Cadence Design Systems, Inc.

International Business Machines Corporation

Koninklijke Philips Corporation N.v.

Loren Blair Reiss

Edward Hau-chun Ku

Joseph M Rash

Scott David Huss

Douglas Ray Henderson

Brian Mitchell Bass

Thomas Eric Ryle

Jim Philip Ervin

Dennis Albert Doidge

Scott J Lemke

Fred Staples Stivers

Bonnie Collett Sexton

Pramod Narottambhai Patel

Christopher George Moscone

D Adam Shiel

James Dennis Vandersand, Jr

Charles Steven Lingafelt

Eric Harris Naviasky

Joseph Kinman Lee

Benjamin Louis Heilmann

Steven Martin Broome

Chris Moscone

Jeffrey Wayne Kidd

Karen Park Heron

Matthew Robert Collin

Randall Smith

James Lee House

Ramakrishna Kasukurthi

R Christopher Noonan

Scott Gerald Bare

Kelvin E McCollough

Various embodiments provide for testing a transmitter with interpolation, which can be used with a circuit for data communications, such as serializer/deserializer (SerDes) communications. In particular, some embodiments provide for data transmission test of a transmitter by: generating and outputting a pre-determined data pattern through a serializer of the transmitter; sampling a serialized data output of the serializer over a plurality of different interpolation phase positions of a phase interpolator; and using a pattern checker to error check the sampled data over the plurality of different interpolation phase positions to determine whether the data transmission test passes.

Transmitter test with interpolation

Various embodiments provide for calibrating one or more clock signals for a serializer, which can be used with a circuit for data communications, such as serializer/deserializer (SerDes) communications. In particular, for a serializer operating based on a plurality of clock signals, some embodiments provide for calibration of one or more of the plurality of clock signals by adjusting a duty cycle of one or more clock signals, a delay of one or more clock signals, or both.

Clock calibration for data serializer

A physical layer (PHY) device comprises a phase interpolator to generate a set of sampler clocks. A sampler of the PHY device samples a calibration data pattern based on the set of sampler clocks. A data alignment system of the PHY device performs a coarse calibration and a fine calibration on the sampler clock signals. During the coarse calibration, the data alignment system moves the sampler clock signals earlier or later in time relative to the sampled data based on a first bit of the sampled data. During the fine calibration, the data alignment system moves the sampler clock signals earlier or later in time relative to the sampled data based on the first bit, a second bit, and a third bit in the sampled data.

Data alignment in physical layer device

A phase interpolator of a physical layer (PHY) device comprise a phase interpolator to generate a set of asynchronous sampler clocks. A sampler of the PHY device samples a calibration data pattern using a first sampler clock from the set of asynchronous sampler clocks. A calibration control component of the PHY device detects a misalignment of a phase relationship among the set of asynchronous sampler clocks based on the sampled data. In response to detecting the misalignment, the calibration control component calibrates the first sampler clock using a second sampler clock and a third sampler clock.

Static clock calibration in physical layer device

Various embodiments provide for phase interpolators with phase adjusters to provide step resolution, which can be used with a circuit such as a data serializer/deserializer circuit. In particular, for some embodiments, a phase interpolator is coupled to a phase adjuster, where the combination of the phase interpolator and the phase adjuster is configured to interpolate between phases in phase adjustment steps at a phase adjustment step resolution. For such embodiments, the phase adjustment step resolution of the steps is achieved by controlling the phase interpolator and the phase adjuster.

Phase interpolator with phase adjuster for step resolution

A calibration control component within a transmit (TX) or receive (RX) device executes a calibration sequence to ensure reliable data transmission and reception within the device. The calibration sequence comprises a set of calibration functions that are sequentially executed. The calibration control component detects a pause function being enabled based on a pause function configuration register. Based on detecting the pause function being enabled, the calibration control component pauses execution of the calibration sequence.

Pause control for a calibration sequence

A set of encoders within a transmitter (TX) physical layer (PHY) encode incoming data using a predefined encoder scheme by translating multiple data segments into a set of balanced bit sequences. Each data segment comprises a first number of bits and each balanced bit sequence comprises a second number of bits. A data striping component distributes the set of balanced bit sequences to a set of serializers by routing bits from particular bit positions in each balanced bit sequence to a corresponding serializer. The set of serializers generates serialized data based on the set of balanced bit sequences.

