Abstract: An SEU immune flip-flop includes a master stage data latch having an input, an output, a clock input, being transparent in response to a clock signal first state and being latched in response to a clock signal second state, a slave stage data latch having an input coupled to the master stage data latch output, an output, a scan output, a slave latch clock input, a scan slave latch having an input coupled to the slave stage data latch scan output, an output, and a clock input, being transparent in response to the clock signal second state and being latched in response to the clock signal first state. The slave stage data latch includes a switched inverter disabled when the slave latch is in a transparent state and enabled when the slave latch is in a latched state having a time delay longer than an SEU time period.

Abstract: In one embodiment, a phase locked loop (PLL) circuit in a device includes selectable feedback paths and a multiplexer. An internal feedback path is adapted to pass a first input clock signal to the PLL circuit during a low power operation mode of the device and an external feedback path is adapted to pass a second input clock signal to the PLL circuit during a normal operation mode of the device. The multiplexer is provided for selecting between the internal and external feedback paths.

Abstract: A phase locked loop (PLL) circuit is provided with selectable feedback paths. In one example, a method of operating a device includes passing a clock signal provided by a PLL circuit of the device through an internal feedback path of the PLL circuit to provide a first input signal to the PLL circuit while at least one external circuit of an external feedback path of the device is disabled during a low power operation mode of the device. The method also includes detecting a lock between the first input signal and a reference signal during the low power operation mode. The lock indicates that the clock signal is operating at a frequency used during a normal operation mode of the device. The method also includes passing the clock signal through the external feedback path to provide a second input signal to the PLL circuit.

Abstract: A programmable logic device (PLD) is disclosed that includes a non-volatile memory; a shadow register; and a data shift register (DSR) configurable to receive control information from an external programming tool, wherein the DSR is configured to shift the control information into the shadow register if the PLD is in a first programming mode, the PLD being configurable to operate in the first programming mode using the control information stored in the shadow register without the control information being stored in the non-volatile memory.

Abstract: Techniques are provided to reduce glitches at an output signal node when a device is switched to and from a low power operation mode. In one example, a method of operating a device includes providing power to operate a signal source of the device during a normal operation mode of the device. The method also includes passing an output signal from the signal source through a signal path to an output node during the normal operation mode. The method also includes receiving an operation mode signal to switch the device from the normal operation mode to a low power operation mode. The method also includes disabling the signal path to prevent glitches from appearing at the output node during the switch from the normal operation mode to the low power operation mode. The method also includes continuing providing power to the signal source until after the signal path is disabled.

Abstract: A flexible delay cell architecture and related methods are provided that may be used, for example, with input/output (I/O) blocks of a programmable logic device (PLD). In one implementation, a PLD includes a delay cell comprising a plurality of delay elements. The delay elements are adapted to delay an input signal to provide an output signal according to a delay setting corresponding to a number of the delay elements. The PLD also includes a register adapted to store the delay setting. The PLD further includes an edge monitor adapted to signal whether an edge transition of the output signal has occurred during a time window. In addition, the PLD includes logic adapted to adjust the delay setting stored by the register in response to the edge monitor signaling the edge transition.

Abstract: In one embodiment, a programmable logic device includes a plurality of programmable logic blocks and a plurality of slices within each of the programmable logic blocks. At least one programmable logic blocks includes a first slice not adapted to provide register functionality or RAM functionality, a second slice adapted to provide register functionality but not RAM functionality, and a third slice adapted to provide register functionality and RAM functionality. Control logic within the programmable logic block is adapted to provide control signals at the programmable block level and at the slice level.

Abstract: In one embodiment of the invention, a programmable logic device includes a plurality of programmable logic blocks and a plurality of dual-slice logic blocks within a programmable logic block. A dual-slice logic block includes a first slice including at least two lookup tables (LUTs); a second slice including at least two LUTs; and a routing circuit coupled to each of the LUTs within the first and second slices. The routing circuit is adapted to share outputs of the dual-slice logic block among the LUTs. In another embodiment of the invention, the dual-slice logic block includes a second routing circuit coupled to each of the LUTs within the first and second slices. The second routing circuit is adapted to share inputs of the dual-slice logic block among the LUTs.

