DETERMINATION OF PHYSICAL CONNECTIVITY STATUS OF DEVICES BASED ON ELECTRICAL MEASUREMENT

• US 20110193579A1
• Filed: 02/07/2011
• Published: 08/11/2011
• Est. Priority Date: 02/10/2010
• Status: Active Grant

• Current Assignee: Universal Connectivity Technologies Inc. (Wi-LAN Inc.)
• Original Assignee: Silicon Image, Inc. (Lattice Semiconductor Corporation)
• Inventors: Wong, Jason, Kim, Gyudong
• Granted Patent: US 9,234,930 B2
• Time in Patent Office: Days
• US Class Current: 324/713
• CPC Class Codes: G01R 31/58 Testing of lines, cables or conductors testing of electric windings G01R31/72
• CPC Class Codes: G06F 11/3055 Monitoring arrangements for monitoring the status of the computing system or of the computing system component, e.g. monitoring if the computing system is on, off, available, not available error or fault processing without redundancy G06F11/0703; error detection or correction by redundancy in data representation G06F11/08; error detection or correction by redundancy in operation G06F11/14; error detection or correction by redundancy in hardware G06F11/16
• CPC Class Codes: G06F 11/3485 for I/O devices
• CPC Class Codes: G06F 11/349 for interfaces, buses

Abstract

Embodiments of the invention are generally directed to determination of physical connectivity status of devices based on electrical measurement. An embodiment of a method includes discovering a connection of a first device with a second device, and performing an electrical measurement of the second device by the first device via the connection between the first device and the second device, where performing the electrical measurement includes sensing by the first device of an element of the second device. The method further includes, if the sensing by the first device fails to detect the element of the second device and a predetermined condition for the electrical measurement is enabled, then determining by the first device that the connection with the second device has been lost.

Claims

1. A method comprising:

discovering a connection of a first device with a second device;

performing an electrical measurement of the second device by the first device via the connection between the first device and the second device, wherein performing the electrical measurement includes sensing by the first device of an element of the second device; and

if the sensing by the first fails to detect the element of the second device and a predetermined condition for the electrical measurement is enabled, then determining by the first device that the connection with the second device has been lost.

2. The method of claim 1, wherein the element of the second device is a termination resistance, and wherein the electrical measurement is a measurement to determine the existence of the termination resistance in the second device.

3. The method of claim 2, wherein the predetermined condition is a connected status for a control bus between the first device and the second device, and wherein the electrical measurement includes sensing whether the termination resistance of the second device is coupled with the control bus.

4. The method of claim 3, wherein the termination resistance is not coupled with the control bus until a process of the second device for discovering the connection of the first device to the second device is completed.

5. The method of claim 1, wherein the first device is a data source device and the second device is a data sink device.

6. The method of claim 1, wherein the predetermined condition includes a certain time period during which a change in the electrical measurement indicates a loss in physical connection, a status of the electrical measure being ignored until the condition is true.

7. The method of claim 6, wherein comprising changing the predetermined condition to an invalid state after determining that the connection with the second device has been lost.

8. The method of claim 1, further comprising disconnecting a termination resistance of the first apparatus from the common node upon determining that the connection with the second device has been lost.

9. The method of claim 1, wherein discovering the connection of the first device with the second device includes discovering the connection pursuant to an interface protocol.

10. The method of claim 9, wherein the interface protocol is HDMI™

(High-Definition Multimedia Interface) protocol or MHL™

(Mobile High-Definition Link) protocol.

11. An apparatus comprising:

an interface for a connection with a second apparatus, wherein the apparatus is operable to discover the second apparatus; and

a reference-sensing element to perform an electrical measurement on a common node of the interface with the second apparatus to detect an element of the second apparatus;

wherein the apparatus is to determine that connectivity with the second apparatus is lost when the reference-sensing element fails to detect the element of the second apparatus.

12. The apparatus of claim 11, wherein the element of the second apparatus is a termination resistance.

13. The apparatus of claim 12, wherein the common node is a control bus, and wherein the electrical measurement detects the connection of the termination resistance with the control bus.

14. The apparatus of claim 11, wherein the electrical measurement is a measurement of a voltage or current on the common node.

15. The apparatus of claim 11, where the common node comprises a pair of differential nodes.

16. The apparatus of claim 11, wherein the apparatus is a source apparatus and the second apparatus is a sink apparatus, the source apparatus providing audio/video data to the sink apparatus.

17. The apparatus of claim 16, wherein the apparatus is an HDMI™

(High-Definition Multimedia Interface) or MHL™

(Mobile High-Definition Link) compatible apparatus.

18. The apparatus of claim 11, wherein the reference-sensing element provides a passive measurement that does not force a voltage or current on the common node between the apparatus and the second apparatus.

19. The apparatus of claim 11, wherein the reference-sensing element provides an active measurement forcing a fixed amount of voltage or current on the common node between the apparatus and the second apparatus.

20. A computer-readable medium having stored thereon data representing sequences of instructions that, when executed by a processor, cause the processor to perform operations comprising:

discovering a connection of a source device with a sink device, the source device to provide data to the sink device via the connection;

establishing a connected status between the source device and the sink device;

enabling a sensing element of the source device to detect a presence of a termination resistance of the sink device via an electrical measurement of a common node between the source device and the sink device; and

upon failing to detect the termination resistance on the common node, determining by the source device that the connection with the sink device has been lost and changing the connected status to an invalid state.

21. The medium of claim 20, further comprising instructions that, when executed by the processor, cause the processor to perform operations comprising:

disabling a termination resistance of the source device on the common node upon determining by the source device that the connection with the sink device has been lost.

22. The medium of claim 20, wherein the discovery of the connection between the source device and the sink device utilizes HDMI™

(High-Definition Multimedia Interface) protocol or MHL™

(Mobile High-Definition Link) protocol.