EDID Parameters

[joe306]

Hello, looking to implement HDMI on my board. This is the first time I will be working with HDMI. Where can I get the EDID parameters to store in the support EEPROM?

Thank you

Joe

[ashokkum]

Hello @joe306 ,

The details of each parameter introduced in the EDID are clearly documented in the below link,

https://en.wikipedia.org/wiki/Extended_Display_Identification_Data 

Hope this information is helpful to you. please let me know, if you have any questions.

Cheers,

Ashok.

[joe306]

In my application I am interfacing with a camera and I want to use HDMI to display the camera video. Is there some software that will generate the EDID data and then take the data and store it in the I2C EEPROM? This is my first time with HDMI.

Thank you

[watari]

Hi @joe306 

You don't need I2C EEPROM if you implement HDMI Tx,

However, you must read and parse EDID on HDMI monitor and decide output video timing with this information.

Best regards,

[joe306]

Hello, thank you very much for responding to my message. I am looking at the ZCU106 board as a reference and see they used a little EEPROM with an I2C interface.  So, I ask on the ZCU106 board how does it read and parse the EDID? Is that done by reading a register in the SN65DP159 chip? By the way the VCK190 board has the same HDMI TX schematic as the ZCU106, the schematics for the VCK190 are easier to read (page 50).

Last, what is the purpose of the EEPROM? If I don't need it, do I see need to interface with the HDMI_CTL_SCL/SDA on the SN6a5DP159 device?

Thank you very much for your help.

Joe

[joe306]

Hello, let me run this lazy option by you. What if I only support one resolution that is most common on monitors, say 1920x1080p at 60Hz. Limits the monitors that you can connect to but still works.

Comments?

[watari]

Hi @joe306 

> So, I ask on the ZCU106 board how does it read and parse the EDID? Is that done by reading a register in the SN65DP159 chip?

Refer the following URL. You can see the reason and so on.

https://www.xilinx.com/support/documentation/boards_and_kits/zcu106/ug1244-zcu106-eval-bd.pdf#page=71

> Last, what is the purpose of the EEPROM?

As I already mentioned before, it's for ex. HDMI Rx and HDCP key.

> If I don't need it, do I see need to interface with the HDMI_CTL_SCL/SDA on the SN6a5DP159 device?

Refer the above URL.

Best regards,

[watari · Accepted solution]

Hi @joe306 

>What if I only support one resolution that is most common on monitors, say 1920x1080p at 60Hz. Limits the monitors that you can connect to but still works.

I'm a little confusing.

As you mentioned before, you implement HDMI Tx. Not HDMI Rx.

So, your design (HDMI Tx) read EDID from target monitor via DDC/CI.

And bare metal software or kernel driver recognizes supported video timing and so on by reading EDID.

Best regards,

[joe306]

Hello, thank you for responding to my message. I'm clear now.

Thank you very much, Joe