Agere Systems Inc.

Lsi Corporation

Agere Systems Optoelectronics Guardian Corp.

Dwight David Daugherty

Xingdong Dai

Max Jay Olsen

Geoffrey Zhang

Lane Allen Smith

Mohammad Shafiul Mobin

Roger A Fratti

Gregory W Sheets

Johannes Gerardus Ransijn

Paul H Tracy

James D Yoder

Roger Anthony Fratti

John Wayne Bowen

Gary Schiessler

Peter Eyolf Bronner

Gregory C Salvador

Dennis Farley

Xiaohong Jiang

Kenneth D Gaynor

Techniques are disclosed for asynchronous calibration for eye diagram generation. For example, a method for calibrating a process for generating a data eye associated with a received signal comprises the following steps. Samples of the received signal are obtained for a first unit interval using a first data latch and a roaming latch. A delay offset is determined between the first data latch and the roaming latch by comparing at least one sample obtained using the first data latch and at least one sample obtained using the roaming latch, wherein the delay offset determined by the comparison is used to calibrate the process for generating the data eye associated with the received signal. A similar comparison may be done for a second data latch and used to calibrate the process. The method is able to find the accurate position of each data latch with respect to the roaming latch so as to improve the accuracy of data decoding in a digital receiver, i.e., provide receiver optimization.

Asynchronous calibration for eye diagram generation

Methods and apparatus are provided for joint adaptation of filter values in two communicating devices, such as a link partner and a link device. The disclosed joint adaptation process initially adapts the filter coefficient values in a first of the two communicating devices until a predefined stopping criteria is satisfied. Thereafter, the filter coefficient values in a second of the two communicating devices are adapted once the predefined stopping criteria for the first communicating device is satisfied. The filter coefficient values can comprise coefficient values of a multi-tap filter. The predefined stopping criteria may determine, for example, whether the first of the two communicating devices is overequalized. The filter coefficient values can be determined by including a contribution of only certain cursor tap values of the channel impulse response.

Methods and apparatus for joint adaptation of transmitter transversal filter in communication devices

A tracking/locating/paging system utilizes a 'pre-established' local area network to determine essentially real-time information regarding one or more client devices within a closed communication environment ('pre-established' also considered as including an ad hoc network connection of devices deployed to serve a common interest). Particularly suited for arrangements such as an amusement park, college campus, shopping mall, etc., the service of the present invention utilizes conventional client devices and includes the ability to transmit an identification signal unique to each device. Various network access points distributed through the closed environment receive these unique identification signals and can therefore pinpoint the location of various client devices in real time. Accordingly, a paging function may be added to further enhance the communication aspects of the tracking and locating features of the present invention.

Utilization of existing network infrastructure to provide person tracking capabilities

In described embodiments, automatic de-emphasis setting is provided for driving a capacitive backplane. Line impedance and line length of a transmission (TX) device are measured that form a load impedance of a driver. For some exemplary embodiments, the line impedance is predominantly a line capacitance, and such embodiments detect this capacitance. Measured line impedance is converted to a control signal (such as, for example, a three bit digital control signal) which automatically sets the de-emphasis of the TX stage. With the amount of capacitance and the length of the transmission line, the appropriate de-emphasis settings might be determined, and such de-emphasis setting be applied by the transmitter to the driver to compensate for transmission line effects.

Automatic de-emphasis setting for driving capacitive backplane

In described embodiments, an adaptive equalizer employed by a receiver in a communication channel, such as Fibre Channel, employs pattern recognition. When a repeating pattern, such as an IDLE or ARBFF pattern, is employed by a standard to, for example, maintain a communication link, an equalizer of the receiver might adaptively set its equalizer parameters based on characteristics of the signal energy of the repeating pattern rather than adaptively set its equalizer parameters based on characteristics of the signal energy of generally random user data carried on the link. Pattern recognition by the receiver allows for maintaining adaptive equalizer parameters at settings preferred for data detection of the typical random data, improving data detection performance of the receiver when the channel transitions from a preset or synchronization repeating pattern to a user random data pattern.

Adaptive equalization employing pattern recognition

In described embodiments, an adaptive equalizer employed by a receiver in a communication channel, such as Fiber Channel, employs pattern recognition. When a repeating pattern, such as an IDLE or ARBFF pattern, is employed by a standard to, for example, maintain a communication link, an equalizer of the receiver might adaptively set its equalizer parameters based on characteristics of the signal energy of the repeating pattern rather than adaptively set its equalizer parameters based on characteristics of the signal energy of generally random user data carried on the link. Pattern recognition by the receiver allows for maintaining adaptive equalizer parameters at settings preferred for data detection of the typical random data, improving data detection performance of the receiver when the channel transitions from a preset or synchronization repeating pattern to a user random data pattern.

Methods and apparatus are provided for data rate detection using a data eye monitor. The data rate is one of a plurality of data rates comprising a base rate and one or more divide-by-N multiples of the base rate, where N is an integer. The data rate of a received signal is detected by sampling the received signal; comparing the samples for a plurality of full rate data eyes associated with the received signal to determine if there is a mismatch between at least two predefined samples; and detecting the data rate by evaluating the comparison based on predefined criteria. The comparison can be performed by an exclusive or (XOR) logic gate for samples of at least two adjacent data eyes of a given rate.

Method and apparatus for data rate detection using a data eye monitor

A system and method are provided for providing an impedance match of an output buffer to a transmission line without significantly increasing the power consumption of the output buffer. A system and method are also provided for providing an impedance match of an output buffer to a transmission line, while still allowing for an adjustable output swing as is required for loads such as laser transmitters and optical modulators.

System and method for providing an impedance match of an output buffer to a transmission line

An apparatus which aligns a ball grid array (BGA) device over a substrate. The apparatus preferably includes a cup-shaped member for cupping and holding the solder balls of the BGA device, and an elongate member attached to the cup-shaped member. The cup-shaped member is attached between the BGA device and the substrate at two or more different positions so that the solder balls of the BGA device become aligned over the terminals of the substrate by operation of gravity.

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Ephrata, PA, United States of America

Dwight David Daugherty