# US 10,771,100 B1 · Method and apparatus for efficient fast retraining of ethernet transceivers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,771,100 B1 - Document ID: US10771100B1 - Status: Granted - Kind: B1 - Application number: 16/362,494 - Filed: 2019-03-22 - Granted: 2020-09-08 - Earliest claimed: 2019-03-22 - Assignees: Marvell Asia Pte Ltd - Applicants: Aquantia Corporation - Inventors: Seid Alireza Razavi Majomard; Hossein Sedarat; Dragan Labalo - Web page: https://patentgrep.com/patent/US10771100B1 ## CPC - H04B 1/12: Neutralising, balancing, or compensation arrangements - H04L 25/03114: {non-adaptive, i.e. not adjustable, manually adjustable, or adjustable only during the reception of special signals} - H04B 1/40: Circuits - H04L 12/413: with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD] - H04L 5/1438: {Negotiation of transmission parameters prior to communication (modified according to link quality H04L1/0001)} - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A method of operation for an Ethernet transceiver is disclosed. The method includes entering a fast retrain sequence of steps. The fast retrain sequence of steps includes transferring two-level symbols to a link partner; and directly following transferring of the two-level symbols, transferring multi-level symbols to the link partner, the multi-level symbols having greater than two symbol levels. ## Claims ### Claim 1 A method of operation for an Ethernet transceiver, the method comprising: entering a fast retrain sequence of steps, the fast retrain sequence of steps including transferring two-level symbols to a link partner without transferring Tomlinson-Harashima Precoder (THP) coefficient information; and directly following transferring of the two-level symbols, transferring multi-level symbols to the link partner, the multi-level symbols having greater than two symbol levels. ### Claim 2 (depends on 1) The method according to claim 1, wherein the transferring two-level symbols to a link partner comprises: selectively transferring uncoded two-level symbols to a link partner; and selectively transferring coded two-level symbols to the link partner. ### Claim 3 (depends on 2) The method according to claim 2, wherein the coded two-level symbols are encoded in accordance with Tomlinson-Harashima Precoder (THP) coefficients. ### Claim 4 (depends on 1) The method according to claim 1, further comprising: informing the link partner to proceed directly to transferring the multi-level symbols following the transferring of the two-level symbols. ### Claim 5 (depends on 4) The method according to claim 4, wherein the informing is carried out via an InfoField protocol. ### Claim 6 (depends on 1) The method according to claim 1, wherein: the two-level symbols comprise PAM-2 symbols; and the multi-level symbols comprise PAM-16 symbols. ### Claim 7 (depends on 1) The method according to claim 1, further comprising: during the fast retrain sequence of steps, cancelling correlated noise received by a receiver with a correlated noise canceller. ### Claim 8 An integrated circuit (IC) Ethernet transceiver chip comprising: receiver circuitry including correlated noise canceller circuitry; and training logic to control a fast retrain sequence, the fast retrain sequence including a transfer of uncoded two-level symbols to a link partner; a transfer of coded two-level symbols to the link partner following the transfer of the uncoded two-level symbols without transferring Tomlinson-Harashima Precoder (THP) coefficient information; and directly following the transfer of the coded two-level symbols, the training logic to control a transfer of multi-level symbols to the link partner, the multi-level symbols having greater than two symbol levels. ### Claim 9 (depends on 8) The IC Ethernet transceiver chip of claim 8, wherein the transfer of two-level symbols comprises: a transfer of uncoded two-level symbols to a link partner; and a transfer of coded two-level symbols to the link partner. ### Claim 10 (depends on 9) The IC Ethernet transceiver chip according to claim 9, wherein: the coded two-level and multi-level symbols are encoded in accordance with a Tomlinson-Harashima Precoder (THP) encoding. ### Claim 11 (depends on 8) The IC Ethernet transceiver chip according to claim 8, wherein: the two-level symbols comprise PAM-2 symbols; and the multi-level symbols comprise PAM-16 symbols. ### Claim 12 (depends on 8) The IC Ethernet transceiver chip according to claim 8, realized as an NGBASE-T IC Ethernet transceiver chip. ### Claim 13 A method of operation for an Ethernet transceiver, the method comprising: for a first mode of operation, performing a training sequence by transferring two-level symbols to a link partner; and directly following transferring of the two-level symbols, transferring multi-level symbols to the link partner, the multi-level symbols having greater than two symbol levels; and for a second mode of operation, performing the training sequence by transferring uncoded two-level symbols to a link partner; exchanging updated precoder coefficients with the link partner, transferring coded two-level symbols to the link partner, the coding consistent with the updated precoder coefficients, and transferring multi-level symbols to the link partner, the multi-level symbols encoded consistent with the exchanged updated precoder coefficients and having greater than two symbol levels. ### Claim 14 (depends on 13) The method according to claim 13, wherein for the first mode of operation, the transferring two-level symbols to a link partner comprises: selectively transferring uncoded two-level symbols to a link partner; and selectively transferring coded two-level symbols to the link partner. ### Claim 15 (depends on 13) The method according to claim 13, wherein a selection between using the first mode of operation or the second mode of operation is based on a signal quality parameter. ### Claim 16 (depends on 13) The method according to claim 13, wherein the precoder encoding comprises: a Tomlinson-Harashima Precoder (THP) encoding. ### Claim 17 (depends on 13) The method according to claim 13, wherein the first mode of operation further comprises: informing the link partner to proceed directly to transferring the multi-level symbols following the transferring of the coded two-level symbols to the link partner. ### Claim 18 (depends on 17) The method according to claim 17, wherein the informing is carried out via an InfoField protocol.