US-12627325-B2 - Receiver performing adaptive calibration

US12627325B2US 12627325 B2US12627325 B2US 12627325B2US-12627325-B2

Abstract

A receiver includes a channel compensator, a decoder and an adaptive controller. The channel compensator performs channel compensation on an input data signal to generates a feed-in data signal. The decoder demultiplexes a to-be-decoded data signal that originates from the feed-in data signal into multiple demultiplexed data signals, and decoding the demultiplexed data signals respectively into multiple decoded signals. Based on a decoded output that originates from the decoded signals, the adaptive controller performs adaptive calibration on the channel compensator to adjust a gain of the channel compensator with reference to an error portion of a first sample of the decoded signals and a data portion of a second sample of the decoded signals that is generated before the generation of the first sample of the decoded signals.

Inventors

Pen-Jui Peng
Yen-Po Lin

Assignees

NATIONAL TSING HUA UNIVERSITY

Dates

Publication Date: 20260512
Application Date: 20230620

Claims (16)

1 . A receiver comprising: a channel compensator receiving an input data signal, and performing channel compensation on the input data signal to generate a feed-in data signal, where a gain of said channel compensator is adjustable; a decoder connected to said channel compensator to receive the feed-in data signal, demultiplexing a to-be-decoded data signal that originates from the feed-in data signal into a number (P) of demultiplexed data signals, and decoding the demultiplexed data signals respectively into a number (P) of decoded signals, where P≥2, each of the decoded signals contains a plurality of samples, the samples of the decoded signals are generated sequentially, each of the samples of the decoded signals contains a data portion, and each of the samples of at least one of the decoded signals further contains an error portion; and an adaptive controller connected to said decoder to receive a decoded output that originates from the decoded signals, and further connected to said channel compensator; based on the decoded output, said adaptive controller generating an output data signal, and performing adaptive calibration on said channel compensator to adjust the gain of said channel compensator, wherein the adaptive calibration is performed with reference to the error portion of a first sample of the decoded signals and the data portion of a second sample of the decoded signals that is generated before the generation of the first sample of the decoded signals.
2 . The receiver as claimed in claim 1 , wherein: the input data signal is in a pulse amplitude modulation (PAM)-2 M format, where M≥2; the decoded signals includes a first decoded signal and a number (P−1) of second decoded signals; and said decoder includes a demultiplexer receiving the to-be-decoded data signal, and demultiplexing the to-be decoded data signal into the demultiplexed data signals, and a number (P) of analog to digital converters (ADCs), each of which is connected to said demultiplexer to receive a respective one of the demultiplexed data signals, one of said ADCs being an (M+1)-bit ADC, and performing analog to digital conversion on the respective one of the demultiplexed data signals to generate the first decoded signal containing a data portion that is M-bits wide and an error portion that is one-bit wide, each of the other one(s) of said ADCs being an M-bit ADC, and performing analog to digital conversion on the respective one of the demultiplexed data signals to generate a respective one of the second decoded signal containing a data portion that is M-bits wide.
3 . The receiver as claimed in claim 1 , wherein: the samples of the decoded signals are generated sequentially at a pace defined by a time interval; and the second sample of the decoded signals is generated before the generation of the first sample of the decoded signals by a number (K) of the time intervals, where 1≤K≤3.
4 . The receiver as claimed in claim 1 , wherein said adaptive controller increases the gain of said channel compensator when any one of the following conditions is met: the data portion of the second sample of the decoded signals is represented by a positive value, and the error portion of the first sample of the decoded signals is at a logic value “1”; and the data portion of the second sample of the decoded signals is represented by a negative value, and the error portion of the first sample of the decoded signals is at a logic value “0”.
5 . The receiver as claimed in claim 1 , wherein said adaptive controller decreases the gain of said channel compensator when any one of the following conditions is met: the data portion of the second sample of the decoded signals is represented by a positive value, and the error portion of the first sample of the decoded signals is at a logic value “0”; and the data portion of the second sample of the decoded signals is represented by a negative value, and the error portion of the first sample of the decoded signals is at a logic value “1”.
