PACKET-BASED DIGITAL DISPLAY INTERFACE SIGNAL MAPPING TO MICRO SERIAL INTERFACE

• US 20110191480A1
• Filed: 08/24/2010
• Published: 08/04/2011
• Est. Priority Date: 02/03/2010
• Status: Active Grant

• Current Assignee: STMicroelectronics Incorporated (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Incorporated (STMicroelectronics NV)
• Inventors: Kobayashi, Osamu
• Granted Patent: US 8,578,031 B2
• Time in Patent Office: Days
• US Class Current: 709/227
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: G06F 1/266 Arrangements to supply power to external peripherals either directly from the computer or under computer control, e.g. supply of power through the communication port, computer controlled power-strips
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3209 Monitoring remote activity, e.g. over telephone lines or network connections
• CPC Class Codes: G06F 13/102 where the programme performs an interfacing function, e.g. device driver G06F13/105 takes precedence; scheduling within device drivers G06F9/52; contention policies within device drivers G06F9/4881
• CPC Class Codes: G06F 13/4081 Live connection to bus, e.g. hot-plugging current or voltage limitation during live insertion H02H9/004
• CPC Class Codes: G06F 13/4269 using a handshaking protocol, e.g. Centronics connection
• CPC Class Codes: H01R 11/00 Individual connecting elements providing two or more spaced connecting locations for conductive members which are, or may be, thereby interconnected, e.g. end pieces for wires or cables supported by the wire or cable and having means for facilitating electrical connection to some other wire, terminal, or conductive member, blocks of binding posts
• CPC Class Codes: H04N 21/4122 additional display device, e.g. video projector digital output for controlling a plurality of local displays G06F3/1423
• CPC Class Codes: H04N 21/43632 involving a wired protocol, e.g. IEEE 1394 high-speed IEEE 1394 serial bus H04L12/40052
• CPC Class Codes: H04N 7/173 with two-way working, e.g. subscriber sending a programme selection signal

Abstract

A passive cable adaptor for connecting a data source device with a display device is described. The adaptor has a packet-based interface connector at one end, the connector having a positive main link pin, a negative main link pin, a positive auxiliary channel pin, and a negative auxiliary channel pin. At the other end is a micro serial interface connector, wherein multimedia content is transmitted over the cable adaptor and electrical power is supplied over the cable adaptor simultaneously. The cable adaptor has an auxiliary and hot plug detect (HPD) controller utilized to map the auxiliary channel and HPD signals of the packet-based digital display to the micro serial interface ID signal.

Claims

1. A method of enabling the transmission of data and the supplying of power between a multimedia data source device and an external display device, the method comprising:

mapping main link signals of a packet-based interface to a micro serial interface differential pair;

mapping auxiliary channel signals to a micro serial interface ID pin;

mapping a hot plug detect (HPD) signal of the packet-based interface to the micro serial interface ID pin, wherein said mappings enable transport of a multimedia data stream from the data source device to the external display device; and

enabling the supply of power from the external display device to the source device using a micro serial interface connection while simultaneously transporting the multimedia data stream.

2. A method as recited in claim 1 further comprising:

mapping a ground signal of the data source device to a packet-based display interface ground signal.

3. A method as recited in claim 1 wherein mapping main link signals to a micro serial interface differential pair further comprises:

mapping a positive main link signal to a positive differential signal (D+); and

mapping a negative main link signal to a negative differential signal (D−

).

4. A method as recited in claim 1 wherein mapping auxiliary channel signal to the ID pin further comprises:

mapping an auxiliary channel positive signal to a first differential I/O signal; and

mapping an auxiliary channel negative signal to a second differential I/O signal.

5. A method as recited in claim 1 further comprising:

completing sideband communications before main link transmissions of multimedia content begins.

6. A method as recited in claim 5 wherein sideband communications are conducted over auxiliary channel signals.

7. A method as recited in claim 1 wherein power is supplied over a packet-based interface power pin to a Vbus pin.

8. A method as recited in claim 1 wherein the source is a smart phone having a micro serial interface connector and the external display device is a television having a packet-based digital display interface connector.

9. A method as recited in claim 1 further comprising:

performing an auxiliary channel handshake for discovering whether a high-voltage external display device is present.

10. A method as recited in claim 1 wherein mapping HPD signal and mapping auxiliary channel signals further comprise utilizing an auxiliary/HPD controller.

11. A method as recited in claim 10 further comprising:

converting between a single-ended auxiliary channel signal and differential auxiliary channel signal on the external display device.

12. A method as recited in claim 10 further comprising:

forwarding the HPD signal from the auxiliary/HPD controller as soon as an auxiliary reply transaction is completed.

13. A method as recited in claim 10 further comprising:

maintaining an output portion of the micro serial interface ID pin tri-stated.

14. A cable adaptor for connecting a data source device with a display device, the cable adaptor comprising:

a packet-based interface connector at a first end having a positive main link pin, a negative main link pin, a positive auxiliary channel pin, and a negative auxiliary channel pin;

an auxiliary and HPD controller having a specific number of signals; and

a micro serial interface connector at a second end, wherein multimedia content is transmitted over the cable adaptor and electrical power is supplied over the cable adaptor simultaneously.

15. A cable adaptor as recited in claim 14 wherein the packet-based interface connector further comprises:

a pin for hot plug detect (HPD) signals.

16. A cable adaptor as recited in claim 14 wherein the main link positive signal is mapped to a positive differential signal (D+) and the main link negative signal is mapped to a negative differential signal (D−

).

17. A cable adaptor as recited in claim 14 wherein the auxiliary and HPD controller has two differential input/output signals, an ID signal, and an HPD signal.

