A data processor includes at least one power supply voltage terminal for receiving a power supply voltage and a power supply current, a data processing circuit, a register, and a port controller. The data processing circuit is coupled to the at least one power supply voltage terminal and operates using the power supply voltage. The register stores a nominal value of the power supply voltage, an electrical design current (EDC) limit, and an EDC slope, wherein the EDC slope specifies a desired voltage-current relationship for an external voltage regulator when the power supply current exceeds the EDC limit. The port controller is coupled to the register and to an output port. The data processing circuit is operative to cause the port controller to output the nominal value of the power supply voltage, the EDC limit, and the EDC slope over the output port for use by the external voltage regulator.

A time capture circuit can measure time between edges of a logic input signal. A delay line generates consecutive increasingly delayed replicas of the logic input signal. A free running counter is clocked by a counter clock signal corresponding to an external clock signal multiplied by a clock scale factor. A counter value capture circuit captures the counter value upon occurrence of an edge in the input signal, outputs a captured counter value, and issues a trigger signal. A decoder determines a decoded value based on values of the input signal and of the plurality of consecutive increasingly replicas when the trigger signal is issued and computes a capture value as the difference of the captured counter value logical left shifted by a first scale factor and the decoded value logical right shifted by a second scale factor.

A time capture circuit can measure time between edges of a logic input signal. A delay line generates consecutive increasingly delayed replicas of the logic input signal. A free running counter is clocked by a counter clock signal corresponding to an external clock signal multiplied by a clock scale factor. A counter value capture circuit captures the counter value upon occurrence of an edge in the input signal, outputs a captured counter value, and issues a trigger signal. A decoder determines a decoded value based on values of the input signal and of the plurality of consecutive increasingly replicas when the trigger signal is issued and computes a capture value as the difference of the captured counter value logical left shifted by a first scale factor and the decoded value logical right shifted by a second scale factor.

Equalization methods and equalizers employing discrete-time filters are provided with dynamic perturbation effect based adaptation. Tap coefficient values may be individually perturbed during the equalization process and the effects on residual ISI monitored to estimate gradient components or rows of a difference matrix. The gradient or difference matrix components may be assembled and filtered to obtain components suitable for calculating tap coefficient updates with reduced adaptation noise. The dynamic perturbation effect based updates may be interpolated with precalculated perturbation effect based updates to enable faster convergence with better accommodation of analog component performance changes attributable to variations in process, supply voltage, and temperature.

A crystal oscillator reducing phase noise and a semiconductor chip including the same are provided. The crystal oscillator includes a transconductance circuit electrically connected to a crystal, a load capacitor connected to the transconductance circuit, a feedback resistance circuit connected between an input terminal of the transconductance circuit and an output terminal of the transconductance circuit, the feedback resistance circuit configured to provide a feedback resistance, and a variable resistance controller configured to generate a resistance control signal for controlling the feedback resistance, the resistance control signal causing the feedback resistance to have a first value in a first period and a second value in a second period, the first value being less than the second value, the first period corresponding to a first portion of a cycle of the clock signal, and the second period corresponding to a second portion of the cycle different from the first portion.

A crystal oscillator reducing phase noise and a semiconductor chip including the same are provided. The crystal oscillator includes a transconductance circuit electrically connected to a crystal, a load capacitor connected to the transconductance circuit, a feedback resistance circuit connected between an input terminal of the transconductance circuit and an output terminal of the transconductance circuit, the feedback resistance circuit configured to provide a feedback resistance, and a variable resistance controller configured to generate a resistance control signal for controlling the feedback resistance, the resistance control signal causing the feedback resistance to have a first value in a first period and a second value in a second period, the first value being less than the second value, the first period corresponding to a first portion of a cycle of the clock signal, and the second period corresponding to a second portion of the cycle different from the first portion.

In a transmitter apparatus, a known reference signal is superimposed on top of a data signal that is typically not known a priori to a receiver and the combined signal is transmitted. At a receiver, an iterative channel estimation and equalization technique is used to recover the reference signal and the unknown data signal. In the initial iteration, the known reference signal is recovered by treating the data signal as noise. Subsequent iterations are used to improve estimation of received reference signal and the unknown data signal.

A data processor includes at least one power supply voltage terminal for receiving a power supply voltage and a power supply current, a data processing circuit, a register, and a port controller. The data processing circuit is coupled to the at least one power supply voltage terminal and operates using the power supply voltage. The register stores a nominal value of the power supply voltage, an electrical design current (EDC) limit, and an EDC slope, wherein the EDC slope specifies a desired voltage-current relationship for an external voltage regulator when the power supply current exceeds the EDC limit. The port controller is coupled to the register and to an output port. The data processing circuit is operative to cause the port controller to output the nominal value of the power supply voltage, the EDC limit, and the EDC slope over the output port for use by the external voltage regulator.

A data processor includes at least one power supply voltage terminal for receiving a power supply voltage and a power supply current, a data processing circuit, a register, and a port controller. The data processing circuit is coupled to the at least one power supply voltage terminal and operates using the power supply voltage. The register stores a nominal value of the power supply voltage, an electrical design current (EDC) limit, and an EDC slope, wherein the EDC slope specifies a desired voltage-current relationship for an external voltage regulator when the power supply current exceeds the EDC limit. The port controller is coupled to the register and to an output port. The data processing circuit is operative to cause the port controller to output the nominal value of the power supply voltage, the EDC limit, and the EDC slope over the output port for use by the external voltage regulator.

Pre-charging two or more sets of nodes to set a differential output of a multi-input summation latch connected to the two or more sets of nodes in a pre-charged state, the two or more sets of nodes comprising a set of data signal nodes and a set of DFE correction nodes, in response to a sampling clock, generating a differential data voltage and an aggregate differential DFE correction signal, and generating a data decision by driving the differential output of the multi-input summation latch into one of two possible output states according to a summation of the differential data voltage signal and the aggregate differential DFE correction signal and subsequently holding the data decision by holding the differential output of the multi-input summation latch in a latched state for a duration determined by the sampling clock.