6 . A receiver comprising: a voltage regulator generating a reference voltage, a magnitude of which is adjustable; a decoder connected to said voltage regulator to receive the reference voltage, demultiplexing a to-be decoded data signal into a number (P) of demultiplexed data signals, and decoding the demultiplexed data signals respectively into a number (P) of decoded signals based on the reference voltage, where P≥2, each of the decoded signals contains a plurality of samples, the samples of the decoded signals are generated sequentially, each of the samples of the decoded signals contains a data portion, and each of the samples of at least one of the decoded signals further contains an error portion; and an adaptive controller connected to said decoder to receive a decoded output that originates from the decoded signals, and further connected to said voltage regulator; based on the decoded output, said adaptive controller generating an output data signal, and performing adaptive calibration on said voltage regulator to adjust the magnitude of the reference voltage, wherein the adaptive calibration is performed with reference to the error portion and the data portion of a sample of the decoded signals.
7 . The receiver as claimed in claim 6 , wherein: the to-be-decoded data signal is in a pulse amplitude modulation (PAM)-2 M format, where M≥2; the decoded signals includes a first decoded signal and a number (P−1) of second decoded signals; and said decoder includes a demultiplexer receiving the to-be-decoded data signal, and demultiplexing the to-be decoded data signal into the demultiplexed data signals, and a number (P) of analog to digital converters (ADCs), each of which is connected to said demultiplexer to receive a respective one of the demultiplexed data signals, and is further connected to said voltage regulator to receive the reference voltage, one of said ADCs being an (M+1)-bit ADC, and performing analog to digital conversion on the respective one of the demultiplexed data signals based on the reference voltage to generate the first decoded signal containing a data portion that is M-bits wide and an error portion that is one-bit wide, each of the other one(s) of said ADCs being an M-bit ADC, and performing analog to digital conversion on the respective one of the demultiplexed data signals based on the reference voltage to generate a respective one of the second decoded signals containing a data portion that is M-bits wide.
8 . The receiver as claimed in claim 6 , wherein said adaptive controller increases the magnitude of the reference voltage when any one of the following conditions is met: the data portion of the sample of the decoded signals is represented by a positive value, and the error portion of the sample of the decoded signals is at a logic value “1”; and the data portion of the sample of the decoded signals is represented by a negative value, and the error portion of the sample of the decoded signals is at a logic value “0”.
9 . The receiver as claimed in claim 6 , wherein said adaptive controller decreases the magnitude of the reference voltage when any one of the following conditions is met: the data portion of the sample of the decoded signals is represented by a positive value, and the error portion of the sample of the decoded signals is at a logic value “0”; and the data portion of the sample of the decoded signals is represented by a negative value, and the error portion of the sample of the decoded signals is at a logic value “1”.
10 . A receiver comprising: a phase interpolator receiving a clock input, and performing phase interpolation on the clock input to generate a number (N) of interpolated clock signals, where N≥2 and a phase shift of each of the interpolated clock signals with respect to the clock input is adjustable; a decoder device including a number (N) of decoders; each of said decoders being connected to said phase interpolator to receive a respective one of the interpolated clock signals, and delaying the respective one of the interpolated clock signals to generate a deskewed clock signal, where a delay of the deskewed clock signal with respect to the respective one of the interpolated clock signals is adjustable; said decoders cooperating with each other to receive a feed-in data signal, and to demultiplex, based on the deskewed clock signals generated by said decoders, the feed-in data signal into a number (N) of first demultiplexed data signals that are respectively provided by said decoders; each of said decoders buffering the first demultiplexed data signal provided thereby to generate a to-be-decoded data signal, demultiplexing the to-be decoded data signal into a number (P) of second demultiplexed data signals, and decoding the second demultiplexed data signals respectively into a number (P) of decoded signals, where P≥2, each of the decoded signals contains a plurality of samples, the samples of the decoded signals are generated sequentially, each of the samples of the decoded signals contains a data portion, and each of the samples of at least one of the decoded signals further contains an error portion; and an adaptive controller connected to said decoder device to receive a decoded output that originates from the decoded signals generated by said decoders, and further connected to said phase interpolator; based on the decoded output, said adaptive controller generating an output data signal, and performing adaptive calibration on said phase interpolator and said decoders to adjust the phase shifts of the interpolated clock signals and the delays of the deskewed clock signals; wherein the samples of the decoded signals are generated sequentially at a pace defined by a time interval; and wherein said adaptive controller performs adaptive calibration on said phase interpolator to adjust the phase shifts of the interpolated clock signals with reference to the error portion and the data portion of a first sample of the decoded signals and the error portion and the data portion of a second sample of the decoded signals that is generated after the generation of the first sample of the decoded signals by the time interval.
