PRECODING DURING LINK ESTABLISHMENT
Examples described herein relate to an Ethernet physical layer transceiver (PHY) circuitry for use in frame communication with a remote link partner. In some example, the Ethernet PHY circuitry can include Physical Medium Dependent (PMD) circuitry and transmitter circuitry and receiver circuitry for use in the frame communication. In some examples, the PMD circuitry is to perform link training with a partner transmitter and selectively request the partner transmitter to apply a modulation scheme with precoding during the link training based on a magnitude of one or more equalizer coefficient values.
1 . An apparatus comprising:
Ethernet physical layer transceiver (PHY) circuitry for use in frame communication with a remote link partner, the Ethernet PHY circuitry comprising:
Physical Medium Dependent (PMD) circuitry; and
transmitter circuitry and receiver circuitry for use in the frame communication, wherein:
the PMD circuitry is to perform link training with a partner transmitter and selectively request the partner transmitter to apply a modulation scheme with precoding during the link training based on a magnitude of one or more equalizer coefficient values,
the modulation scheme comprises Pulse Amplitude Modulation 4-level (PAM-4) or Pulse Amplitude Modulation 6-level (PAM-6), and
the request the partner transmitter to apply the modulation scheme with precoding during the link training comprises transmission of a control signal to the partner transmitter.
2 . The apparatus of claim 1 , wherein the control signal comprises a modulation and precoding request.
3 . The apparatus of claim 1 , wherein the equalizer coefficient values comprise one or more of: Decision Feedback Equalizer (DFE) pre-cursor coefficient values, main coefficient values, or post-cursor coefficient values, feed forward equalizers (FFEs) coefficient values, or Maximum Likelihood Sequence Estimation (MLSE) equalizer coefficient values.
4 . The apparatus of claim 1 , wherein the PMD circuitry is to not request the partner transmitter to use a modulation scheme with precoding based on a magnitude of one or more equalizer coefficient values.
5 . The apparatus of claim 4 , comprising circuitry to apply forward error correction (FEC) to correct errors in a received signal from the partner transmitter.
6 . The apparatus of claim 1 , comprising circuitry to request equalizer setting adjustment by the partner transmitter based on the link training.
7 . A non-transitory computer-readable medium comprising instructions stored thereon, that if executed by one or more processors, cause the one or more processors to:
execute an operating system (OS) to configure circuitry of a network interface device to:
enable performance of link training and selectively request a partner transmitter to use a modulation scheme with precoding during the link training based on a magnitude of one or more equalizer coefficient values.
8 . The computer-readable medium of claim 7 , wherein the modulation scheme comprises Pulse Amplitude Modulation 4-level (PAM-4) or Pulse Amplitude Modulation 6-level (PAM-6).
9 . The computer-readable medium of claim 7 , wherein the request the partner transmitter to apply the modulation scheme with precoding during the link training is based on transmission of a control signal to the partner transmitter.
10 . The computer-readable medium of claim 9 , wherein the control signal comprises a modulation and precoding request.
11 . The computer-readable medium of claim 7 , wherein the equalizer coefficient values comprise one or more of: Decision Feedback Equalizer (DFE) pre-cursor coefficient values, main coefficient values, or post-cursor coefficient values, feed forward equalizers (FFEs) coefficient values, or Maximum Likelihood Sequence Estimation (MLSE) equalizer coefficient values.
12 . The computer-readable medium of claim 7 , wherein the circuitry is to not request the partner transmitter to use a modulation scheme with precoding based on a magnitude of one or more equalizer coefficient values.
13 . The computer-readable medium of claim 7 , wherein the OS is to selectively disable the circuitry of the network interface device from use of a modulation scheme with precoding during the link training based on a magnitude of one or more equalizer coefficient values.
14 . A method comprising:
Physical Medium Dependent (PMD) circuitry performing link training with a partner transmitter and selectively request the partner transmitter to apply a modulation scheme with precoding during the link training based on a magnitude of one or more equalizer coefficient values, wherein the modulation scheme comprises Pulse Amplitude Modulation 4-level (PAM-4) or Pulse Amplitude Modulation 6-level (PAM-6).
15 . The method of claim 14 , wherein the request the partner transmitter to apply the modulation scheme with precoding during the link training is based on transmission of a control signal to the partner transmitter.
16 . The method of claim 15 , wherein the control signal comprises a modulation and precoding request.
17 . The method of claim 14 , wherein the equalizer coefficient values comprise one or more of: Decision Feedback Equalizer (DFE) pre-cursor coefficient values, main coefficient values, or post-cursor coefficient values, feed forward equalizers (FFEs) coefficient values, or Maximum Likelihood Sequence Estimation (MLSE) equalizer coefficient values.
18 . The method of claim 14 , comprising:
the PMD circuitry not requesting the partner transmitter to use a modulation scheme with precoding based on a magnitude of one or more equalizer coefficient values.
19 . The method of claim 14 , comprising:
requesting equalizer setting adjustment by the partner transmitter based on the link training.