Patent classifications
H04L7/0045
Clock and data recovery for pulse based multi-wire link
A method and an apparatus are provided. The apparatus may include a clock recovery circuit having a plurality of input latches configured to assume a first state when a first pulse is received in one or more of a plurality of input signals, combinational logic configured to provide a second pulse response to the first pulse, a delay circuit configured to produce a third pulse on a receive clock that is delayed with respect to the second pulse, a plurality of output flip-flops configured to capture the first state when triggered by the third pulse. The first state may identify which of the plurality of input signals received input pulses.
Methods and apparatus to reduce retimer latency and jitter
An example system includes: interleaving circuitry including a data input, a plurality of data outputs, and a plurality of clock inputs, the data input coupled to the received data input and each of the plurality of clock inputs coupled to one of the plurality of receiver clock outputs; and handoff circuitry coupled to the interleaving circuitry, the handoff circuitry including: comparison circuitry coupled to the clock generation circuitry and configured to compare the plurality of receiver clocks to the transmission clock; clock configuration circuitry coupled to the comparison circuitry and configured to select one of the plurality of receiver clocks based on the comparison circuitry; and a plurality of flip-flops coupled to the clock configuration circuitry and configured to convert the plurality of data outputs from the plurality of receiver clocks to the transmission clock to generate a plurality of transmission data streams based on the one of the plurality of receiver clocks selected by the clock configuration circuitry.
Mulit-lane synchronous reset for coherent receivers
A reset sub-circuit can sample the reset signal based on a low-speed clock reference signal to generate a series of sampled reset signals. A phase relation between a first selected one of the series of sampled reset signals and the high-speed clock signal at the clock input of each sampler can be measured to generate reset trigger signals corresponding to each of a plurality of samplers. A second selected one of the series of sampled reset signals can be sampled based on the high-speed clock signal to generate a positive sampled reset signal and a negative sampled reset signal. The reset sub-circuit can select between the positive sampled reset signal and the negative sampled reset signal based on the reset trigger signals corresponding to each sampler to generate the synchronous reset signal.
DUAL EDGE SYNCHRONIZATION OF ANALOG INPUT TO REDUCE SWITCH POINT JITTER
A method for synchronization of an input signal includes providing the input signal to a first signal path associated with a first clock and to a second signal path associated with a second clock, detecting an edge of the input signal by detecting values of the input signal along the first signal path at a first rising edge of the first clock and at a second rising edge of the first clock, detecting a value of the input signal along the second signal path at an edge of the second clock, and selecting the input signal from the first signal path or from the second signal path according to the detected value of the input signal along the second path when an edge of the input signal along the first path is detected.
ELECTRONIC DEVICE AND METHOD OF RECEIVING DATA
According to one embodiment, ao electronic device executes decision feedback-type equalization for input data using a tap coefficient while updating the tap coefficient. The electronic device includes a first memory cyclically receiving a tap coefficient, holing the tap coefficient received, and cyclically outputting the tap coefficient held, and a second memory receiving the tap coefficient cyclically output from the first memory and holding the tap coefficient received. The tap coefficient cyclically output from the first memory is delayed by at least one cycle than the tap coefficient cyclically received by the first memory. The tap coefficient held in the second memory is used for the decision feedback-type equalization in a no-signal period in which no input data exist.
SAMPLER WITH LOW INPUT KICKBACK
Methods and systems are described for receiving a signal to be sampled and responsively generating, at a pair of common nodes, a differential current representative of the received signal, receiving a plurality of sampling interval signals, each sampling interval signal received at a corresponding sampling phase of a plurality of sampling phases, for each sampling phase, pre-charging a corresponding pair of output nodes using a pre-charging FET pair receiving the sampling interval signal, forming a differential output voltage by discharging the corresponding pair of output nodes via a discharging FET pair connected to the pair of common nodes, the FET pair receiving the sampling interval signal and selectively enabling the differential current to discharge the corresponding pair of output nodes, and latching the differential output voltage.
Clock data recovery circuit
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 particular 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.
MULIT-LANE SYNCHRONOUS RESET FOR COHERENT RECEIVERS
A reset sub-circuit can sample the reset signal based on a low-speed clock reference signal to generate a series of sampled reset signals. A phase relation between a first selected one of the series of sampled reset signals and the high-speed clock signal at the clock input of each sampler can be measured to generate reset trigger signals corresponding to each of a plurality of samplers. A second selected one of the series of sampled reset signals can be sampled based on the high-speed clock signal to generate a positive sampled reset signal and a negative sampled reset signal. The reset sub-circuit can select between the positive sampled reset signal and the negative sampled reset signal based on the reset trigger signals corresponding to each sampler to generate the synchronous reset signal.
CLOCK AND DATA RECOVERY FOR PULSE BASED MULTI-WIRE LINK
A method and an apparatus are provided. The apparatus may include a clock recovery circuit having a plurality of input latches configured to assume a first state when a first pulse is received in one or more of a plurality of input signals, combinational logic configured to provide a second pulse response to the first pulse, a delay circuit configured to produce a third pulse on a receive clock that is delayed with respect to the second pulse, a plurality of output flip-flops configured to capture the first state when triggered by the third pulse. The first state may identify which of the plurality of input signals received input pulses.
Sampler with low input kickback
Methods and systems are described for receiving a signal to be sampled and responsively generating, at a pair of common nodes, a differential current representative of the received signal, receiving a plurality of sampling interval signals, each sampling interval signal received at a corresponding sampling phase of a plurality of sampling phases, for each sampling phase, pre-charging a corresponding pair of output nodes using a pre-charging FET pair receiving the sampling interval signal, forming a differential output voltage by discharging the corresponding pair of output nodes via a discharging FET pair connected to the pair of common nodes, the FET pair receiving the sampling interval signal and selectively enabling the differential current to discharge the corresponding pair of output nodes, and latching the differential output voltage.