H04L25/49

Sampler reference level, DC offset, and AFE gain adaptation for PAM-N receiver
10728063 · 2020-07-28 · ·

In a PAM-N receiver, sampler reference levels, DC offset and AFE gain may be jointly adapted to achieve optimal or near-optimal boundaries for the symbol decisions of the PAM-N signal. For reference level adaptation, the hamming distances between two consecutive data samples and their in-between edge sample are evaluated. Reference levels for symbol decisions are adjusted accordingly such that on a data transition, an edge sample has on average, equal hamming distance to its adjacent data samples. DC offset may be compensated to ensure detectable data transitions for reference level adaptation. AFE gains may be jointly adapted with sampler reference levels such that the difference between a reference level and a pre-determined target voltage is minimized.

Interface circuit

A method for a bus interface circuit is described. According to one exemplary embodiment, the method comprises coding a first data stream by assigning first symbols to falling and rising edges of the first data stream, and coding a further data stream by assigning second symbols to the edges or levels of said further data stream. A symbol sequence is constructed from the first symbols and second symbols, wherein said symbol sequence is constructed in such a manner that the first symbols are always delayed by the same value relative to the associated edges of the first data stream. The method also comprises transmitting the symbol sequence via a galvanically isolating component, and decoding the symbol sequence transmitted via the galvanically isolating component in order to reconstruct the first data stream and the further data stream.

CHIP FAILURE DETECTION METHOD AND DEVICE
20200235964 · 2020-07-23 ·

Embodiments herein provide a method for detecting a failure of a chip. The method includes dividing a plurality of channels of the chip into multiple channel groups, providing an input bit stream to each channel group of the multiple channel groups and monitoring whether there is a difference between an output bit stream of each channel in the channel group and the input bit stream, and determining based on the difference whether each of the multiple channel groups is an abnormal channel group. Input bit streams provided to respective channels in a same channel group are identical.

SELF REFERENCED SINGLE-ENDED CHIP TO CHIP COMMUNICATION

A system and method for efficiently transporting data in a computing system are contemplated. In various embodiments, a computing system includes a source, a destination and multiple lanes between them for transporting data. Multiple receivers in the destination has a respective termination resistor connected to a single integrating capacitor, which provides a reference voltage to the multiple receivers. The receivers reconstruct the received data by comparing the corresponding input signals to the reference voltage. The source includes a table storing code words. The source maps a generated data word to a code word, which is sent to the destination. The destination maps the received code word to the data word. The values of the code words are selected to maintain a nearly same number of Boolean ones on the multiple lanes over time as a number of Boolean zeroes.

HIGH SPEED COMMUNICATIONS SYSTEM
20200235963 · 2020-07-23 ·

Transmission of baseband and carrier-modulated vector codewords, using a plurality of encoders, each encoder configured to receive information bits and to generate a set of baseband-encoded symbols representing a vector codeword; one or more modulation circuits, each modulation circuit configured to operate on a corresponding set of baseband-encoded symbols, and using a respective unique carrier frequency, to generate a set of carrier-modulated encoded symbols; and, a summation circuit configured to generate a set of wire-specific outputs, each wire-specific output representing a sum of respective symbols of the carrier-modulated encoded symbols and at least one set of baseband-encoded symbols.

HIGH SPEED COMMUNICATIONS SYSTEM
20200235963 · 2020-07-23 ·

Transmission of baseband and carrier-modulated vector codewords, using a plurality of encoders, each encoder configured to receive information bits and to generate a set of baseband-encoded symbols representing a vector codeword; one or more modulation circuits, each modulation circuit configured to operate on a corresponding set of baseband-encoded symbols, and using a respective unique carrier frequency, to generate a set of carrier-modulated encoded symbols; and, a summation circuit configured to generate a set of wire-specific outputs, each wire-specific output representing a sum of respective symbols of the carrier-modulated encoded symbols and at least one set of baseband-encoded symbols.

BURST ERROR ADDITION DEVICE, TEST SIGNAL GENERATION DEVICE USING SAME, AND BURST ERROR ADDITION METHOD
20200235828 · 2020-07-23 ·

There are included an error signal generation unit that generates an error signal for adding a burst error to each of an MSB and an LSB of the PAM4 signal in units of clock cycles, an error addition unit that performs an exclusive OR operation on the MSB and the LSB and the error signal and outputs bit strings obtained as a result of the operation, and a calculation unit that calculates the minimum number of clock cycles required for realizing a bit error rate of a desired test signal and the number of burst errors to be added to the MSB and the LSB during a period of the minimum number of the clock cycles.

BUS DECODE AND TRIGGERING ON DIGITAL DOWN CONVERTED DATA IN A TEST AND MEASUREMENT INSTRUMENT
20200233827 · 2020-07-23 ·

A test and measurement instrument including a digital down converter configured to receive a bus signal and output in-phase and quadrature-phase baseband component waveform data, a trace generator configured to receive the in-phase and quadrature-phase baseband component waveform data and generate at least one radio frequency versus time trace, a decoder configured to receive the at least one radio frequency versus time trace and decode the bus signal based on the at least one radio frequency versus time trace and a wireless modulation scheme, and a trigger configured to capture at least a portion of the bus signal based on the decoded bus signal.

PAM-4 transmitter precoder for 1+0.5D PR channels

A system and method for a high-speed transmitter comprising a precoder configured to receive a sequence of input symbols and to generate for each received symbol a respective recoded symbol is disclosed. The transmitter includes a recoding unit configured for recoding each current received PAM-M based on the recoded symbol immediately preceding the current recoded symbol at the recoding unit, a shift unit configured for determining a shift value for each current received symbol from the recoding unit based on the symbol received from the recoding unit and immediately preceding the current symbol at the shift unit; and Feed-Forward Equalizer unit for applying the shift values to the respective symbols received from the recoding unit to generate a corresponding sequence of output symbols to be transmitted in an output stream.

Unequal spacing on multilevel signals

The present disclosure provides signal management with unequal eye spacing by: sending, from a local transmitter, first and second signals with different first and second known eye patterns to a remote receiver over a channel; sending temperature data of the local transmitter and operating wavelength data of the first and second signals to the remote receiver over the channel; receiving, from the remote receiver, tuning parameters based on a dispersion of the channel based on a first difference between the first known eye pattern as transmitted and as received and a second difference between the second known eye pattern as transmitted and as received; and adjusting transmission rail values used to encode data for transmission over the channel by the local transmitter based on the tuning parameters to produce a conditioned signal for transmission with an unequally spaced eye pattern.