be programmed with configuration signals to select for logical signals to form product term outputs in a logic mode. In a switch mode, a subset of these fuse points may be programmed with dynamically-created operating signals to form a cross point switch matrix.

Abstract: A programmable device and method with generic logic blocks. Each generic logic block is configurable to perform product term logic functions and memory functions, such as RAM, dual-port RAM, ROM, CAM, FIFO and switch.

Abstract: A programmable device and method with generic logic blocks. Each generic logic block is configurable to perform product term logic functions and memory functions, such as RAM, dual-port RAM, ROM, CAM, FIFO and switch.

Abstract: A system-level (SLT) of a CPU device is performed in an automated test environment. Each device under test is automatically placed an SLT station and a test is performed at an initial operating speed. A CPU device which passes the test is then automatically removed and placed in a storage container based on that operating speed, also known as a rating (or rated) speed. If the device fails the test, however, then it remains in the test station and the operating speed of the station is adjusted until the device is able to pass the test. Once successful, the device is automatically removed and placed in a storage container based on the operating speed at which it finally was successful. A device which is unable to pass a system-level test at any speed is automatically removed and placed in a reject bin.

Abstract: The FPGA has an array of programmable logic cells (PLCs) surrounded by a ring of programmable input/output cells (PICs). In one embodiment, the pads of each pair of adjacent PICs, as well as internal routing resources of each of the two PICs, are programmably connected to a single global-signal spine, and the spine is programmably connected directly to only half of the perpendicular branches. Each of the branches can then connect to the cells in two adjacent rows/columns of the array to provide a global signal to any of the cells in the array while only using a branch per every two rows/columns of the device. The reduced number of spine-to-branch connections reduces the capacitive loading on the spines, thereby increasing the speed at which global signals can be transmitted. In addition, sharing spines between adjacent PICs reduces the number of spines in the FPGA by half, thereby providing additional layout space for other resources.

Abstract: A programmable logic device, such as an FPGA, is implemented using logic cells that have configurable connection schemes between routing resources and logic element input pins. For example, in one embodiment, each logic cell in the device has a flexible input structure that supports two or more different connection schemes, which may or may not involve input sharing, where each logic cell can be individually programmed for any of the available connection schemes when the device is configured. As such, the device can be efficiently programmed to implement the user's specific circuitry. The invention balances the competing goals of (1) reducing routing requirements by limiting the number of connections between routing resources and logic element input pins and (2) providing minimally constrained programming of logic elements.