Broadcom Corporation

David Kyong-Sik Chung

Afshin Momtaz

Mario Caresosa

Thomas J Kolze

Bruce Joseph Currivan

Guangming Yin

Ichiro Fujimori

Davide Tonietto

Pang-Cheng Hsu

An equalization circuit adjusts (e.g., equalizes) an input signal according to the value of one or more adjustment signals (e.g., equalization coefficients) without a multiplication operation. For example, the circuit may add or subtract a value of a coefficient signal to the amplitude of an input signal. Here, whether the coefficient is added or subtracted may depend on the sign of a control signal.

Decision feedback equalizer circuit

Various example embodiments are disclosed. According to an example embodiment, an apparatus may include a continuous time filter, a decision feedback equalizer, a clock and data recovery circuit, and an adaptation circuit. The adaptation circuit may be configured to adapt equalization according to at least one dithering algorithm by adjusting a delay adjust signal based on a mean square error of equalized data signals.

High speed receive equalizer architecture

Phase locked loops that can adjust the frequency of a clock signal are provided. A transmitter adjusts its data transmission rate in response to the clock signal to accommodate different data transmission protocols. A phase locked loop can add or drop cycles from an input clock signal in response to one or more signals from a receiver. The signals from the receiver indicate the transmission rate of the incoming data signal. The phase locked loop can drop cycles from the clock signal to decrease the frequency of the clock signal. The transmitter then decreases its data transmission rate in response to the reduced frequency of the clock signal. The phase locked loop can also add cycles to the clock signal to increase the frequency of the clock signal. The transmitter increases its data transmission rate in response to the increased frequency of the clock signal.

Phase lock loop with cycle drop and add circuitry

A compensation apparatus maintains an effective resistance of one or more resistors in a circuit by associating an adjustable resistor circuit to each resistor. The compensation apparatus compares the resistance of a resistor in the circuit with the resistance of a reference resistor. When the resistance of the resistor in the circuit falls outside of a desired range, the compensation apparatus adjusts the resistance of the adjustable resistor to adjust the effective resistance of the resistor and adjustable resistor combination.

Resistor compensation apparatus

A lock-detect circuit is configured to detect whether an incoming signal has acquired a lock to a reference signal using a first frequency detect window and to detect whether the incoming signal has lost a previously acquired a lock to the reference signal using a second frequency detect window different from the first frequency detect window. The two signals are applied to two different down-counters that are first synchronized before initiating the count-downs. If the offset between the counts of the two counters is less than the first frequency detect window, the incoming signal is detected as having acquired a lock to the reference signal. If the offset between the counts of the two counters is greater than the second frequency detect window, the incoming signal is detected as having lost its previously acquired lock to the reference signal.

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Irvine, CA, United States of America

David Kyong-Sik Chung