EDID (Extended Display Identification Data) is an interface between the graphics unit and the connected monitor. Via this the graphic unit receives the values of the display like timings, resolution, colors and further information about the used display. mostly the EDID data is stored as 128 byte large binary in an EEPROM which is then read via an interface like I2C.

EDID generators and editors are mostly used to create and customize EDID binaries. After the necessary values are collected from the display data sheet, they can be inserted into the tool. The edid generator creates the required binary from the entered data like resolution, standard timings and other values.

Many EDID generators can be found on the internet. We use the wxEDID editor (GPLv3) to explain the process. Creating EDID data is similar for most programs and there is no need to use the same EDID generator as in this article. the wxEDID tool can be found Here

GUI example

1. load the Bin file which should be edited: File > Open EDID Binary
2. change the values using the data sheet for the display. Information about the currently selected value is displayed in the info box below.
3. if the block DTD: Detailed Timing Descriptor is selected in the block tree, you can switch to the DTD Constructor tab at the top to set values like timing and resolution more easily and with graphical feedback regarding the display size.
4. Once all changes have been entered into the tool, the binary file can be created: File > Save EDID Binary

To change the Edid data on the populated PTN3460 chip, its firmware must be adapted. The Edid data is located at certain addresses in the firmware and therefore the old 128 bytes must be overwritten with the new created bytes.

• Firmware.bin (PTN3460)
• new EDID Binary (128 Bytes)
• Flash-Tool “PTN3460 Flash-over-AUX” (Distribution only by NXP)
• Hex file manipulation program (eg. okteta)

to change the EDID data in the chip, the created EDID data must be written into the firmware at the appropriate location:

• Open the PTN3460.bin and the created EDID.bin in a Hex Editor
• Search for the address of the Edid data in the firmware file, which should be replaced by the customized EDID data (use table –EDID addresses– below)
• Copy the 128 bytes from the created EDID file and overwrite the existing values at the correct address
• Make sure that the existing data is replaced and not inserted. The firmware binary must not contain more bytes than before!
• Save new Firmware.bin

EDID addresses

After creating the edited firmware binaries the file can be written to the LVDS bridge.
Before the tool is started, the required files must be located in the same folder as the tool.

Example (windows):

 <parent Folder>
    |--- FLASH.bin
    |--- PTN3460.bin (custom firmware binary)
    |--- AuxDLL.dll
    |--- PTN3460_FOA_App.exe

Start flash process:

1. Boot the module on which the LVDS bridge should be flashed use an operating system which is supported by the NXP tool
2. Start the Tool (PTN3460_FOA_App) and click on the button DISPLAY
3. Select the Displaybridge in the dropdown-menu (DP0 on the most modules)
4. Press the button Flash to start the flash process

As soon as the process has been completed without errors, the text “Programming complete” should appear in the info window.

1. Reboot module and stop boot sequence in BIOS
2. From BIOS front page navigate to: Device Management → SIO TQMx86
3. Enable Enable LVDS bridge and LVDS Configuration
4. Set LVDS EDID information to EDID Emulation on
5. Under LVDS Resolution select the index whose resolution was adjusted
6. Press F10 to save changes and then reboot the system

The displayed resolution is stored firmly in the BIOS and is not read from the chip. An adjustment of the LVDS resolution table requires a customer specific BIOS!

BIOS-Example