Interface for bridging out-of-band information and preventing false presence detection of terminating devices

• US 7,461,192 B2
• Filed: 12/15/2004
• Issued: 12/02/2008
• Est. Priority Date: 12/15/2004
• Status: Active Grant

• Current Assignee: Rambus Inc.
• Original Assignee: Rambus Inc.
• Inventors: Sobelman, Michael J.
• Primary Examiner(s): Auve; Glenn A.
• Assistant Examiner(s): VU, TRISHA U
• Application Number:
  US11/014,260
• Publication Number:
  US 20060129733A1
• Time in Patent Office: 1,448 Days
• Field of Search: 710/105, 710/260, 710/305, 710/316, 710/315, 710/100, 710/313, 370/402, 370/467, 370/389, 370/459, 370/219, 370/503, 714/799, 714/48, 341/59, 341/102, 341/58, 398/183, 439/378, 375/220, 375/242, 713/1, 713/324
• US Class Current: 710/305
• CPC Class Codes: G06F 13/4027 using bus bridges G06F13/4022 takes precedence
• CPC Class Codes: G06F 13/4282 on a serial bus, e.g. I2C bus, SPI bus on daisy chain buses G06F13/4247
• CPC Class Codes: G06F 13/4286 using a handshaking protocol, e.g. RS232C link
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H04L 25/0262 Arrangements for detecting the data rate of an incoming signal
• CPC Class Codes: H04L 25/4908 using mBnB codes

Abstract

A device includes a first interface to receive a signal from a first communication link, wherein the receive signal includes out-of-band (OOB) information. A detector coupled to the first interface detects the OOB information. An encoder coupled to the detector encodes the OOB information into one or more symbols (e.g., control characters). A second interface is coupled to the encoder and a second communication link (e.g., a serial transport path). The second interface transmits the symbols on the second communication link. The device also includes mechanisms for preventing false presence detection of terminating devices.

Claims

1. A circuit, comprising:

a first interface having an input that receives a signal including one or more multiple-bit symbols representing encoded out-of-band (OOB) information from a first communication link;

a decoder coupled to the first interface that decodes the one or more multiple-bit symbols into reconstructed OOB information; and

a second interface coupled to the decoder and having an output for transmitting the reconstructed OOB information to a second communication link.

2. The circuit of claim 1, wherein the first interface is coupled to a serial data link.

3. The circuit of claim 1, wherein the decoder is an 8B/10B decoder and the one or more multiple-bit symbols are 10-bit control characters.

4. The circuit of claim 1, wherein the encoded OOB information represents a “

Loss of Signal”

status on the first communication link.

5. The circuit of claim 1, wherein the encoded OOB information includes signal state information selected from the set comprising Electrical Idle, Receiver Detect, Beacon, COMReset/COMInit and COMWake.

6. The circuit of claim 1, wherein the received signal includes one or more data symbols corresponding to an in-band data signal, and the decoder decodes the data symbols to generate a data signal.

7. The circuit of claim 6, including a deserializer coupled to the decoder for deserializing the data symbols prior to decoding;

wherein the second interface includes a transmitter coupled to the decoder for transmitting the data signal on the second communication link.

8. A method of bridging out-of-band (OOB) information across a device, comprising:

encoding OOB information, including;

receiving a first signal from a first communication link, and

if the first signal includes OOB information;

identifying the OOB information,

selecting a symbol representing the OOB information, and

transmitting the symbol on a serial data communication link; and

decoding OOB information, including;

receiving a second signal comprising a plurality of multiple-bit symbols from the serial data communication link,

evaluating at least some of the symbols in the plurality of multiple-bit symbols to determine if any of the evaluated symbols is associated with OOB information, and

for any evaluated symbols that are associated with OOB information, and

decoding the evaluated symbol associated with OOB information to produce reconstructed OOB information.

9. The method of claim 8, wherein the OOB information comprises “

Loss of Signal”

.

10. The method of claim 8, wherein the OOB information includes signal state information selected from the set comprising Electrical Idle, Receiver Detect, Beacon, COMReset/COMInit and COMWake.

11. The method of claim 8, further comprising:

serializing the symbol prior to transmitting the symbol on the serial data communication link; and

transmitting the reconstructed OOB information on a second communication link.

