Intelligent power balancing for NBASE-T ethernet

1. A method of operation in an Ethernet integrated circuit (IC) chip having multiple channels, the method comprising:

during an offline mode of operation,

measuring a signal-to-noise ratio (SNR) for each of the channels with a receiver corresponding to each channel;

determining a transmit power level for a link partner transmitter, the transmit power level representing a minimum power level at the link partner transmitter that results in the measured SNR value at the receiver satisfying a predetermined SNR threshold;

communicating the transmit power level to the link partner transmitter; and

during an on-line mode of operation,

transceiving first Ethernet data based on the determined transmit power level; and

updating the determined transmit power level by

measuring a run-time SNR,

determining an updated transmit power level based on the measured run-time SNR,

communicating the updated transmit power level to the link partner transmitter, and

transceiving second Ethernet data based on the updated transmit power level.

2. The method of claim 1 , wherein the measuring, determining and communicating are carried out in accordance with a fast-retrain sequence during a normal operation mode with the link in the on-line mode of operation.

3. The method of claim 1 , wherein the communicating is carried out via an Info-Field exchange protocol.

4. The method of claim 1 , further comprising:

receiving Ethernet data from a transmitter transmitting with a given transmit power level;

measuring the SNR of the received Ethernet data; and

monitoring whether the measured SNR exceeds a minimum SNR threshold level.

5. The method of claim 4 , wherein the receiving, measuring and monitoring is carried out during the online mode of operation.

6. An Ethernet integrated circuit (IC) chip, the Ethernet IC chip comprising:

interface circuitry for coupling to multiple channels;

receiver circuitry to receive signals from multiple channels via the interface circuitry;

logic coupled to the interface circuitry, the logic operable to, for each of the multiple channels

during an offline mode of operation,

measure a signal-to-noise ratio (SNR) value for signals received over a given one of the multiple channels,

determine a transmit power level representing a minimum power level at the link partner transmitter that results in the measured SNR value at the receiver satisfying a predetermined SNR threshold; and

during an online mode of operation,

updating the determined transmit power level by

measuring a run-time SNR,

determining an updated transmit power level based on the measured run-time SNR, and

transmitter circuitry to transmit the updated transmit power level to the link partner transmitter.

7. The Ethernet IC chip of claim 6 , wherein the logic is operable to measure the SNR values and determine the transmit power levels during a fast-retrain sequence.

8. The Ethernet IC chip of claim 6 , wherein the transmitter transmits the transmit power level value in accordance with an Info-Field exchange protocol.

9. The Ethernet IC chip of claim 6 , wherein the receiver circuitry is operable to receive Ethernet data from the link partner transmitter, transmitting at the transmit power level, for each of the multiple channels, and wherein the logic is operable to measure the SNR of the received Ethernet data to monitor that the SNR exceeds a minimum SNR threshold level.

10. The Ethernet IC chip of claim 9 , wherein the receiver circuitry receives the Ethernet data and the logic is operable to measure the SNR values with the link in the online mode of operation.