Abstract: Systems and methods provide programmable logic block architectures and routing architectures for the programmable logic blocks. For example, in accordance with an embodiment of the present invention, a programmable logic device includes a plurality of programmable logic blocks and a plurality of logic block slices within each of the programmable logic blocks. A first routing circuit provides global signal routing within the programmable logic device for the corresponding programmable logic block. A first input routing circuit receives signals from the first routing circuit and routes the signals to the logic block slices within the corresponding programmable logic block.

Abstract: In one embodiment of the invention, a clock-and-data-recovery (CDR) system has a multi-phase clock generator that generates a plurality of phase-offset clock signals and one or more channel circuits, each receiving a (different) input data signal and all of the phase-offset clock signals and generates an output data stream and a recovered clock signal. Each channel circuit has a plurality of data registers (e.g., flip-flops), each receiving the input data signal at its clock input port and a different one of the phase-offset clock signals at its data input port, such that the flip-flop is triggered at each (rising) edge in the input data signal. The channel circuit processes the outputs from the different flip-flops to select an appropriate phase-offset clock signal for use in sampling the input data signal to generate the output data stream, where the recovered clock signal is generated from the selected phase-offset clock signal.

Abstract: In one embodiment of the invention, a programmable logic device comprises configuration memory adapted to store configuration data and a plurality of programmable logic blocks. At least one programmable logic block includes a plurality of dual-slice logic blocks, each dual-slice logic block including first and second slices, each slice including at least two lookup tables (LUTs) and a register. The programmable logic block further includes control logic adapted for selecting control signals separately at a programmable block level, a dual-slice block level, and a register level, the control logic responsive to configuration data stored within the configuration 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: 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 logic block slice architectures and programmable logic block architectures along with control logic architectures in accordance with embodiments of the present invention. For example, in accordance with an embodiment of the present invention, a programmable logic device includes a plurality of programmable logic blocks and a plurality of logic block slices within each of the programmable logic blocks, with each of the logic block slices having at least a first and a second slice each having at least a first lookup table. At least one of the programmable logic blocks includes at least a first logic block slice, a second logic block slice, and a third logic block slice, with the first logic block slice being a logic block slice type different from the second logic block slice, and the third logic block slice being a logic block slice type different from the first and second logic block slices.

Abstract: Systems and methods are disclosed herein to provide dual slice architectures and programmable logic block architectures along with control logic architectures in accordance with embodiments of the present invention. For example, in accordance with an embodiment of the present invention, a programmable logic device includes a plurality of programmable logic blocks and a plurality of dual-slice logic blocks within each of the programmable logic blocks, wherein each dual-slice logic block includes a first and a second slice each having at least a first lookup table, with a first one of the dual-slice logic blocks of a logic block slice type different from a second one of the dual-slice logic blocks, and a third one of the dual-slice logic blocks of a logic block slice type different from the first and second dual-slice logic blocks.

Abstract: Systems and methods are disclosed herein to provide logic block slice architectures and programmable logic block architectures along with control logic architectures in accordance with embodiments of the present invention. For example, in accordance with an embodiment of the present invention, a programmable logic device includes a plurality of programmable logic blocks, with at least one of the programmable logic blocks having at least a first, a second, and a third logic block slice of different logic block slice types.

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, a clock-and-data-recovery (CDR) system has a multi-phase clock generator that generates a plurality of phase-offset clock signals and one or more channel circuits, each receiving a (different) input data signal and all of the phase-offset clock signals and generates an output data stream and a recovered clock signal. Each channel circuit has a plurality of data registers (e.g., flip-flops), each receiving the input data signal at its clock input port and a different one of the phase-offset clock signals at its data input port, such that the flip-flop is triggered at each (rising) edge in the input data signal. The channel circuit processes the outputs from the different flip-flops to select an appropriate phase-offset clock signal for use in sampling the input data signal to generate the output data stream, where the recovered clock signal is generated from the selected phase-offset clock signal.

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 initialize memory blocks of a programmable logic device. For example in accordance with an embodiment of the present invention, a system bus extension is provided for the memory blocks that functions as a unidirectional broadcasting write bus. A read bus may also be provided to read data stored in the memory blocks.