EDID pass through via serial channel

• US 20070242062A1
• Filed: 04/18/2006
• Published: 10/18/2007
• Est. Priority Date: 04/18/2006
• Status: Abandoned Application

• Current Assignee: OWLink Technology, Inc.
• Original Assignee: OWLink Technology, Inc.
• Inventors: Guo, Yong, Xu, Mingcheng, Tzeng, Shing-Wu
• Application Number:
  US11/406,875
• Publication Number:
  US 20070242062A1
• Time in Patent Office: Days
• US Class Current: 345/204
• CPC Class Codes: G06F 3/14 Digital output to display device ; Cooperation and interconnection of the display device with other functional units
• CPC Class Codes: G09G 2340/02 Handling of images in compressed format, e.g. JPEG, MPEG
• CPC Class Codes: G09G 5/008 Clock recovery

Abstract

Techniques are disclosed for passing Extended Display Identification Data (EDID) or Enhanced-EDID (E-EDID) in an uncompressed multimedia communication system including a video sink side communicatively coupled to a video source side. An EDID AVAILABLE packet is communicated via a serial backward channel from the video sink side. A REQUEST is communicated to the video sink side via a serial forward channel to indicate the video sink side can send the EDID data. The EDID data is then communicated to the video sink side via the serial backward channel.

Claims

1. A method for passing Extended Display Identification Data (EDID) or Enhanced-EDID (E-EDID) in an uncompressed multimedia communication system including a video sink side communicatively coupled to a video source side, the method comprising:

reading EDID data at the video sink side;

in response to successfully reading the EDID data, sending an EDID AVAILABLE packet via a serial backward channel to the video source side;

receiving from the video source side a REQUEST via a serial forward channel to indicate the video sink side can send the EDID data; and

sending the EDID data to the video source side via the serial backward channel.

2. The method of claim 1 further comprising:

monitoring a hot plug detect (HPD) signal of the video sink side;

wherein reading the EDID data from the video sink side is performed in response to detecting a transition of the HPD signal to its active state.

3. The method of claim 1 wherein the REQUEST is received from the video source side in a REQUEST packet via a control field in the serial forward channel.

4. The method of claim 1 wherein sending the EDID data to the video source side via the serial backward channel further comprises:

segmenting the EDID data into EDID packets; and

sending the EDID packets to the video source side via the serial backward channel.

5. The method of claim 1 wherein the EDID data is checked for errors at the video source side, the method further comprising:

in response to errors being detected at the video source side, receiving from the video source side a repeat REQUEST via the serial forward channel to indicate the video sink side can re-send the EDID data.

6. The method of claim 1 wherein an HPD signal of the video source side is held at its inactive level to prevent EDID data reading at the video source side until the EDID data has been successfully received.

7. The method of claim 1 wherein if the HPD signal of the video sink side transitions to its inactive state, the method further comprises:

sending a status of the HPD signal to the video source side via the serial backward channel, thereby causing the video source side to transition its HPD signal to an inactive state.

8. An uncompressed multimedia communication system for passing Extended Display Identification Data (EDID) or Enhanced-EDID (E-EDID) from a video sink side to a video source side, the system comprising:

a video sink side asymmetric serial multimedia interface (ASMI) configured for reading EDID data at the video sink side, and in response to successfully reading the EDID data, sending an EDID AVAILABLE packet via a serial backward channel to the video source side;

a video source side ASMI sending to the video source side a REQUEST via a serial forward channel to indicate the video sink side can send the EDID data, and receiving the EDID data from the video sink side via the serial backward channel.

9. The system of claim 8 wherein the video sink side ASMI is further configured for monitoring a hot plug detect (HPD) signal of the video sink side, and reads the EDID data in response to detecting a transition of the HPD signal to its active state.

10. The system of claim 8 wherein the video source side ASMI sends the REQUEST in a REQUEST packet via a control field in the serial forward channel.

11. The system of claim 8 wherein the video sink side ASMI is further configured for sending the EDID data to the video source side ASMI via the serial backward channel by segmenting the EDID data into EDID packets, and sending the EDID packets to the video source side via the serial backward channel.

12. The system of claim 8 wherein the video source side ASMI is further configured for checking the EDID data for errors, and in response to detecting errors, the video source side ASMI sends a repeat REQUEST via the serial forward channel to indicate the video sink side ASMI can re-send the EDID data.

13. The system of claim 8 wherein an HPD signal of the video source side ASMI is held at its inactive level to prevent EDID data reading at the video source side ASMI until the EDID data has been successfully received.

14. The system of claim 8 wherein if the HPD signal of the video sink side transitions to its inactive state, the video sink side ASMI is further configured for sending a status of the HPD signal to the video source side ASMI via the serial backward channel, thereby causing the video source side ASMI to transition its HPD signal to an inactive state.

15. A method for passing Extended Display Identification Data (EDID) or Enhanced-EDID (E-EDID) in an uncompressed multimedia communication system including a video sink side communicatively coupled to a video source side, the method comprising:

receiving an EDID AVAILABLE packet via a serial backward channel from the video sink side;

sending to the video sink side a REQUEST via a serial forward channel to indicate the video sink side can send the EDID data; and

receiving the EDID data from the video sink side via the serial backward channel.

16. The method of claim 15 wherein the REQUEST is sent to the video sink side in a REQUEST packet via a control field in the serial forward channel.

17. The method of claim 15 wherein the EDID data received via the serial backward channel is in packet form.

18. The method of claim 15 further comprising:

checking the received EDID data for errors; and

in response to detecting errors, sending to the video sink side a repeat REQUEST via the serial forward channel to indicate the video sink side can re-send the EDID data.

19. The method of claim 15 further comprising holding an HPD signal of the video source side at its inactive level to prevent EDID data reading at the video source side until the EDID data has been successfully received.

20. The method of claim 15 wherein if the HPD signal of the video sink side transitions to its inactive state, the method further comprises:

receiving a status of the HPD signal via the serial backward channel, thereby causing the video source side to transition its HPD signal to an inactive state.