Abstract: An integrated circuit (“IC”) includes a phase-locked loop (“PLL”) with a controllable oscillator embedded in the integrated circuit. A phase-lock circuit provides a lock control signal to the controllable oscillator; and a digital-to-analog converter (“DAC”) provides an oscillator adjustment signal to the controllable oscillator according to a digital code. The digital code is generated by an adjustment circuit configured in the fabric of a programmable logic device, or embedded in the IC, for example. In a particular embodiment, the DAC adjusts the PLL to reduce differential mode voltage in the phase-lock circuit.

Abstract: A packaged semiconductor device uses built-in self test to characterize voltage between points within the semiconductor die during a current discontinuity generated in the semiconductor die. The semiconductor die is operated to generate a current discontinuity, or several sequential current discontinuities, and the voltage is measured with an on-chip ADC. Measuring the voltage within the semiconductor die, rather than measuring at external test points, provides a more accurate prediction of device operation. Multiple test points are measured using a multiplexer, multiple ADCs, or by reconfiguring an FPGA. Impedance versus frequency information of the greater power distribution system connected to the semiconductor die is obtained by transforming the voltage and current through the semiconductor die measured during a current discontinuity.

Abstract: Half cells of single-event-upset-tolerant memory cells are offset by at least two rows in a memory array. Offsetting the half cells separates them to avoid simultaneous damage to both half cells from a high-energy particle that could otherwise alter multiple nodes and corrupt the data state of the memory cell. Separating the half cells by at least two rows avoids corruption that could occur if diagonally arranged half cells were hit by a high-energy particle. In a particular embodiment, offset half cells are used at the top and bottom, respectively, of two adjacent columns of memory half cells.

Abstract: Ground bounce noise in a digital system is evaluated using a weighted average simultaneous switching output (“WASSO”) on an I/O bank of a digital switching device, such as a field programmable gate array (“FPGA”). The WASSO allows a designer to normalize output drivers having different characteristics on a single I/O bank. In a further embodiment, a simultaneous switching output allowance (“SSO allowance”) is calculated using scaling factors derived from values assumed in the creation of published SSO information and predicted actual values of the device in a digital system that are not represented in tables of published SSO guidelines. The SSO allowance is used in conjunction with WASSO values of adjacent I/O banks to evaluate ground bounce for adjacent I/O banks.

Abstract: A system and method for measuring the timing requirements of a sequential logic element of a programmable logic device. The sequential logic element has a first data terminal, an output terminal, and a clock terminal. A first synchronous element is coupled to the data terminal through a first delay element. The first synchronous element is clocked by a clock signal and receives an alternating test signal. A second synchronous element is coupled to the clock terminal through a second delay element of an input-output block. The second synchronous element is also clocked by the clock signal and receives the alternating test signal. The output terminal of the sequential logic element is monitored by a tester or by logic configured in the fabric of the programmable logic device to determine when the logic state changes as the delay of the first or second delay element is selectively varied.

Abstract: A programmable logic device includes a block random access memory (“BRAM”) that is split into two first in, first out (“FIFO”) memory arrays. Two sets of FIFO control logic and FIFO ports are associated with a single BRAM so that the BRAM can be operated as memory buffers for two independent FIFO memory systems.

Abstract: A decision feedback equalization (“DFE”) technique is suitable for use in a serializer-deserializer (“SERDES”) receiver in an integrated circuit (IC). The IC has a summing node coupled to a return-to-zero (“RTZ”) data latch register. The RTZ data latch register has a first (“even”) series of RTZ data latches and a second (“odd”) series of RTZ data latches. A first even tap is coupled to the first even RTZ data latch and provides a feedback signal to the summing node on a first portion of a local clock cycle. A first odd tap is coupled to the first odd RTZ data latch and provides an odd feedback signal to the summing node on a second portion of the local clock cycle.

Abstract: Polysilicon or other material is directionally trimmed using two layers of photoresist and a photoresist etching process, such as ashing. A first layer of photoresist is patterned on a wafer. Portions of the first patterned photoresist are covered with a second layer of photoresist. The photoresist is trimmed to reduce the size of the exposed portions of the first patterned photoresist without reducing the size of the covered portions of the first patterned photoresist. The second layer of photoresist is removed. The selectively etched patterned first layer of photoresist is used as a process mask to define a structure in the underlying material. In a particular embodiment, the second photoresist covers endcap portions of gate photoresist. Directional trimming reduces the width of a polysilicon gate structure (i.e. gate length) over an active area of an FET, without reducing the length of original first patterned photoresist.