Encoding and striping technique for DC balancing in single-ended signaling

Systems and methods disclosed herein provide for preventing the mis-equalization of signals transmitted over short transmission channels. Embodiments of the systems and methods provide for a receiver including a digital receiver equalization circuit that selectively provides a correction signal to a DFE tap weight based on the value of the current DFE tap weight as well as the logical values of the in-phase and error data samples associated with received signal.

Method for preventing mis-equalizations in decision feedback equalizer based receivers for low loss channels

A circuit and method for adaptively controlling an equalizer circuit to reduce intersymbol interference at low frequencies relative to a transmit frequency of an input signal from a transmitter. The input signal is converted into a data signal by a receiver. At least one delayed data signal is formed by delaying the data signal by at least one unit interval (UI) beyond a length of a decision feedback equalizer (DFE) in the receiver. An error signal is formed by comparing the input signal to a threshold value. An error signal sample is correlated with at least one delayed data signal sample to determine whether to adjust a control coefficient of the equalizer. Thus the equalizer is controlled as if the DFE had at least one additional tap.

Method of adaptively controlling a low frequency equalizer

The present disclosure relates to a method for use with a serializer/deserializer comprising. The method may include operatively connecting one or more lane modules of an integrated circuit (IC) to form one or more links. The method may further include associating a FIFO reset generator with each of the one or more lane modules and receiving a signal from the FIFO reset generator at a synchronization FIFO. The method may also include aligning, at the synchronization FIFO, one or more enqueue pointers and dequeue pointers.

SerDes alignment process

The present disclosure relates to a method for use with a serializer/deserializer comprising. The method may include grouping one or more lane modules associated with an integrated circuit (IC) together to form a link, wherein each of the one or more lane modules includes a reset state machine and a high speed reset generator. The method may also include providing a common module having a common reset release state machine and a reset release synchronizer and pulse generator, the common module and one or more lane modules being configured to communicate therebetween. The method may further include resetting each link independently using the one or more lane modules.

Method for link resets in a SerDes system

A multiported LAN switch comprised of legacy local area network ports and ATM ports. Each ATM port comprising a hardware forwarding engine for bridging LAN frames from the LAN ports to the ATM port. The hardware forwarding engine converts layerprotocols between the dissimilar ports expediently, without requiring intervention by a microprocessor. A substantial performance gain is attained compared to microprocessor controlled format converters. Both LAN emulation and virtual LANs are supported.

Method and apparatus for hardware forwarding of LAN frames over ATM networks

A multiported LAN switch comprised of legacy local area network ports and ATM ports. Each ATM port comprising a hardware forwarding engine for bridging LAN frames from the LAN ports to the ATM port. The hardware forwarding engine converts layer 2 protocols between the dissimilar ports expediently, without requiring intervention by a microprocessor. A substantial performance gain is attained compared to microprocessor controlled format converters. Both LAN emulation and virtual LANs are supported.

A circuit arrangement and method facilitate the execution of switch instructions such as Java lookupswitch and tableswitch instructions in hardware through emulation of such instructions using a plurality of conditional branch instructions from the same instruction set as the switch instructions, and which are capable of being directly implemented in hardware. The conditional branch instructions are typically generated by switch instruction handling logic and passed to execution logic capable of natively executing the conditional branch instructions. By emulating a complex switch instruction in switch instruction handling logic using a plurality of conditional branch instructions from the same instruction set, often the amount of custom circuitry needed to fully support a complex switch instruction is substantially reduced from what would be required to natively support the switch instruction in the execution logic of a hardware processor. Moreover, compared to software emulation, which typically requires passing control to a software interpreter, the overhead associated with emulating a switch instruction in the instruction fetch logic using multiple conditional branch instructions capable of being natively executed by execution logic offers substantial gains in performance.

Growing community of inventors

Raleigh, NC, United States of America

Loren Blair Reiss