11 . The receiver as claimed in claim 10 , wherein: the feed-in data signal is in a pulse amplitude modulation (PAM)-2 M format, where M≥2; the decoded signals includes a first decoded signal and a number (P−1) of second decoded signals; each of said decoders includes a deskewer, a first demultiplexer, a buffer, a second demultiplexer and a number (P) of analog to digital converters (ADCs); for each of said decoders, said deskewer is connected to said phase interpolator to receive the respective one of the interpolated clock signals, and delaying the respective one of the interpolated clock signals to generate the deskewed clock signal, and said first demultiplexer is connected to said deskewer to receive the deskewed clock signal; said first demultiplexers of said decoders cooperates with each other to receive the feed-in data signal, and to demultiplex, based on the deskewed clock signals generated by said deskewers of said decoders, the feed-in data signal into the first demultiplexed data signals that are respectively outputted by said first demultiplexers; and for each of said decoders, said buffer is connected to said first demultiplexer to receive the first demultiplexed data signal outputted by said first demultiplexer, and buffers the first demultiplexed data signal to generate the to-be-decoded data signal, said second demultiplexer is connected to said buffer to receive the to-be-decoded data signal, and demultiplexes the to-be decoded data signal into the second demultiplexed data signals, each of said ADCs is connected to said second demultiplexer to receive a respective one of the second demultiplexed data signals, one of said ADCs is an (M+1)-bit ADC, and performs analog to digital conversion on the respective one of the second demultiplexed data signals to generate the first decoded signal containing a data portion that is M-bits wide and an error portion that is one-bit wide, and each of the other one(s) of said ADCs is an M-bit ADC, and performs analog to digital conversion on the respective one of the second demultiplexed data signals to generate a respective one of the second decoded signals containing a data portion that is M-bits wide.
12 . The receiver as claimed in claim 10 , wherein the feed-in data signal is in a PAM-2 M format, where M≥2, and said adaptive controller adjusts the phase shifts of the interpolated clock signals to defer phases of the interpolated clock signals when any one of the following conditions is met: the data portion of the first sample of the decoded signals is represented by a value of +L, the data portion of the second sample of the decoded signals is represented by a value of −L, the error portion of the first sample of the decoded signals is at a logic value “1”, and the error portion of the second sample of the decoded signals is at the logic value “1”, where L is a positive odd integer smaller than 2 M ; and the data portion of the first sample of the decoded signals is represented by a value of −L, the data portion of the second sample of the decoded signals is represented by a value of +L, the error portion of the first sample of the decoded signals is at a logic value “0”, and the error portion of the second sample of the decoded signals is at the logic value “0”.
13 . The receiver as claimed in claim 10 , wherein the feed-in data signal is in a PAM-2 M format, where M≥2, and said adaptive controller adjusts the phase shifts of the interpolated clock signals to advance phases of the interpolated clock signals when any one of the following conditions is met: the data portion of the first sample of the decoded signals is represented by a value of +L, the data portion of the second sample of the decoded signals is represented by a value of −L, the error portion of the first sample of the decoded signals is at a logic value “0”, and the error portion of the second sample of the decoded signals is at the logic value “0”, where L is a positive odd integer smaller than 2 M ; and the data portion of the first sample of the decoded signals is represented by a value of −L, the data portion of the second sample of the decoded signals is represented by a value of +L, the error portion of the first sample of the decoded signals is at a logic value “1”, and the error portion of the second sample of the decoded signals is at the logic value “1”.
14 . The receiver as claimed in claim 10 , wherein: said adaptive controller performs adaptive calibration on said decoders to adjust the delays of the deskewed clock signals with reference to the error portion and the data portion of a first sample of the decoded signals, the error portion and the data portion of a second sample of the decoded signals that is generated after the generation of the first sample of the decoded signals by the time interval, the data portion of a third sample of the decoded signals that is generated before the generation of the first sample of the decoded signals by the time interval, and the data portion of a fourth sample of the decoded signals that is generated after the generation of the second sample of the decoded signals by the time interval.
