Abstract: Various techniques are provided to efficiently synchronize clock and data signals in programmable logic devices (PLDs). In one example, a method comprises configuring an intellectual property (IP) block of the PLD to receive a first clock signal and a first data signal at a first component of the IP block, determining a delay associated with the first clock signal between a first input and the first component, configuring a programmable logic cell (PLC) to receive a second clock signal and output the first data signal to the IP block, determining a delay period to synchronize the first clock signal and the first data signal at the first component of the IP block, and configuring an adjustable delay element to apply the delay period to the second clock signal to synchronize the first clock signal and the first data signal at the first component of the IP block.

Abstract: Various techniques are provided to implement dual power supplied memory cells and deterministic reset thereof for programmable logic devices. In one example, a programmable logic device (PLD) includes a configuration memory including an array of memory cells arranged in rows and columns. The PLD further includes a power supply circuit coupled to the configuration memory and configured to selectively couple, based on a reset control signal, a power supply to a first power supply line coupled to the array of memory cells. The array of memory cells is reset if the power supply is coupled to the first power supply line. The power supply circuit is further configured to provide power on a second power supply line to the array of memory cells. Related methods and devices are provided.

Abstract: Various techniques are provided for selectively operating a memory block in full power or half power modes. In one example, a system comprises a memory block configured to be selectively operated in a full power mode or a half power mode. The memory block comprises an input/output port. The memory block further comprises a first sub-block configured to be powered on during the full power mode and during the half power mode. The memory block further comprises a second sub-block configured to be powered on during the full power mode and powered off during the half power mode. The memory block further comprises routing hardware configured to pass data between the input/output port and the first and second sub-blocks. Additional systems and methods are also provided.

Abstract: Systems and methods for providing adaptive power on reset (POR) signals for use with programmable logic devices (PLDs) and/or other semiconductor devices are disclosed. An example adaptive POR signal generator includes a logic device configured to detect a first supply voltage ramp traversal across a first threshold ramp voltage, detect a second supply voltage ramp traversal across a second threshold ramp voltage, and generate a POR signal based, at least in part, on a nominal operating voltage associated with the power supply and/or the supply voltage and/or on a ramp time associated with the first and second supply voltage ramp traversals. The second threshold ramp voltage is higher than the first threshold ramp voltage and the first and second threshold ramp voltages are lower than the nominal operating voltage.

Abstract: Systems and methods for providing adaptive power on reset (POR) signals for use with programmable logic devices (PLDs) and/or other semiconductor devices are disclosed. An example adaptive POR signal generator includes a logic device configured to detect a first supply voltage ramp traversal across a first threshold ramp voltage, detect a second supply voltage ramp traversal across a second threshold ramp voltage, and generate a POR signal based, at least in part, on a nominal operating voltage associated with the power supply and/or the supply voltage and/or on a ramp time associated with the first and second supply voltage ramp traversals. The second threshold ramp voltage is higher than the first threshold ramp voltage and the first and second threshold ramp voltages are lower than the nominal operating voltage.

Abstract: Field programmable gate arrays (FPGA's) may be structured in accordance with the disclosure to have a register-intensive architecture that provides, for each of plural function-spawning LookUp Tables (e.g. a 4-input, base LUT's) within a logic block, a plurality of in-block accessible registers. A register-feeding multiplexer means may be provided for allowing each of the plural registers to equivalently capture and store a result signal output by the corresponding, base LUT of the plural registers. Registerable, primary and secondary feedthroughs may be provided for each base LUT so that locally-acquired input signals of the LUT may be fed-through to the corresponding, in-block registers for register-recovery purposes without fully consuming (wasting) the lookup resources of the associated, base LUT. A multi-stage, input switch matrix (ISM) may be further provided for acquiring and routing input signals from adjacent, block-interconnect lines (AIL's) and/or block-intra-connect lines (e.g.

Abstract: Field programmable gate arrays (FPGA's) may be structured in accordance with the disclosure to have a hierarchical general interconnect architecture in which: (1) reliance on single-length general interconnect lines is avoided; (2) the next greater length of general interconnect line is at least double-reach length (triple span); and (3) yet greater lengths of general interconnect line (e.g., Deca-Reach Length, or 11-span) can feed signals into logic blocks indirectly through switching resources of the shorter length, general interconnect line rather than feeding such signals directly into the logic blocks through their own respective switching resources. Additionally, the yet greater lengths of general interconnect line (e.g., Deca-Reach Length) have a fewer number of signal tap points on them than the number of logic blocks spanned by such longer ones of the general interconnect lines.

