Xilinx, Inc.

Taiwan Semiconductor Manufacturing Comp. Ltd.

Justin Gaither

Alan S Roth

Eric Soenen

Justin Shi

Martin Kinyua

Amjad Odet-Allah

Marwan M Hassoun

Ying-Chih Hsu

Alexander L Iles

A regulator includes a controller, a driving unit, a digital-to-analog converter, and a comparator. The controller outputs a digital reference voltage and a control signal responsive to a comparison signal. The driving unit generates an output voltage at a first node responsive to the control signal. The digital-to-analog converter generates an analog reference voltage responsive to the digital reference voltage. The comparator generates the comparison signal based on the analog reference voltage and the output voltage.

Dynamic control loop for switching regulators

A circuit includes an analog-to-digital converter (ADC). The ADC is configured to receive an analog feedback signal and an analog input signal and generate a digital output. The circuit further includes a digital filter configured to filter the digital output and a noise shaper. The noise shaper is configured to truncate the filtered digital output and generate a noise shaper output, and to shape quantization noise generated during truncation. The circuit further includes a pulse width modulation digital-to-analog converter (PWM DAC) configured to process the truncated digital output of the noise shaper output and generate a PWM DAC output.

Noise shaping for digital pulse-width modulators

An apparatus for controlling slew rate is coupled to two adjustable voltage rails. The output of the apparatus is coupled to the gate of a switching element. By employing two adjustable voltage rails, the slew rate of the switching element is proportional to the voltage difference between the first adjustable rail and the second adjustable rail. The slew rate control apparatus can be applied to a variety of switching elements including N channel Field Effect Transistors (NFETs), P channel Field Effect Transistors (PFETs), current mode logic circuits and level shifter circuits.

Apparatus for controlling slew rate

A circuit including an analog-to-digital converter (ADC). The ADC is configured to receive an analog feedback signal and an analog input signal and generate a digital output. The circuit further includes a noise shaper. The noise shaper is configured to truncate the digital output and generate a noise shaper output having a lower number of bits than the digital output, and to shape quantization noise generated during truncation. The circuit further includes a pulse width modulation digital-to-analog converter (PWM DAC). The PWM DAC configured to process the truncated digital output of the noise shaper output and generate a PWM DAC output.

A method of controlling a regulator includes turning on a first driver during a first cycle for a first time period. A second driver is turned on during the first cycle for a second time period. The first and second drivers are off during the first cycle for a third time period. The first time period is adjusted to become an adjusted first time period for a second cycle based on a ratio and a voltage difference between a peak value of the output voltage and a first voltage during the first cycle. The ratio refers to the first time period over the first time period and the second time period.

A noise shaper that compares an input signal to a feedback output signal, which is a truncated version of the input signal, and generates the difference between the two signals (i.e., the error). The noise shaper then integrates the errors by adding to the error multiple of its delayed versions, and quantizes the integrated errors in such a way that the spectrum of the quantization noise is shaped toward high frequencies to be removed by a LC low-pass filter used in conjunction with the noise shaper. The low frequency content of the desired signal is mostly unaffected.

A phase/frequency detector module allows operation as either a phase locked loop or a frequency locked loop. As a phased locked loop (PLL), the phase detector module is configured to decode phase differences between a reference signal and a voltage controlled oscillator (VCO) signal into phase correction signals that are updated at the rate of the VCO signal. An accumulation of the phase correction signals is implemented to form an accumulated phase error signal, which is then sampled at a lower rate than the VCO signal to accommodate slower components of the PLL, such as a digital to analog converter (DAC). As a frequency locked loop (FLL), the phase detector module is configured with frequency counters, so that frequency error may instead be detected. Any reduction of gain caused by the frequency counters is inherently equalized by the phase detector module.

Method and apparatus for a phase/frequency locked loop

A method and system for a programmable input/output transceiver is disclosed. A circuit in accordance with the invention includes a programmable transceiver. The programmable transceiver is configured and/or controlled to support an interface standard. A system according to the present invention includes a programmable transceiver and a field-programmable gate array (FPGA) core coupled to program the programmable transceiver.

Method and system for programmable input/output transceiver wherein transceiver in configurable to support a plurality of interface standards

Method and system for programmable input/output transceiver wherein transceiver is configurable to support a plurality of interface standards

A circuit for buffering data is disclosed. The circuit comprises a first circuit which is coupled to receive a stream of data blocks using a first clock signal. The first circuit removes data blocks, such as idle data blocks or a sequence ordered set of a pair of consecutive sequence ordered sets, from the stream of data blocks to create a first modified data stream which is coupled to a memory device. Finally, a second circuit coupled to the memory device generates a second modified data stream using a second clock signal. The second modified data stream preferably comprises the data blocks of the first modified data stream and idle data blocks inserted among the data blocks of the first modified data stream. Methods of buffering data received in a first clock domain and output in a second clock domain are also disclosed.

Integrated circuit for buffering data by removing idle blocks to create a modified data stream when memory device is not near empty

A programmable layered sub-system interface includes an extension sub-layer module, a physical coding sub-layer module, a physical media attachment module, an input module, an output module, a 1switch module and a 2switch module. The 1switch module is coupled between the physical media attachment module and the physical coding sub-layer module. The 2switch module is operably coupled between the physical coding sub-layer module and the extension sub-layer module. The input and output modules are operably coupled to the 1and 2switch modules. The 1switch module provides various combinations of coupling between the physical media attachment module, the physical coding sub-layer module, the input module and the output module. The 2switch module provides combinations of coupling between the extension sub-layer module, the physical coding sub-layer module, the input module and the output module.

Programmable layered sub-system interface

A method and apparatus for managing an optical transceiver includes processing that begins by transceiving management data with modules external to the optical transceiver. The processing then continues by converting the management data transceived with the external modules between a 1 data format (e.g., MDIO interface compatible) and a generic data format (e.g., a format convenient for reading data to and writing data from a random access memory). The processing continues by transceiving management data with modules internal to the optical transceiver. The processing continues by converting the management data transceived with the internal modules between the generic data format and a 2 data format (e.g., I C). The processing continues by arbitrating access to a shared memory, which stores the management data in the generic format, between requests from internal modules via the second controller and requests from external modules via the first controller.

Method and apparatus for managing an optical transceiver

An integrated circuit includes analog test cells to determine if an analog signal is within a predetermined voltage or current range. The test cell uses one or more analog reference signals to establish boundaries of a test range. Different embodiments of the analog test cells selectively test multiple analog signals provided in an integrated circuit. A test system can be provided to test multiple analog signals of an integrated circuit by scanning multiple analog test cells distributed throughout the integrated circuit and providing the test data for analysis. An analog circuit of an integrated circuit can be tested at different stages in manufacturing, including during a wafer stage prior to separation of individual circuit dice. Further, analog circuitry can be tested and characterized without the need for analog or digital/analog testers. In contrast, a digital only tester can be used to test analog circuitry.

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Austin, TX, United States of America

Justin Gaither