15 . The receiver as claimed in claim 14 , wherein the feed-in data signal is in a PAM-2 M format, where M≥2, and said adaptive controller adjusts the delays of the deskewed clock signals to decrease a skew between two of the deskewed clock signals respectively generated by two of said decoders respectively generating the first sample and the second sample of the decoded signals when any one of the following conditions is met: the data portion of the third sample of the decoded signals is represented by a value of +L, the data portion of the first sample of the decoded signals is represented by a value of +L, the data portion of the second sample of the decoded signals is represented by a value of −L, the data portion of the fourth sample of the decoded signals is represented by a value of −L, the error portion of the first sample of the decoded signals is at a logic value “1”, and the error portion of the second sample of the decoded signals is at a logic value “0”, where L is a positive odd integer smaller than 2 M ; the data portion of the third sample of the decoded signals is represented by a value of −L, the data portion of the first sample of the decoded signals is represented by a value of −L, the data portion of the second sample of the decoded signals is represented by a value of +L, the data portion of the fourth sample of the decoded signals is represented by a value of +L, the error portion of the first sample of the decoded signals is at the logic value “0”, and the error portion of the second sample of the decoded signals is at the logic value “1”; the data portion of the third sample of the decoded signals is represented by a value of −L, the data portion of the first sample of the decoded signals is represented by a value of +L, the data portion of the second sample of the decoded signals is represented by a value of +L, the data portion of the fourth sample of the decoded signals is represented by a value of −L, the error portion of the first sample of the decoded signals is at the logic value “0”, and the error portion of the second sample of the decoded signals is at the logic value “0”; and the data portion of the third sample of the decoded signals is represented by a value of +L, the data portion of the first sample of the decoded signals is represented by a value of −L, the data portion of the second sample of the decoded signals is represented by a value of −L, the data portion of the fourth sample of the decoded signals is represented by a value of +L, the error portion of the first sample of the decoded signals is at the logic value “1”, and the error portion of the second sample of the decoded signals is at the logic value “1”.
16 . The receiver as claimed in claim 14 , wherein the feed-in data signal is in a PAM-2 M format, where M≥2, and said adaptive controller adjusts the delays of the deskewed clock signals to increase a skew between two of the deskewed clock signals respectively generated by two of said decoders respectively generating the first sample and the second sample of the decoded signals when any one of the following conditions is met: the data portion of the third sample of the decoded signals is represented by a value of +L, the data portion of the first sample of the decoded signals is represented by a value of +L, the data portion of the second sample of the decoded signals is represented by a value of −L, the data portion of the fourth sample of the decoded signals is represented by a value of −L, the error portion of the first sample of the decoded signals is at a logic value “0”, and the error portion of the second sample of the decoded signals is at a logic value “1”, where L is a positive odd integer smaller than 2 M ; the data portion of the third sample of the decoded signals is represented by a value of −L, the data portion of the first sample of the decoded signals is represented by a value of −L, the data portion of the second sample of the decoded signals is represented by a value of +L, the data portion of the fourth sample of the decoded signals is represented by a value of +L, the error portion of the first sample of the decoded signals is at the logic value “1”, and the error portion of the second sample of the decoded signals is at the logic value “0”; the data portion of the third sample of the decoded signals is represented by a value of −L, the data portion of the first sample of the decoded signals is represented by a value of +L, the data portion of the second sample of the decoded signals is represented by a value of +L, the data portion of the fourth sample of the decoded signals is represented by a value of −L, the error portion of the first sample of the decoded signals is at the logic value “1”, and the error portion of the second sample of the decoded signals is at the logic value “1”; and the data portion of the third sample of the decoded signals is represented by a value of +L, the data portion of the first sample of the decoded signals is represented by a value of −L, the data portion of the second sample of the decoded signals is represented by a value of −L, the data portion of the fourth sample of the decoded signals is represented by a value of +L, the error portion of the first sample of the decoded signals is at the logic value “0”, and the error portion of the second sample of the decoded signals is at the logic value “0”.