Abstract: A differential flip-flop (400) has an output stage (402) with first and second input terminals (X1, X2), first and second output terminals (Q, Qb), a first voltage supply terminal (Vss), a first transistor (435) having a first current-handling terminal connected to the first output terminal (Q), a second current-handling terminal connected to the second output terminal (Qb), and a first control terminal connected to a clock signal (C). A second transistor has a third current-handling terminal connected to the first output terminal (Q), a fourth current-handling terminal connected to the voltage supply terminal (Vss), and a second control terminal connected to a first input terminal (X1) of the output stage. A third transistor (440) has a fifth current-handling terminal connected to the first output terminal (Q), a sixth current-handling terminal connected to the voltage supply terminal (Vss), and a third control terminal connected to the second output terminal (Qb).

Abstract: A configurable logic block (“CLB”) in a programmable logic device (“PLD”), such as a complex programmable logic device (“CPLD”) or a field programmable gate array (“FPGA”), routes a timing signal, such as an external clock signal, through the CLB to provide a selected delay. The timing signal is routed through selected fast or slow pins of look-up tables (“LUTs”) in the CLB. CLBs are widely available in the PLD, allowing many timing signals to be delayed, and can be configured to account for board-specific or component-specific delays.

Abstract: A programmable logic device includes a block random access memory (“BRAM”) with an embedded first in, first out (“FIFO”) controller. Embedding the FIFO logic in silicon, rather than configuring it in the fabric of the programmable logic device, provides a reliable, high-speed asynchronous FIFO memory system.

Abstract: A buffer memory status detection circuit has a binary logic gate (e.g. an OR gate) coupled to a comparator output signal that is asserted when a sum of a first address pointer of a FIFO memory array plus a first offset equals a second address pointer, and to a reset signal. Binary logic provides a binary output (i.e. “0” or “1”) in a first clock domain to two synchronization registers in series that convert the output to a second clock domain. An optional pipeline register improves timing of the output in the second clock domain, and is particularly desirable for use with high-speed clocks.

Abstract: A system for gray-code counting in an integrated circuit such as a programmable logic device uses a binary adder coupled to a binary counter output and to a selected binary offset value. The binary adder provides a binary sum that is converted to a gray code value by a binary-to-gray converter. The gray code value represents the binary sum output.

Abstract: An integrated circuit having an embedded first-in, first-out (“FIFO”) memory system uses an embedded block random access memory (“BRAM”). Counters operate in both the read and write clock domains. A binary adder adds a first selected offset value and to a first pointer address, and the sum is converted to a first gray code value. The first gray code value is compared to a second gray code value that represents a second pointer address. If the first gray code value equals the second gray code value, the output of the comparator is provided to a logic block that produces a status flag (e.g. ALMOST FULL or ALMOST EMPTY) in the correct clock domain.

Abstract: A pump-over fermentation tank has a valve between the pump-over chamber and fermentation chamber providing multi-directional diffusion of the pump-over liquid into the fermentation or extraction chamber. The valve is opened slowly for irrigation of the fermentation cap and is opened rapidly to achieve mixing of the contents in the fermentation chamber. The valve is self-centering in the near-closed position, and in a particular embodiment has diffusers on the perimeter of the valve to direct the pump-over liquid to different regions of the surface of the contents in the fermentation chamber.

Abstract: A two etchant etch method for etching a layer that is part of a masked structure is described. The method is useful, for example, in microelectrical mechanical system (MEMS) applications, and in the fabrication of integrated circuits and other electronic devices. The method can be used advantageously to optimize a plasma etch process capable of etching strict profile control trenches with 89°+/−1° sidewalls in silicon layers formed as part of a mask structure where the mask structure induces variations in etch rate. The inventive two etchant etch method etches a layer in a structure with a first etchant etch until a layer in a fastest etching region is etched. The layer is then etched with a second etchant until a layer in a region with a slowest etch rate is etched. A second etchant may also be selected to provide sidewall passivation and selectivity to an underlying layer of the structure.

Abstract: The invention has multiple embodiments and applications including a digitally tunable laser source, a tapered waveguide, a lensed waveguide, and a tunable laser array. Also described are methods for making and tuning these devices. The laser source includes materials with negative index of refraction dependence on temperature and with temperature independent coincidence between resonator modes and a set of specified frequencies such as DWDM channels in telecommunications applications. The free spectral range may be adjusted to equal a rational fraction of the specified frequency interval. An advantageous embodiment of a tapered waveguide may be used to efficiently couple different size waveguides, such as in a resonator containing both a semiconductor diode amplifier waveguide and a planar waveguide structure for coupling to an optical fiber.

Abstract: An optical switch for manipulating a plurality of input optical signals incident thereupon to split one or more optical signal channels from the plurality of input optical signals. The optical switch includes an optical filter having a first reflective region and a second reflective region. One of the first and the second reflective regions is adapted with a wavelength selective filter that is capable of separating one or more optical signal channels from the input optical signal. A translating mechanism cooperates with the optical filter and is adapted to translate the optical filter in a plane substantially parallel to one of the first reflective region and the second reflective region between a first position and a second position. The translation of the optical filter causes at least one of the one or more optical signal channels to be separated from the optical signal and directed in a second direction.