Processing a digital bit stream and systems for implementing the methods are provided. The method includes dividing the digital bit stream into a plurality of data packets. In a first processing block performing a carrier recovery error calculation on a first portion of the plurality of data packets, comprising preforming a first phase locked loop (PLL) function on decimated data of the data packets and performing a carrier recovery operation on the first portion of the plurality of data packets. In a second processing block, in parallel with the processing of the first portion of the plurality of packets, performing the carrier recovery error calculation on a second portion of the plurality of data packets, comprising preforming the first PLL function on decimated data of the data packets and performing the carrier recovery operation on second portion of the plurality of data packets.

Apparatus and methods are provide for a multichannel clock and data recovery (CDR) device that shares information between channels. In an example, a multiple channel communication circuit can include a plurality of clock and data recovery (CDR) circuits, each CDR circuit of the plurality of CDR circuits associated with a channel of the multiple channel communication circuit. In certain examples, each CDR circuit can be configured to detect an incoming stream of data from the channel, to determine a setting of one or more parameters for correctly sampling the data from the incoming stream, and to share an indication of the setting of the one or more parameters to an adjacent CDR circuit of the plurality of CDR circuits.

A circuit for performing clock recovery according to a received digital signal. The circuit includes at least an edge sampler and a data sampler for sampling the digital signal, and a clock signal supply circuit. The clock signal supply circuit provides edge clock and data clock signals offset in phase from one another to the respective clock inputs of the edge sampler and the data sampler. A digital phase detector determines if the data clock is early, late or synchronized with respect to data value transitions in the digital signal, and based on that determination provides a phase adjustment signal to the clock signal supply circuit, which is operable to vary phases of the data and edge clock signals accordingly.

This application presents an adaptive data recovery from distorted signals (ADRDS) of original data symbols from intervals or parameters of tone signals derived from a received OFDM signal, including responding to dynamic distortions introduced to the received OFDM signal by an OFDM transmission channel. Such ADRDS is implemented by converting back the derived intervals or parameters into original data symbols corresponding to distinctive sets of the intervals or parameters which the derived intervals or parameters belong to.

Embodiments of circuits for use with an amplifier that includes multiple amplifier paths include a first circuit and a second circuit in parallel with the first circuit. The first circuit includes a first input coupled to a first power divider output, a first output coupled to a first amplifier path of the multiple amplifier paths, and a first adjustable phase shifter and a first attenuator series coupled between the first input and the first output. The second circuit includes a second input coupled to a second power divider output, a second output coupled to a second amplifier path of the multiple amplifier paths, and a second adjustable phase shifter coupled between the second input and the second output.

An integrated circuit includes a plurality of receivers, each having a clock and data recovery circuit. A first local clock recovery circuit in a first receiver can be caused to produce a test clock which simulates a condition to be tested, and while a second receiver in the plurality of receivers that includes a second local clock recovery circuit is caused to use the test clock in place of the reference clock while receiving a test data sequence at its input. The clock and data recovery circuits in the receivers can include clock control loops responsive to loop control signals to modify the selected reference clock to generate the local clock in response to selective one of (i) a corresponding data signal for normal operation or during a test, and (ii) a test signal applied to the clock control loop in which case the test clock is produced.

Phase synthesis techniques (PST) useful in a wide variety of communication systems based on wireless, optical and wireline links, disclose methods and circuits for a programmable synthesis of a waveform from a referencing clock with phase resolution matching a single gate delay.

An oscillation circuit includes: an oscillator configured to generate N phase clocks (where N is an integer of 2 or more) including a first phase clock to Nth phase clock whose phases are shifted by 360/N at regular intervals; a pulse generating part configured to receive a plurality of the N phase clocks and generate a plurality of intermediate pulses each having a duty ratio of 25%; and a clock synthesizing part configured to synthesize the plurality of intermediate pulses to generate a single phase output clock or multi-phase output clocks, the single phase output clock and the multi-phase output clocks having a frequency that is twice an oscillation frequency of the oscillator.

The present invention relates to the field of optical module, and provides a high-speed optical module for an optical fiber channel. The optical module can be used for 16G optical fiber channel, and comprises parts for emitting, receiving, clock data recovery and controlling. The optical module can be downward compatible with the application of 8G optical fiber channel and 4G optical fiber channel, support the diagnostic tests on optical circuit loopback and electrical circuit loopback, and provide stable receiving alarming. The optical module of the present invention, when serving as the interface between optical fiber channel systems and the interface between optical storage network storage devices, has the characteristics of miniaturization and low power consumption, and can improve port application density; the module supports hot swapping, which facilities the field debugging of the system, and can realize the replacing of the optical module without power down; and the module supports a digital diagnostic interface, and the network administrator can monitor the working state of the optical module by using the communication interface.

A CDR circuit includes: a comparison circuit that receives data signal on which a first clock signal is superimposed, and outputs a comparison result obtained by comparing the data signal with three different threshold values at a timing synchronized with a second clock signal; a data pattern detection circuit that detects an occurrence of a data pattern, based on the comparison result; a frequency detection circuit that outputs, when an occurrence of the data pattern is detected, a detection result indicating whether a second frequency of the second clock signal is higher than a first frequency of the first clock signal; an adjustment circuit that outputs, based on the detection result, an adjustment signal for adjusting a phase of the second clock signal and the second frequency; and an oscillator circuit that outputs the second clock signal with the phase and the second frequency adjusted, based on the adjustment signal.