Method and system for a multi-rate gigabit media independent interface

• US 7,720,068 B2
• Filed: 08/21/2007
• Issued: 05/18/2010
• Est. Priority Date: 08/23/2006
• Status: Expired

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: SolarFlare Communications Incorporated (Advanced Micro Devices, Inc.)
• Inventors: McClellan, Brett A.
• Primary Examiner(s): LY, ANH VU H
• Application Number:
  US11/894,990
• Publication Number:
  US 20080049788A1
• Time in Patent Office: 1,001 Days
• Field of Search: None
• US Class Current: 370/391
• CPC Class Codes: H04J 3/247 ATM or packet multiplexing
• CPC Class Codes: H04L 2212/00 Encapsulation of packets
• CPC Class Codes: H04L 27/0008 arrangements for allowing a transmitter or receiver to use more than one type of modulation negotiating modulation type for two-way transmission paths H04L5/1453
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/22 Traffic shaping
• CPC Class Codes: H04L 47/431 using padding or de-padding

Abstract

Disclosed is a UGMII system to interface multirate devices including 10 gigabit per second data exchange rates. Mode selection is enabled to provide for automatic detection and adaptation to any transmit rate including 10M, 100M, 1G, and 10G. Mode selection comprises the negotiation between the UGMII extension sublayers located at the MAC and PHY to select between one of several operational modes including: XGMII communication, GMII encapsulation, Clause 22 MDIO register management and Clause 45 MDIO register management. Selection of UGMII and XGMII operating modes are negotiated between the MAC and PHY using ordered sets to announce and acknowledgement a mode change. In one embodiment 802.3 Clause 46 defined ordered sets are utilized.

Claims

1. A rate adaptive interface configured to interface a MAC device with a PHY device, the interface comprising:

a rate adaptation module in communication with a MAC device, the rate adaptation module configured to;

receive data at a rate selected from 10 Mb/s, 100 Mb/s, and 1 Gb/s;

process the data to a rate of 1 Gb/s;

output the data at a rate of 1 Gb/s;

an encapsulation/recovery module configured to receive the data at a rate of 1 Gb/s from the rate adaptation module, and encapsulate the data at a rate of 1 Gb/s to generated data at a rate of 10 Gb/s;

a multiplexer configured to receive the data at a rate of 10 Gb/s from the encapsulation/recovery module or to received data from a MAC device at a rate of 10 Gb/s and selectively output data at a rate of 10 Gb/s responsive to a mode selection control signal;

a mode selection module configured to control the multiplexer based on control input from a higher layer device; and

an ordered set generation and detection module in communication with the multiplexer and the mode selection module, the ordered set generation and detection module configured to detect ordered sets which announce a mode change wherein the ordered set generation and detection module is in communication with the mode selection module.

2. The system of claim 1, wherein the encapsulation/recovery module is further configured to recover encapsulated data thereby changing the data rate from a 10 G data rate to a 1 G data rate.

3. The system of claim 1, wherein the mode selection module adjusts the data rate of operation between 10 Mb/s, 100 Mb/s, or 1 Gb/s.

4. The system of claim 1, wherein the encapsulation/recovery module is further configured with an input to receive data at a rate of 10 Gb/s and perform recovery thereon to output the data at a rate of 1 Gb/s.

5. A rate adaptive interface for use in a network device, the interface comprising:

A MAC device configured to output data from a first port at a variable first rate and from a second port at a second rate;

a rate adaptation module configured received data from the MAC at the variable first rate and convert the data at the variable first rate to data at the second rate;

an encapsulation module configured to receive data at the second rate from the rate adaptation module and convert the data at the second rate to data at a third rate;

a switch configured to interface with the encapsulation module and the MAC device to receive data at a rate of 10 Gb/s from either the encapsulation module or from the second port of the MAC device and output data at a rate of 10 Gb/s, the switch controlled by a mode selection control signal;

a mode selection module configured to provide the mode selection control signal to the switch to thereby control operation of the switch.

6. The interface of claim 5, further comprising an extension sublayer configured to receive data at a rate of 10 Gb/s from the switch, wherein the extension sublayer extends the distance which the data at a rate of 10 Gb/s may be transmitted.

7. The interface of claim 5, further comprising an ordered set generation and detection module configured interface with the switch to detect ordered sets which determine a mode change, wherein the ordered set generation and detection module is in communication with the mode selection module.

8. The interface of claim 5, wherein the encapsulation module is further configured to recover encapsulated data thereby changing the data rate from a 10 G data rate to a 1 G data rate.

9. The interface of claim 5, wherein data at the variable first rate comprises data at a rate of 10 Mb/s, 100 Mb/s, or 1 Gb/s, and data at the second rate comprises data at a rate of 1 Gb/s and data at the third rate comprises data at a rate of 10 Gb/s.

10. The interface of claim 5, wherein data at the third rate has a format that is different than the data at the second rate.

11. The interface of claim 5, wherein the switch comprises a multiplexer.

12. The interface of claim 5, further comprising a PHY Device configured to receive data at a rate of 10 Gb/s from the switch.

13. The interface of claim 5, wherein the first port and the second port comprise input/output ports and the switch is configured to receive and transmit data to either of the second port of the MAC device or the encapsulation module.

14. A method for interfacing a multirate MAC device with a PHY device in a network communication device, the method comprising:

outputting unprocessed data from the multirate MAC device at a variable rate to a rate adaptation module or at a first fixed rate to a multiplexer;

processing the data at the rate adaptation module to up-convert the data at a variable rate to data at a second fixed rate;

processing the data at the second fixed rate with an encapsulation module to generate processed data at the first fixed rate;

receiving, at a multiplexer, the unprocessed data from the MAC device at the first fixed rate or the processed data at the first fixed rate;

receiving, at the multiplexer, a mode selection signal and responsive to the mode selection signal, outputting from the multiplexer the unprocessed data at the first rate or the processed data at the first rate.

15. The method of claim 14, wherein the variable rate consists of 10 Mb/s, 100 Mb/s and 1 Gb/s.

16. The method of claim 14, wherein the first fixed rate comprises 10 Gb/s and the second fixed rate comprises 1 Gb/s.

17. The method of claim 14, wherein processing the data at the second fixed rate with an encapsulation module further comprise altering the format of the data.

18. The method of claim 14, further comprising outputting the data from the multiplexer to an extension sublayer, a PHY device, or a second multiplexer.

19. The method of claim 14, wherein up-sampling comprises padding or repeating data received at the variable rate to create data at a second fixed rate.

20. The method of claim 14, further comprising:

establishing a mode of operation;

receiving data at the first fixed rate at the multiplexer from a PHY device, an extension sublayer, or a second multiplexer;

responsive to the mode of operation, outputting the data at the first fixed rate to either the MAC device or to a recovery unit;

responsive to the outputting the data at the first fixed rate to a recovery unit, converting the data at the first fixed rate to the second fixed rate;

converting the data at the second fixed rate to data at a third fixed rate, wherein the data at the third fixed rate is a rate selected from a group of variable rates;

outputting the data at the third fixed rate to the MAC device.