Determining a pre skew and post skew calibration data rate in a mobile display digital interface (MDDI) communication system

• US 8,650,304 B2
• Filed: 04/14/2005
• Issued: 02/11/2014
• Est. Priority Date: 06/04/2004
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Anderson, Jon James, Steele, Brian, Wiley, George Alan, Shekhar, Shashank
• Primary Examiner(s): Winder, Patrice
• Assistant Examiner(s): Chang, Julian
• Application Number:
  US11/107,536
• Publication Number:
  US 20060034326A1
• Time in Patent Office: 3,225 Days
• Field of Search: 709227-229, 709/250, 710/8, 710/10, 710 33- 35, 710/58, 710/60
• US Class Current: 709/227
• CPC Class Codes: H04L 69/18 Multiprotocol handlers, e.g. single devices capable of handling multiple protocols
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04M 1/72409 by interfacing with external accessories hands-free H04M1/60
• CPC Class Codes: H04M 1/72412 using two-way short-range wireless interfaces
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A data interface for transferring digital data between a host and a client over a communication path using packet structures linked together to form a communication protocol for communicating a pre-selected set of digital control and presentation data. The signal protocol is used by link controllers configured to generate, transmit, and receive packets forming the communications protocol, and to form digital data into one or more types of data packets, with at least one residing in the host device and being coupled to the client through the communications path. A maximum operating data rate can be negotiated. The interface provides a cost-effective, low power, bi-directional, high speed data transfer mechanism over a short-range “serial” type data link, which lends itself to implementation with miniature connectors with thin flexible cables which are especially useful in connecting display elements such as wearable micro-displays to portable computers and wireless, communication devices.

Claims

1. A method of determining a data rate for a communication link between a host and a client in a mobile display digital interface system, the method comprising:

selecting, by the host, a first data rate at which to operate the communication link, the first data rate being within a minimum data rate range or a preselected minimum rate;

requesting a client capability packet by the host from the client;

receiving by the host the client capability packet comprising a pre-calibration data rate capability field having a first value specifying a maximum data rate at which the client can operate prior to performing forward link skew calibration and a post-calibration data rate capability field having a second value specifying a maximum data rate at which the client can operate after performing forward link skew calibration;

selecting by the host a second data rate at which to operate the communication link, the second data rate being equal to or less than the first value of the pre-calibration data rate capability field;

sending by the host a forward link skew calibration packet to the client if the client capability packet indicates that the client is capable of responding to a forward link skew calibration packet, the forward link skew calibration packet including a calibration data sequence allowing the client to perform a forward link skew calibration during a duration of the calibration data sequence; and

selecting, by the host, after sending the forward link skew calibration packet, a third data rate at which to operate the communication link, the third data rate being less than or equal to the second value of the post-calibration data rate capability field.

2. The method of claim 1, wherein the minimum data rate range is from 0.001 megabit per second to 1 megabit per second.

3. The method of claim 1, wherein the client capability packet includes a bit having a value indicating whether the client is capable of responding to a forward link skew calibration packet.

4. The method of claim 1, wherein requesting a client capability packet by the host from the client comprises:

setting, by the host, a flag in a reverse link encapsulation packet to request the client to send the client capability packet to the host;

providing by the host a reverse data packets field within the reverse link encapsulation packet, the reverse data packets field having a duration; and

sending the reverse link encapsulation packet from the host to the client over the communication link, the reverse link encapsulation packet allowing the client to take control of the communication link and send packets to the host over the communication link during the duration of the reverse data packets field.

5. A system for determining a data rate for a communication link between a host and a client in a mobile display digital interface system, the system comprising:

means for selecting, by the host, a first data rate at which to operate the communication link, the first data rate being within a minimum data rate range or a preselected minimum rate;

means for requesting a client capability packet by the host from the client;

means for receiving by the host the client capability packet comprising a pre-calibration data rate capability field having a first value specifying a maximum data rate at which the client can operate prior to performing forward link skew calibration and a post-calibration data rate capability field having a second value specifying a maximum data rate at which the client can operate after performing forward link skew calibration;

means for selecting by the host a second data rate at which to operate the communication link, the second data rate being equal to or less than the first value of the pre-calibration data rate capability field;

means for sending by the host a forward link skew calibration packet to the client if the client capability packet indicates that the client is capable of responding to a forward link skew calibration packet, the forward link skew calibration packet including a calibration data sequence allowing the client to perform a forward link skew calibration during a duration of the calibration data sequence; and

means for selecting, by the host, after sending the forward link skew calibration packet, a third data rate at which to operate the communication link, the third data rate being less than or equal to the second value of the post-calibration data rate capability field.

6. The system of claim 5, wherein the minimum data rate range is from 0.001 megabit per second to 1 megabit per second.

7. The system of claim 5, wherein the client capability packet includes a bit having a value indicating whether the client is capable of responding to a forward link skew calibration packet.

8. The system of claim 5, wherein the means for requesting a client capability packet by the host from the client comprises:

means for setting, by the host, a flag in a reverse link encapsulation packet to request the client to send the client capability packet to the host;

means for providing by the host a reverse data packets field within the reverse link encapsulation packet, the reverse data packets field having a duration; and

means for sending the reverse link encapsulation packet from the host to the client over the communication link, the reverse link encapsulation packet allowing the client to take control of the communication link and send packets to the host over the communication link during the duration of the reverse data packets field.

9. A computer program product, comprising:

a non-transitory computer-readable medium comprising program code for determining a data rate for a communication link between a host and a client in a mobile display digital interface system, the program code comprising program instructions that, when executed by a processor, cause the processor to perform operations comprising;

selecting, by the host, a first data rate at which to operate the communication link, the first data rate being within a minimum data rate range or a preselected minimum rate;

requesting a client capability packet by the host from the client;

receiving by the host the client capability packet comprising a pre-calibration data rate capability field having a first value specifying a maximum data rate at which the client can operate prior to performing forward link skew calibration and a post-calibration data rate capability field having a second value specifying a maximum data rate at which the client can operate after performing forward link skew calibration;

selecting by the host a second data rate at which to operate the communication link, the second data rate being equal to or less than the first value of the pre-calibration data rate capability field;

sending by the host a forward link skew calibration packet to the client if the client capability packet indicates that the client is capable of responding to a forward link skew calibration packet, the forward link skew calibration packet including a calibration data sequence allowing the client to perform a forward link skew calibration during a duration of the calibration data sequence; and

selecting, by the host, after sending the forward link skew calibration packet, a third data rate at which to operate the communication link, the third data rate being less than or equal to the second value of the post-calibration data rate capability field.

10. The computer program product of claim 9, wherein the minimum data rate range is from 0.001 megabit per second to 1 megabit per second.

11. The computer program product of claim 9, wherein the client capability packet includes a bit having a value indicating whether the client is capable of responding to a forward link skew calibration packet.

12. The computer program product of claim 9, wherein the program instructions that cause the processor to perform the operation of requesting a client capability packet by the host from the client comprise program instructions that, when executed by the processor, cause the processor to perform operations comprising:

setting, by the host, a flag in a reverse link encapsulation packet to request the client to send the client capability packet to the host;

providing by the host a reverse data packets field within the reverse link encapsulation packet, the reverse data packets field having a duration; and

sending the reverse link encapsulation packet from the host to the client over the communication link, the reverse link encapsulation packet allowing the client to take control of the communication link and send packets to the host over the communication link during the duration of the reverse data packets field.