Description

FIELD The disclosure relates to a receiver, and more particularly to a receiver performing adaptive calibration. BACKGROUND The Serializer/Deserializer (SerDes) function is widely used in communication standards (e.g., Ethernet, peripheral component interconnect express (PCIe), universal serial bus (USB), etc.) and extra-short reach (XSR) applications (e.g., package-to-package computing chips, optical communication chips, etc.). It is important that a receiver for converting serial input data into parallel output data can deal with channel loss, and process, voltage and temperature (PVT) variations so as to operate more stably and achieve a higher yield. SUMMARY Therefore, an object of the disclosure is to provide a receiver that can deal with at least one of channel loss, process variation, voltage variation or temperature variation. According to an aspect of the disclosure, the receiver includes a channel compensator, a decoder and an adaptive controller. The channel compensator receives an input data signal, and performs channel compensation on the input data signal to generate a feed-in data signal, where a gain of the channel compensator is adjustable. The decoder is connected to the channel compensator to receive the feed-in data signal, demultiplexes a to-be-decoded data signal that originates from the feed-in data signal into a number (P) of demultiplexed data signals, and decodes the demultiplexed data signals respectively into a number (P) of decoded signals, where P≥2, each of the decoded signals contains a plurality of samples, the samples of the decoded signals are generated sequentially, each of the samples of the decoded signals contains a data portion, and each of the samples of at least one of the decoded signals further contains an error portion. The adaptive controller is connected to the decoder to receive a decoded output that originates from the decoded signals, and is further connected to the channel compensator. Based on the decoded output, the adaptive controller generates an output data signal, and performs adaptive calibration on the channel compensator to adjust the gain of the channel compensator with reference to the error portion of a first sample of the decoded signals and the data portion of a second sample of the decoded signals that is generated before the generation of the first sample of the decoded signals. According to another aspect of the disclosure, the receiver includes a voltage regulator, a decoder and an adaptive controller. The voltage regulator generates a reference voltage, a magnitude of which is adjustable. The decoder is connected to the voltage regulator to receive the reference voltage, demultiplexes the to-be decoded data signal into a number (P) of demultiplexed data signals, and decodes the demultiplexed data signals respectively into a number (P) of decoded signals based on the reference voltage, where P≥2, each of the decoded signals contains a plurality of samples, the samples of the decoded signals are generated sequentially, each of the samples of the decoded signals contains a data portion, and each of the samples of at least one of the decoded signals further contains an error portion. The adaptive controller is connected to the decoder to receive a decoded output that originates from the decoded signals, and is further connected to the voltage regulator. Based on the decoded output, the adaptive controller generates an output data signal, and performs adaptive calibration on the voltage regulator to adjust the magnitude of the reference voltage with reference to the error portion and the data portion of a sample of the decoded signals. According to yet another aspect of the disclosure, the receiver includes a phase interpolator, a decoder device and an adaptive controller. The phase interpolator receives a clock input, and performs phase interpolation on the clock input to generate a number (N) of interpolated clock signals, where N≥2 and a phase shift of each of the interpolated clock signals with respect to the clock input is adjustable. The decoder device includes a number (N) of decoders. Each of the decoders is connected to the phase interpolator to receive a respective one of the interpolated clock signals, and delays the respective one of the interpolated clock signals to generate a deskewed clock signal, where a delay of the deskewed clock signal with respect to the respective one of the interpolated clock signals is adjustable. The decoders cooperate with each other to receive a feed-in data signal, and to demultiplex, based on the deskewed clock signals generated by the decoders, the feed-in data signal into a number (N) of first demultiplexed data signals that are respectively provided by the decoders. Each of the decoders buffers the first demultiplexed data signal provided thereby to generate a to-be-decoded data signal, demultiplexes the to-be decoded data signal into a number (P) of second demultiplexed data signals, and decodes