Abstract: A field programmable gate array (FPGA) has plural columns of run-time memory provided in each of one or more partitions. Each column of run-time memory has a plurality of configurable memory blocks (CMB's). Each CMB is programmably configurable at least into a shallow-and-widest mode where data words have a maximum bit width and into a deep-and-narrowest mode where data words have a minimum bit width. Each CMB spans plural interconnect buses and the bits of its widest data words are distributed among the spanned interconnect buses. When a deep-and-narrow mode is invoked, CMB's of alternate columns operate in complementary fashion so that bits of narrowed words from one CMB move through a first subset of the interconnect buses while bits of narrowed words from a second CMB, in an alternate column, move through a second subset of the interconnect buses, where the second subset is mutually exclusive of the first subset of the interconnect buses.

Abstract: An input/output buffer is provided which can be used to make an integrated circuit selectively compatible with one of a number of interface types, such as PCI, GTL, PECL, ECL and SSTI. The input buffer portion includes a first pair of CMOS transistors for driving the output (OUT) between the VSS and VDD rails similar to CMOS logic. Switching circuitry includes transistors which drive gates of the CMOS transistors to set the output (OUT) with a current level and a voltage level depending on a desired output drive current and voltage.

Abstract: An input/output buffer is provided with an output buffer portion which can be used to make an integrated circuit selectively compatible with one of a number of interface types, such as PCI, GTL, PECL, ECL and SSTI. An output buffer portion has an input for receiving an output signal node (D) where components on the integrated circuit provide an output signal for connecting to external circuits at an output pad (PAD). The input buffer includes switching circuitry driving the gates of multiple CMOS buffer transistors to provide sufficient current for rapid switching, and limit current after switching to prepare for a subsequent output transition. The switching circuitry includes components to prevent damage to low voltage transistors used in the output buffer should the output pad (PAD) voltage exceed VDD, or should charge buildup occur on the common well of PMOS transistors used in the output buffer exceed VDD.

Abstract: An electrostatic discharge ESD protection circuit is provided which can selectively be set to operate with a buffer which is programmably controlled to be compatible with different types of circuitry, such as PCI, GTL, or PECL circuits. The ESD circuit includes a lateral NPN BJT transistor which provides a path to ground during ESD without experiencing the gate oxide damage of a typical MOS type device. Additional BJTs are included in Darlington-pair configuration to connect the pad to the lateral BJT during an ESD event and not experience oxide damage. An additional BJT is included along with a series of diode connected transistors to selectively clamp the pad voltage. The pad voltage is clamped to a desired value by controlling fuses connecting the series of diode connected transistors.

Abstract: A programmable optimized-distribution logic allocator enhances the speed, silicon utilization, logic efficiency, logic utilization, and scalability of very high-density CPLDs including the logic allocator. The programmable optimized-distribution logic allocator provides an optimized number of product terms to each I/O pin of the CPLDS and the same uniform number of product terms as feedback. However, no product terms are permanently connected to either a particular macrocell or a particular I/O pin. The programmable optimized-distribution logic allocator includes a multiplicity of router elements where each router element steers a sum of a selected number of sum-of-product terms from a PAL structure, i.e, a selected number of logic product-term clusters, to a programmably selected logic macrocell. Specifically, the programmable optimized-distribution logic allocator has a plurality of input lines, a plurality of output lines and a plurality of programmable router elements.

Abstract: Configurable interconnect resources of field programmable gate arrays (FPGA's) are tested by configuring at least some of the lookup tables (LUT's), registers and input signal acquirers to implement one or more sequential state machines that feed back their current states via at least some of the interconnect conductors to the inputs of the LUT's. The fedback signals are decoded by the LUT's for defining next-states of the one or more sequential state machines. Each sequential state machine may be programmed to sequentially step through a number of unique states, where the unique states challenge capabilities of the interconnect conductors to toggle through combinations of different signal levels. The sequential state machines are exercised to sequentially step through plural ones of their unique states.