18. A cable adaptor as recited in claim 14 further comprising A/C-coupling caps.

19. A cable adaptor as recited in claim 14 further comprising a differential re-driver.

20. A cable adaptor as recited in claim 14 further comprising a bi-directional passive switch.

21. A cable adaptor as recited in claim 14 further comprising a power-to-Vbus regulator component.

22. A method of transmitting data and supplying power between a multimedia device and a display device using a cable adaptor having a micro serial interface connector and a packet-based digital display interface, the method comprising:

enabling the supply of power from the display device to the multimedia device using a Vbus pin and a packet-based digital interface power pin; and

performing a mapping between packet-based digital interface signals and micro serial interface signals, wherein a portion of the mapping is implemented by an auxiliary/hot plug detect (HPD) controller.

23. A method as recited in claim 22 wherein power is supplied while the multimedia data is being transmitted from the multimedia device to the display device.

24. A method as recited in claim 22 wherein the auxiliary/HPD controller maps a positive auxiliary channel signal to a first differential I/O signal and maps a negative auxiliary channel signal to a second differential I/O signal.

25. A method as recited in claim 22 further comprising:

completing sideband communications before main link transmission of multimedia content begins.

26. A multimedia data source device, comprising:

power level determination circuitry for negotiating a power level to be received from an external display device into the multimedia data source device to enable operation of the multimedia data source device at a negotiated power level;

a multimedia data processor suitable for providing multimedia data and operating using the negotiated power from the external display device; and

an interface system suitable for coupling with the external display device, the system including

a main data link suitable for transmitting multimedia data between the multimedia data source device and the external display device,

a power connector suitable for receiving the negotiated power from the external display device connected with the source device, and

an auxiliary channel suitable for transmitting sideband data between the external display device and the source device to include power negotiation messages.

27. The multimedia data source device recited in claim 26 wherein the interface system comprises a micro serial interface connector.

28. The multimedia data source device recited in claim 26 wherein the power determination circuitry enables the source device to obtain from the external display device information concerning power levels supported by the external display device.

29. The multimedia data source device recited in claim 28 wherein the power determination circuitry enables the source device to

compare power levels supported by the external display device with operating power levels supported by the source device;

and

negotiate a power level for use that is one of;

a power level supported by both the external display device and by the multimedia data source device, or

a power level supplied by a local battery of the multimedia data source device.

30. The multimedia data source device recited in claim 29 wherein information concerning the operating power levels supported by the source device is stored in a memory of the source device.

31. The multimedia data source device recited in claim 29 wherein information concerning the operating power levels supported by the source device is contains priority information enabling the source to negotiate a power level in accordance with a priority scheme.

32. The multimedia data source device recited in claim 27 wherein the source device is a smart phone having a micro serial interface connector.

33. The multimedia data source device recited in claim 26 wherein the interface system includes circuitry that enables the performing of an auxiliary channel handshake for discovering whether an external display device capable of providing varying levels of power is present.

34. The multimedia data source device recited in claim 28 wherein the power determination circuitry of the source device to enable,

determining current levels supplied by various voltage levels supported by the external display device;

and

negotiate a current level to be received by the source device such that the current level is one of;

a current level supported by both the external display device and by the multimedia data source device, or

a current level supplied by a local battery of the multimedia data source device.

35. A method of enabling the transmission of a negotiated power from a display device to a connected multimedia data source device, the method comprising:

establishing a connection between a multimedia data source device and an external display device, the connection comprising a power connection and an auxiliary data connection;

negotiating a power level for power transmission from the external display device to the multimedia data source device to enable operation of the multimedia data source; and

supplying the negotiated power from the external display device to the source device.

36. The method recited in claim 35 wherein

establishing the connection further includes establishing a connection that includes a main link data connection suitable for transporting a multimedia data stream;

and

supplying the negotiating power includes supplying the power using a power connector of a micro serial interface connection while simultaneously transporting the multimedia data stream through the main link data connection.

37. The method recited in claim 35 wherein

establishing the connection includes establishing a micro serial interface connection that includes a main link data connection suitable for transporting packetized multimedia data;

and

supplying the negotiating power includes supplying the power using a power connector of the micro serial interface connection while simultaneously transporting the packetized multimedia data through the main link data connection.

38. The method recited in claim 35 wherein negotiating the power level for power transmission from the external display device to the multimedia data source device comprises

obtaining, from the external display device, information concerning power levels supported by the external display device;

comparing those power levels with operating power levels supported by the multimedia data source device; and

electing a negotiated power level that is one of;

a power level supported by both the external display device and by the multimedia data source device, or

a power level supplied by a local battery of the multimedia data source device.

39. The method recited in claim 38 wherein operating power levels supported by the multimedia data source device are ranked in a priority such that said electing of the negotiated power level includes selecting a power level having a highest priority as the negotiated power level.

40. The method recited in claim 38 wherein the information concerning power levels supported by the external display device is stored in memory registers of the external display device;

and

information concerning operating power levels supported by the multimedia data source device is stored in memory registers of the multimedia data source device.

41. The method recited in claim 36 wherein the negotiated power is supplied over a packet-based interface power pin to a Vbus pin.

42. The method recited in claim 36 wherein the source device is a smart phone having a micro serial interface connector and the external display device is a television having a packet-based digital display interface connector.

43. The method recited in claim 36 further comprising:

performing an auxiliary channel handshake for discovering whether an external display device capable of providing varying levels of power is present.

44. The method recited in claim 36 wherein the method is implemented by an integrated circuit device configured to enable communication between the source device and the display device, the method embodied on a tangible computer readable media such that the method operations are executed as computer executed instructions.

45. The method of claim 44 wherein the computer executed instructions are implemented as firmware on the integrated circuit.