Method and system for MAC and PHY synchronization for energy efficient networking

• US 9,008,125 B2
• Filed: 09/27/2013
• Issued: 04/14/2015
• Est. Priority Date: 04/15/2008
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Diab, Wael William
• Primary Examiner(s): Thier, Michael
• Assistant Examiner(s): HAILE, FEBEN
• Application Number:
  US14/039,209
• Publication Number:
  US 20140023095A1
• Time in Patent Office: 564 Days
• Field of Search: 370/311, 370/252, 370/503, 713320-324
• US Class Current: 370/503
• CPC Class Codes: G06F 1/3287 by switching off individual functional units in the computer system
• CPC Class Codes: H04J 3/0635 Clock or time synchronisation in a network timer in protocols H04L69/28
• CPC Class Codes: H04J 3/0685 Clock or time synchronisation in a node; Intranode synchronisation
• CPC Class Codes: H04L 12/12 Arrangements for remote connection or disconnection of substations or of equipment thereof
• CPC Class Codes: H04L 2007/045 Fill bit or bits, idle words
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

Aspects of a method and system for MAC and PHY synchronization for energy efficient networking are provided. In this regard, an interface that enables communication between a MAC controller and a PHY device may be configured to operate in an energy saving mode. While the interface is operating in an energy saving mode, synchronization between the MAC controller and the PHY device may be maintained by one or both of adjusting a clock generated for the interface and/or communicating dummy data via the interface. The clock may be adjusted by one or more of adjusting a frequency of the clock, adjusting an amplitude of the clock, and/or duty cycling the clock. The MAC controller and/or the PHY device may generate the dummy data. The PHY device and/or the MAC controller may discard the dummy data upon receiving the dummy data.

Claims

1. A method performed by a network device, comprising:

transitioning at least part of the network device from an active mode to an energy saving mode, the network device including a bus between a media access control device and a physical layer device, wherein during the energy saving mode, a first part of a media access control device interface coupled to the bus and a first part of a physical layer device interface coupled to the bus are powered down; and

while in the energy saving mode, operating a second part of the media access control device interface and/or a second part of the physical layer device interface in a powered mode that enables generation of an adjusted clock signal transmitted across the bus, wherein the adjusted clock signal has a reduced duty cycle lower than a duty cycle of a clock signal generated when the at least part of the network device is in the active mode, the adjusted clock signal having multiple periodic cycles in a first time period having a reduced frequency and/or amplitude, and a second time period where no clock signal is generated.

2. The method according to claim 1, wherein the adjusted clock signal is generated periodically.

3. The method according to claim 1, wherein the adjusted clock signal is generated aperiodically over one or more time intervals.

4. The method according to claim 1, wherein the adjusted clock signal is reduced in frequency.

5. The method according to claim 1, wherein the adjusted clock signal is reduced in amplitude.

6. The method according to claim 1, further comprising powering up the first part of the media access control device interface and the first part of the physical layer device interface when transitioning the at least part of the network device from the energy saving mode to the active mode.

7. A network device, comprising:

a media access control device including a media access control device interface;

a physical layer device including a physical layer device interface; and

a bus connected to the media access control device interface and to the physical layer device interface, wherein upon a transition of at least part of the network device from an active mode to an energy saving mode, a first part of the media access control device interface and a first part of a physical layer device interface coupled to the bus are powered down, while a second part of the media access control device interface and a second part of the physical layer device interface operate in a powered mode that enables generation of an adjusted clock signal transmitted across the bus, wherein the adjusted clock signal has a reduced duty cycle lower than a duty cycle of a clock signal generated when the at least part of the network device is in the active mode, the adjusted clock signal having multiple periodic cycles in a first time period having a reduced frequency and/or amplitude, and a second time period where no clock signal is generated.

8. The network device according to claim 7, wherein the adjusted clock signal is generated periodically.

9. The network device according to claim 7, wherein the adjusted clock signal is generated aperiodically over one or more time intervals.

10. The network device according to claim 7, wherein the adjusted clock signal is reduced in frequency.

11. The network device according to claim 7, wherein the adjusted clock signal is reduced in amplitude.

12. The network device according to claim 7, wherein the first part of the media access control device interface and the first part of the physical layer device interface are powered up when the at least part of the network device transitions from the energy saving mode to the active mode.

13. A method, comprising:

configuring an interface that enables communication between a media access control device and a physical layer device to operate in an energy saving mode upon a transition from an active mode; and

while the interface operates in the energy saving mode, adjusting a clock signal generated for transmission over the interface to maintain synchronization between the media access control device and the physical layer device, wherein the adjusted clock signal has a reduced duty cycle lower than a duty cycle of a clock signal generated when the interface operates in the active mode, the adjusted clock signal having multiple periodic cycles in a first time period having a reduced frequency and/or amplitude, and a second time period where no clock signal is generated.

14. The method according to claim 13, wherein the adjusted clock signal is generated periodically.

15. The method according to claim 13, wherein the adjusted clock signal is generated aperiodically over one or more time intervals.

16. The method according to claim 13, wherein the adjusted clock signal is reduced in frequency.

17. The method according to claim 13, wherein the adjusted clock signal is reduced in amplitude.