International Business Machines Corporation

Benjamin D Parker

Arun Sridhar Natarajan

Mark Ferriss

Jose A Tierno

Alexander V Rylyakov

Soner Yaldiz

Alberto Valdes Garcia

Scott Kevin Reynolds

Herschel Akiba Ainspan

Mihai A Sanduleanu

Jean-Oliver Plouchart

Sameh W Asaad

Mohit Kapur

Charles Louis Haymes

Daniel Joseph Friedman

Sergey Vladimirovich Rylov

Mounir Meghelli

Albert X Widmer

Bernard V Brezzo

Ralph E Bellofatto

Azita Emami-Neyestanak

Thomas Roewer

Polarimetric transceiver front-ends and polarimetric phased array transceivers include two receive paths configured to receive signals from an antenna, each including a respective variable phase shifter. A first transmit path is connected to the variable phase shifter of one of the two receive paths and is configured to send signals to the antenna. A transmit/receive switch is configured to select between the first transmit path and the two receive paths for signals. The transmit/receive switch has an element that adds a high impedance to the transmit path when the transmit/receive switch is in a receiving state.

Scalable polarimetric phased array transceiver

A polarimetric transceiver front-end includes two receive paths configured to receive signals from an antenna, each receive path corresponding to a respective polarization. Each front-end includes a variable amplifier and a variable phase shifter; a first transmit path configured to send signals to the antenna, where the transmit path is connected to the variable phase shifter of one of the two receive paths and includes a variable amplifier; and a transmit/receive switch configured to select between the first transmit path and the two receive paths for signals, where the transmit/receive switch includes a quarter-wavelength transmission line that adds a high impedance to the transmit path when the transmit/receive switch is in a receiving state.

A method and system are disclosed for measuring a specified parameter in a phase-locked loop frequency synthesizer (PLL). In one embodiment, the method comprises introducing multiple phase errors in the PLL, measuring a specified aspect of the introduced phase errors, and determining a value for the specified parameter using the measured aspects of the introduced phase errors. In one embodiment, the phase errors are introduced repetitively in the PLL, and these phase errors produce a modified phase difference between the reference signal and the feedback signal in the PPL. In one embodiment, crossover times, when this modified phase difference crosses over a preset value, are determined, and these crossover times are used to determine the value for the specified parameter. In an embodiment, the parameter is calculated as a mathematical function of the crossover times. The parameter may be, for example, the bandwidth of the PLL.

Loop parameter sensor using repetitive phase errors

First and second field programmable gate arrays are provided which implement first and second blocks of a circuit design to be simulated. The field programmable gate arrays are operated at a first clock frequency and a wire like link is provided to send a plurality of signals between them. The wire like link includes a serializer, on the first field programmable gate array, to serialize the plurality of signals; a deserializer on the second field programmable gate array, to deserialize the plurality of signals; and a connection between the serializer and the deserializer. The serializer and the deserializer are operated at a second clock frequency, greater than the first clock frequency, and the second clock frequency is selected such that latency of transmission and reception of the plurality of signals is less than the period corresponding to the first clock frequency.

Wire like link for cycle reproducible and cycle accurate hardware accelerator

A plurality of target field programmable gate arrays are interconnected in accordance with a connection topology and map portions of a target system. A control module is coupled to the plurality of target field programmable gate arrays. A balanced clock distribution network is configured to distribute a reference clock signal, and a balanced reset distribution network is coupled to the control module and configured to distribute a reset signal to the plurality of target field programmable gate arrays. The control module and the balanced reset distribution network are cooperatively configured to initiate and control a simulation of the target system with the plurality of target field programmable gate arrays. A plurality of local clock control state machines reside in the target field programmable gate arrays. The local clock control state machines are coupled to the balanced clock distribution network and obtain the reference clock signal therefrom. The plurality of local clock control state machines are configured to generate a set of synchronized free-running and stoppable clocks to maintain cycle-accurate and cycle-reproducible execution of the simulation of the target system. A method is also provided.

Method and infrastructure for cycle-reproducible simulation on large scale digital circuits on a coordinated set of field-programmable gate arrays (FPGAs)

A method and system for compensating for offsets when measuring parameters of a phase-locked loop (PLL). In one embodiment, a proportional path in the PLL is temporarily shut off, a measurement is made of a real time-to-zero crossing in the PLL to measure a defined parameter of the PLL, the proportional path is switched on, and the defined loop parameter is adjusted based on this measurement. In one embodiment, the real time-to-zero crossing is measured after introducing a phase step into the PLL between a reference signal and an output signal of the PLL. In an embodiment, two phase steps, having opposite polarities, are successively introduced into the PLL, and the time-to-crossing measurements resulting from these two phase steps may be averaged, and this average is used to determine a loop parameter.

PLL bandwidth correction with offset compensation

Clock synchronization and data recovery techniques are disclosed. For example, a technique for synchronizing a clock for use in recovering received data comprises the following steps/operations. A first clock (e.g., a data clock) is set for a first sampling cycle to a first phase position within a given unit interval in the received data. A second clock (e.g., a sweep clock) is swept through other phase positions with respect to the first phase position such that a transition from the given unit interval to another unit interval in the received data is determined. A sampling point is determined based on measurements at the phase positions associated with the second clock. The second clock is set to the phase position corresponding to the sampling point such that data may be recovered at that sampling point. Further, for a next sampling cycle, the first clock may be used to sweep through phase positions with respect to the set phase position of the second clock corresponding to the sampling point in the first sampling cycle such that a next sampling point may be determined.

Methods and apparatus for clock synchronization and data recovery in a receiver

Phase selection mechanisms for the optimal sampling of data at the receiving end of a SSC interface. The receiver is allowed to choose between several phases of its local clock, to best synchronize the transmitter data to the receiver clock domain. It results in a minimum depth first in first out (FIFO) register to accomplish the handoff of transmit data from the transmit clock to the receive dock. It avoids the requirement of a delay locked loop (DLL) to bring the transmitter clock into a desired phase relationship with respect to the receiver clock. At least one embodiment of the present invention provides a solution specific to the DDR or full rate clocking SSC interface.

Phase selection mechanism for optimal sampling of source synchronous clocking interface data

A format converter in which the data input is a 16 bit wide interface. The circuit finds the 66-bit coding block boundaries. In one embodiment, a circuit presents the 66-bit data blocks at the output in an aligned format. The circuit relies on control inputs from a state machine which controls the operating mode and to which it delivers status information. The two main operating modes are the &ldquo;normal data&rdquo; mode or the &ldquo;hunt&rdquo; mode for the 66-bit block boundaries.

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Peekskill, NY, United States of America

Benjamin D Parker