A example receiver includes analog circuitry configured to equalize and amplify an input signal and provide an analog signal as output; clock data recovery (CDR) circuitry configured to recover data clocks and edge clocks from the analog signal; a plurality of eye height optimization circuits, each of the plurality of eye height optimization circuits configured to, based on a respective data pattern of a plurality of data patterns, sample the analog signal based on the data clocks and the edge clocks, feed back first information to the analog circuitry for adjusting the eye amplitude, and feed back second information to the CDR circuitry for adjusting the data clocks; and an eye width optimization circuit configured to receive data and edge samples from the plurality of eye height optimization circuits, feed back third information to the CDR circuitry to adjust the edge clocks, and feed back fourth information to the analog circuitry to adjust the equalization.

A data transmission device of an embodiment includes a buffer, a first determination circuit, a first flip-flop, a second flip-flop, and a second determination circuit. The buffer holds input data of a predetermined bit width. The first determination circuit determines whether or not the input data is held in the buffer. The first flip-flop receives output of the first determination circuit as input and operates at one of a rising edge and a falling edge of a second clock signal which is asynchronous with the first clock signal. The second flip-flop receives output of the first flip-flop as input and operates at another of the rising edge and the falling edge of the second clock signal. The second determination circuit determines an error based on a request signal which is synchronized with the second clock signal and output of the second flip-flop.

A clock data recovery circuit includes a deglitch filter circuit and a timer circuit. The deglitch filter circuit is configured to remove pulses of less than a predetermined duration from a data signal to produce a deglitched data signal. The timer circuit is coupled to the deglitch filter, and is configured to compare a duration of a pulse of the deglitched data signal to a threshold duration, and identify the pulse as representing a logic one based on the duration of the pulse exceeding the threshold duration.

A semiconductor device outputs, as an output signal synchronized to a phase-locked loop clock signal, a synchronized input signal that is synchronized to a reference clock signal of a phase-locked loop circuit. The semiconductor device includes the phase-locked loop circuit, a first flip-flop that receives the input signal in synchronization with the reference clock signal on the basis of a feedback signal inputted to a phase comparator of the phase-locked loop circuit 10, and a second flip-flop that receives an output from the first flip-flop on the basis of the phase-locked loop clock signal. The second flip-flop outputs the output from the first flip-flop as the output signal. A setup time to synchronize the input signal to the phase-locked loop clock signal is set to one half of a period of the reference clock signal.

A signal receiver includes a first preliminary receiver circuit suitable for receiving an input signal and generating a first preliminary reception signal based on a first reference voltage, a second preliminary receiver circuit suitable for receiving the input signal and generating a second preliminary reception signal based on a second reference voltage, a reception circuit suitable for selecting one of the first preliminary reception signal and the second preliminary reception signal in response to a voltage level of a reception signal and generating the reception signal using the selected signal, and a reference voltage generation circuit suitable for adjusting a voltage level of the first reference voltage based on a first offset and adjusting a voltage level of the second reference voltage based on a second offset.

A data synchronizer including an input stage, a driver stage, and a keeper stage. The input stage latches input data to a data node in response to a first clock signal transition. The driver stage has an input coupled to the data node and has an output coupled to a gain node. The keeper stage latches data asserted on the gain node back to the input stage to maintain data on the data node in response to a second transition of the clock signal. The driver stage has an increased drive strength and a reduced loading capacitance to increase the gain-bandwidth product of the latch loop to reduce metastability. A flip-flop may be configured with input and output latches each including driver stages having increased drive strength and reduced loading capacitance to increase the gain-bandwidth product of each of the latch loops to reduce metastability.

A data transmission device of an embodiment includes a buffer, a first determination circuit, a first flip-flop, a second flip-flop, and a second determination circuit. The buffer holds input data of a predetermined bit width. The first determination circuit determines whether or not the input data is held in the buffer. The first flip-flop receives output of the first determination circuit as input and operates at one of a rising edge and a falling edge of a second clock signal which is asynchronous with the first clock signal. The second flip-flop receives output of the first flip-flop as input and operates at another of the rising edge and the falling edge of the second clock signal. The second determination circuit determines an error based on a request signal which is synchronized with the second clock signal and output of the second flip-flop.

A signal transmitting circuit providing compatibility and stability in signal transmissions across domains with different clock frequencies includes an edge detection circuit, a flip circuit, a synchronization circuit, and an edge extraction circuit. The edge detection circuit detects an edge of an initial interrupt signal and generates an event trigger signal in a faster clock domain. The flip circuit converts the event trigger signal into an edge signal. The synchronization circuit synchronizes the edge signal under a slower clock domain and generates a synchronization signal. The edge extraction circuit generates a trigger signal based on the synchronization signal in the slower clock domain to a target circuit in the slower clock domain. A method and an electronic apparatus related to the signal transmitting circuit are also disclosed.

A data synchronization unit including first flip-flops, operating on a first clock domain and a reset of a second clock domain, sampling data from the first clock domain; a second flip-flop, operating in the first clock domain, sampling a request signal when enabled by a request pulse; a request signal path configured to delay the request signal by a first delay and to generate an enable signal for recirculation multiplexers in accordance with the delayed request signal; a reset signal synchronization path configured to delay the reset signal of the first clock domain by a second delay, wherein the second delay is shorter than the first delay; and multiplexers having first inputs for receiving outputs of the recirculation multiplexers, a second input for receiving a reset value of a programmable register, the multiplexers being configured to selectively output signals at inputs to outputs.

A clock data recovery circuit includes a deglitch filter circuit and a timer circuit. The deglitch filter circuit is configured to remove pulses of less than a predetermined duration from a data signal to produce a deglitched data signal. The timer circuit is coupled to the deglitch filter, and is configured to compare a duration of a pulse of the deglitched data signal to a threshold duration, and identify the pulse as representing a logic one based on the duration of the pulse exceeding the threshold duration.