12. A method of bridging out-of-band (OOB) information across a device, comprising:

receiving a signal comprising a plurality of multiple-bit symbols from a first communication link;

evaluating at least some of the symbols in the plurality of multiple-bit symbols to determine if any of the evaluated symbols is associated with OOB information; and

for any evaluated symbols that are associated with OOB information,

decoding the evaluated symbol associated with OOB information to produce reconstructed OOB information; and

transmitting the reconstructed OOB information on a second communication link.

13. The method of claim 12, wherein the OOB information comprises “

Loss of Signal”

.

14. The method of claim 12, wherein the OOB information includes signal state information selected from the set including Electrical Idle, Receiver Detect, Beacon, COMReset/COMInit and COMWake.

15. The method of claim 12, wherein the signal includes data symbols corresponding to an in-band data signal, the method further comprising:

deserializing the data symbols;

decoding the data symbols; and

transmitting a decoded data signal on the second communication link.

16. A system for bridging out-of-band (OOB) information across an interface, comprising:

means for receiving a first signal from a first communication link;

if the first signal comprises OOB information;

means for identifying the OOB information;

means for selecting a symbol representing the OOB information;

means for transmitting the symbol on a serial data communication link;

means for receiving a second signal including one or more multiple-bit symbols

representing encoded out-of-band (OOB) information from the serial data communication link; and

means for decoding the one or more multiple-bit symbols into reconstructed OOB information.

17. The system of claim 16, further comprising means for transmitting the reconstructed OOB information on a second communication link.

18. A computer readable storage medium containing data representing a circuit that includes:

a first circuit, including;

a first input interface to receive a signal from a first communication link, wherein the signal includes out-of band (OOB) information;

an encoder to encode the OOB information into corresponding symbols; and

a first output interface to transmit the symbols to a serial data communication link; and

a second circuit, including;

a second input interface to receive a signal including one or more multiple-bit symbols representing encoded out-of band (OOB) information from the serial data communication link; and

a decoder to decode the one or more multiple-bit symbols into reconstructed OOB information.

19. The storage medium of claim 18, further comprising a transmitter for transmitting the reconstructed OOB information on a second communication link.

20. A computer readable storage medium containing data representing a circuit that includes:

a first interface having an input that receives a signal including one or more multiple-bit symbols representing encoded out-of band (OOB) information from a first communication link;

a decoder coupled to the first interface that decodes the one or more multiple-bit symbols into reconstructed OOB information; and

a second interface coupled to the decoder and having an output for transmitting the reconstructed OOB information to a second communication link.

21. A circuit, comprising:

an encoding path, including;

a first input interface to receive a first signal from a first communication link, wherein the first signal includes out-of-band (OOB) information,

an encoder to encode the OOB information into corresponding symbols, and

a first output interface to transmit the symbols to a serial data communication link; and

a decoding path, including;

a second input interface to receive a second signal from the serial data communication link, the second signal including one or more multiple-bit symbols representing encoded out-of-band (OOB) information, and

a decoder to decode the one or more multiple-bit symbols into reconstructed OOB information.

22. The circuit of claim 21, wherein:

the encoding path further including a detector coupled to the first input interface to detect the OOB information, the encoder coupled to the detector,

the decoding path further including a second output interface for transmitting the reconstructed OOB information to a second communication link.

23. The circuit of claim 21, wherein the decoder is an 8B/10B decoder and the one or more multiple-bit symbols are 10-bit control characters.

24. The circuit of claim 21, wherein the second signal includes one or more data symbols corresponding to an in-band data signal, and the decoder decodes the data symbols to generate a data signal.

25. The circuit of claim 24, the decoding path including a deserializer coupled to the decoder for deserializing the data symbols prior to decoding.

26. The circuit of claim 21, wherein the encoder encodes at least a portion of the first signal received by the first input interface into a stream of data symbols corresponding to an in-band data signal.

27. The circuit of claim 26, wherein the encoder is an 8B/10B encoder and the symbols are control characters.

28. The circuit of claim 21, wherein the OOB information represents a “

Loss of Signal”

status on the first communication link.

29. The circuit of claim 21, wherein the OOB information includes signal state information selected from the set comprising Electrical Idle, Receiver Detect, Beacon, COMReset/COMInit and COMWake.

30. The circuit of claim 21, the encoding path further comprising:

a serializer coupled to the encoder to serialize the symbols prior to transmission by the first output interface.