Abstract: A band gap reference includes circuitry providing a reference voltage (VDIODE) at 1.0 volt or below to provide a stable reference for 1.3 volt or lower circuits, which would otherwise not function accurately with a typical band gap reference of 1.2 volts. The band gap reference includes an op-amp equally driving the gate of various current source transistors. A first current source drives a BJT transistor connected in a diode fashion, while a second current source drives a further diode connected BJT transistor through a resistor. An output VDIODE is provided from a further resistor connected to two additional current sources. The first of these current sources is driven by the op-amp output to increase output with temperature, while the second of these current sources is driven by a replicating op-amp connected to a resistor providing current decreasing with temperature, both current sources functioning to provide a stable low voltage VDIODE on the resistor with variations in temperature and supply voltage.

Abstract: An input/output buffer is provided with an output buffer portion which can be used to make an integrated circuit selectively compatible with one of a number of interface types, such as PCI, GTL, PECL, ECL and SSTI. The output buffer portion has an input connected to an output signal node (D) where components on the integrated circuit provide an output signal for connecting to external circuits at an output pad (PAD). Control power switches driving the gates of multiple CMOS buffer transistors to provide sufficient current for rapid switching, and limit current after switching to prepare for a subsequent output transition. The CMOS buffer transistors are selectively enabled to control output drive current. Selectable pull-up and pull-down reference circuits provide references (VRFPU, VRFPPU, VRFPD and VRFPPD) to control the current of the buffer output during transition of the output, while maintaining the output voltage level at a desired voltage with minimal current level after transition.

Abstract: An input/output buffer is provided with input buffer circuitry which can be used to make an integrated circuit selectively compatible with one of a number of interface types, such as PCI, GTL, PECL, ECL and SSTI. The input buffer portion includes a CMOS transistors for driving the output (OUT) between the VSS and VDD rails similar to CMOS logic. The voltage and current on the output of the input buffer as controlled by the CMOS transistors is clamped to levels depending on a mode select signal applied to selectively provide different output levels compatible with PCI, GTL, PECL, ECL and SSTI signals.

Abstract: Field programmable gate arrays (FPGA's) may be structured in accordance with the disclosure to have a hierarchical general interconnect architecture in which: (1) reliance on single-length general interconnect lines is avoided; (2) the next greater length of general interconnect line is at least double-reach length (triple span); and (3) yet greater lengths of general interconnect line (e.g., Deca-Reach Length, or 11-span) can feed signals into logic blocks indirectly through switching resources of the shorter length, general interconnect line rather than feeding such signals directly into the logic blocks through their own respective switching resources. Additionally, the yet greater lengths of general interconnect line (e.g., Deca-Reach Length) have a fewer number of signal tap points on them than the number of logic blocks spanned by such longer ones of the general interconnect lines.

Abstract: An input/output buffer is provided with an output buffer portion which can be used to make an integrated circuit selectively compatible with one of a number of interface types, such as PCI, GTL, PECL, ECL and SSTI. An output buffer portion has an input for receiving an output signal node (D) where components on the integrated circuit provide an output signal for connecting to external circuits at an output pad (PAD). The signal from the PAD is further fed back through the input buffer portion which programmably set to operate in a PCI, PECL or GTL mode to control a node (INB). The node (INB) is used to control power switches driving the gates of CMOS buffer transistors to provide sufficient current for rapid switching, and limit current after switching to prepare for a subsequent output transition.

Abstract: A Variable Grain Architecture is disclosed wherein Variable Grain Blocks (VGB's) are wedged together in mirror opposition to one another to define super-VGB structures. The super-VGB structures are arranged as a matrix within an FPGA device. Each VGB includes progressive function synthesizing layers for forming more complex function signals by folding together less complex function signals of preceding layers. A function spawning layer containing a set of function spawning lookup tables (LUT's) is provided near the periphery of the corresponding super-VGB structure. In one case, the function spawning layer is L-shaped and includes a symmetrical distribution of Configurable Building Blocks. A signal-acquiring layer interfaces with adjacent interconnect lines to acquire input terms for the LUT's and controls. A decoding layer is interposed between the signal-acquiring layer and the function spawning layer for providing strapping and intercept functions.

Abstract: A field-programmable gate array device (FPGA) having plural rows and columns of logic function units (VGB's) further includes a plurality of embedded memory blocks, where each memory block is embedded in a corresponding row of logic function units. Each embedded memory block has a registered address port for capturing received address signals in response to further-received, address-validating clock signals. Interconnect resources are provided for conveying the address-validating clock signals to address-changing circuitry so that a next address can be generated safely in conjunction with the capturing by the registered address port of a previous address signal.