Master/slave transceiver power back-off

• US 8,804,582 B1
• Filed: 08/23/2013
• Issued: 08/12/2014
• Est. Priority Date: 05/22/2006
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Aquantia Corporation (Marvell Technology Group Limited)
• Inventors: Taich, Dimitry, Tellado, Jose
• Primary Examiner(s): Wu, Jianye
• Application Number:
  US13/974,551
• Time in Patent Office: 354 Days
• US Class Current: 370/282
• CPC Class Codes: H04L 12/10 Current supply arrangements

Abstract

An apparatuses and methods of setting power back-off of a master transceiver and a slave transceiver is disclosed. One example of a method includes the master transceiver determining a master power back-off, and the slave transceiver determining a slave power back-off based on signals received from the master transceiver, and based on the master power back-off. One example of an apparatus includes a master transceiver and slave transceiver system. The slave transceiver is connected to the master transceiver through a cable. The master transceiver includes means for determining a master power back-off. The slave transceiver includes means for determining a slave power back-off based on signals received from the master transceiver, and based on the master power back-off.

Claims

1. A method of operation in an Ethernet transceiver, the method comprising:

in an initialization mode

transmitting signals to a link partner transceiver via a link;

applying an initial power back off parameter to the signals;

receiving a request from the link partner transceiver to adjust the initial power back off parameter, the request generated based on a detected signal power level of the signals as received by the link partner transceiver;

adjusting the initial power back off parameter to an adjusted value in response to the request;

setting the Ethernet transceiver power back off parameter to the adjusted value;

communicating the adjusted value to the link partner transceiver; and

in a normal operation mode

transmitting first data to the link partner transceiver using the adjusted value for the power back off parameter; and

receiving second data from the link partner transceiver, the second data having been transmitted with a power back off parameter that is constrained to be within a predefined range of the adjusted value.

2. The method according to claim 1, wherein:

during the initialization mode

identifying the Ethernet transceiver as a master device; and

identifying the link partner transceiver as a slave device.

3. The method according to claim 1, wherein a length of the link is not greater than 100 meters.

4. The method according to claim 3, wherein the Ethernet transceiver is realized as a 10 GBASE-T transceiver.

5. The method according to claim 1, further comprising:

iteratively performing the transmitting, receiving and adjusting until a threshold signal power level is detected, and a corresponding final value of the power back off parameter identified.

6. The method according to claim 5, wherein the threshold signal power level is a minimum signal power based on a desired signal power versus crosstalk parameter.

7. The method according to claim 5, wherein communicating the adjusted value includes the link parameter transceiver setting its power back off to within the predetermined range of the final value.

8. The method according to claim 1, wherein the predefined range is less than 6 db.

9. A method of operation in an Ethernet transceiver, the method comprising:

receiving transmit signals from a link partner transceiver via a link with an applied initial power back off parameter;

detecting a signal power level associated with the received transmit signals;

generating a request to adjust the initial power back off parameter based on the detected signal power level;

transmitting the request to the link partner transceiver, the link partner transceiver to adjust the power back off parameter to an adjusted value in response to receiving the request;

receiving the adjusted value of the power back off parameter for the link partner transceiver;

setting the power back off parameter for the Ethernet transceiver within a predefined level of the adjusted value set by the link partner transceiver.

10. The method according to claim 9, wherein:

the predefined range of values is less than 6 db within the final value.

11. The method according to claim 9, wherein:

during an initialization mode

identifying the Ethernet transceiver as a slave device; and

identifying the link partner transceiver as a master device.

12. The method according to claim 9, wherein:

detecting a signal power level includes determining the signal power of the received transmit signals using on-chip logic.

13. The method according to claim 9, and further comprising:

iteratively performing the receiving, detecting, generating and transmitting until a threshold signal power level is reached, and a corresponding final value of the power back off parameter identified for the link partner transceiver.

14. The method according to claim 11, wherein detecting a signal power level includes:

retrieving the threshold signal power level from a look-up table in the on-chip logic; and

comparing the detected signal power level to the threshold signal power level.

15. A method of setting power back off levels for first and second Ethernet transceivers coupled via an Ethernet link, the method comprising:

assigning an initial power back off to the first Ethernet transceiver;

transmitting signals from the first Ethernet transceiver to the second Ethernet transceiver,

the transmitted signals attenuated by an amount corresponding to the initial power back off;

receiving the transmitted signals at the second Ethernet transceiver;

detecting a signal power level associated with the received signals;

determining a signal power margin where the signal power may be reduced and still maintain acceptable signal quality;

if the signal power margin is above a threshold, transmitting a request from the second Ethernet transceiver to the first Ethernet transceiver, the request specifying an adjustment to the initial power back off;

setting the power back off for the first Ethernet transceiver to an adjusted value corresponding to the adjustment;

communicating the adjusted value of the power back off to the second Ethernet transceiver; and

setting the power back off for the second Ethernet transceiver to within a predetermined level of the adjusted value.

16. The method according to claim 15, further comprising:

iteratively carrying out the transmitting, receiving, detecting, and determining until the detected signal power reaches a signal power threshold.

17. The method according to claim 15, further comprising:

identifying the first Ethernet transceiver as a master device; and

identifying the second Ethernet transceiver as a slave device.

18. The method according to claim 15, wherein a length of the Ethernet link is not greater than 100 meters.

19. The method according to claim 15, wherein the first and second Ethernet transceivers are realized as 10 GBASE-T transceivers.

20. The method according to claim 15, further comprising:

iteratively performing the transmitting, receiving and adjusting until a threshold signal power level is detected, and a corresponding final value of the power back off parameter identified.

21. The method according to claim 20, wherein the threshold signal power level is a minimum signal power based on a desired signal power versus crosstalk parameter.