Using DPI Display with MIPI DSI Bridge

[DudeTriesCompute]

Hello dear ESP32-Community,

I am quite new to hardware design with the ESP32, and I’m currently planning my first project using the new ESP32-P4. My goal is to use a display with a parallel interface, such as the ILI6122, and connect it to the ESP32-P4’s DSI interface. While researching, I noticed that many Raspberry Pi DSI displays use undocumented interface ICs. On some boards, I discovered an IC called the ICN6211, which functions as a parallel-to-DSI bridge.

At this stage, I have not written any software yet and am mainly trying to figure out if my idea is possible before I design my own PCB. My programming experience with ESP-IDF is very limited, but I am eager to learn.

Here are my main questions:

Is it even possible to use a bridge IC like the ICN6211 with the ESP32-P4’s DSI interface to connect a parallel display?

If it is possible, which features might I have to give up compared to a native DSI display?

What would the implementation look like in code? Are there any example projects or libraries for this setup?

After implementing the bridge, can I use the display just like a native DSI display, or are there significant differences in functionality or performance?

If this setup is not possible or practical, are there good, affordable alternatives to bulky native DSI displays?

Has anyone in the community already gained experience with such bridge ICs and the ESP32-P4?

Any advice, schematic examples, or code snippets would be greatly appreciated. Thank you in advance for your help!

[Sprite]

Unless you can't spare the GPIOs, there's not really any need: the LCD peripheral in the P4 can output parallel data all by itself.

[DudeTriesCompute]

Unless you can't spare the GPIOs, there's not really any need: the LCD peripheral in the P4 can output parallel data all by itself.

Hello thank you for your reply. In my project, I use quite a lot of hardware components. Among other things, I'm utilizing I2S, I2C bus, SPI, SDIO interfaces and many sensors. Therefore, it's almost impossible for me to allocate 20 pins or more for a parallel display.

[Demirug]

Unless you can't spare the GPIOs, there's not really any need: the LCD peripheral in the P4 can output parallel data all by itself.

Sorry for hijacking.

We successfully using the P4 LCD peripheral for a project that is currently in the prototype phase. But for an upcoming project we need a much higher pixel clock.(resolution)- Based on the limited documentation I have for the P4 the LCD peripheral  is limited to 40MHz while the Mipi DSI has 2 1.5 Gbps lanes. Is this still correct?

[Sprite]

Based on the limited documentation I have for the P4 the LCD peripheral  is limited to 40MHz while the Mipi DSI has 2 1.5 Gbps lanes. Is this still correct?

No, it is not. The P4 LCD peripheral can be clocked from the 160MHz PLL (or alternatively the APLL) so the max clock frequency is a lot higher.

[Demirug]

Based on the limited documentation I have for the P4 the LCD peripheral  is limited to 40MHz while the Mipi DSI has 2 1.5 Gbps lanes. Is this still correct?

No, it is not. The P4 LCD peripheral can be clocked from the 160MHz PLL (or alternatively the APLL) so the max clock frequency is a lot higher.

Thank you for this information. It's very helpful to know.

[Demirug]

Sorry to bring this up again:

The just droped V 0.1 of the technical reference still has the 40 and 80 MHz limits.

Notes:
No matter in which format, RGB or I8080/MOTO6800, the rules below must be followed when accessing
internal and external memory via GDMA:
• If LCD data bus is configured to 8-bit parallel output mode, then
– The pixel clock frequency must be less than 80 MHz.
– If YUV-RGB format conversion is being used at the same time, the pixel clock frequency must be
less than 60 MHz.
• If LCD data bus is configured to 16-bit parallel output mode, then
– The pixel clock frequency must be less than 40 MHz.
– If YUV-RGB format conversion is being used at the same time, the pixel clock frequency must be
less than 30 MHz.

I kind of assume that this section has not been updated as it also does not include the 24 bit mode?

[eriksl]

You can't use SPI for your display connection?

[yasirkq]

Hello dear ESP32-Community,

I am quite new to hardware design with the ESP32, and I’m currently planning my first project using the new ESP32-P4. My goal is to use a display with a parallel interface, such as the ILI6122, and connect it to the ESP32-P4’s DSI interface. While researching, I noticed that many Raspberry Pi DSI displays use undocumented interface ICs. On some boards, I discovered an IC called the ICN6211, which functions as a parallel-to-DSI bridge.

At this stage, I have not written any software yet and am mainly trying to figure out if my idea is possible before I design my own PCB. My programming experience with ESP-IDF is very limited, but I am eager to learn.

Here are my main questions:

Is it even possible to use a bridge IC like the ICN6211 with the ESP32-P4’s DSI interface to connect a parallel display?

If it is possible, which features might I have to give up compared to a native DSI display?

What would the implementation look like in code? Are there any example projects or libraries for this setup?

After implementing the bridge, can I use the display just like a native DSI display, or are there significant differences in functionality or performance?

If this setup is not possible or practical, are there good, affordable alternatives to bulky native DSI displays?

Has anyone in the community already gained experience with such bridge ICs and the ESP32-P4?

Any advice, schematic examples, or code snippets would be greatly appreciated. Thank you in advance for your help!

I found this library at ESP component registry website which may work for you.
https://components.espressif.com/compon ... 0.6/readme
Some of the displays mentioned in this library have used ICN6211 bridge controller.

I have not personally tested yet since I am already struggling to get it work with other display like RPi touch display v2 and Luckfox's 5 inch 800x480 display which also uses icn6211.

[yasirkq]

If you're seeking robust DPI/DSI support for ESP32-P4, I've developed a dedicated GitHub repository to streamline integration with various DSI displays.
Explore it here: https://github.com/embenix/ESP32P4-DSI-Support-Hub

The project is actively under development, with ongoing additions for new display vendors as I acquire them—contributions welcome!