iMX 93 MIPI-DPI-2 Pin mapping

[fdeininger]

Dear NXP-Team,
we are using the i.MX93 processor on our hardware to operate, among other things, a parallel display. The connection was designed to support an 18‑bit configuration. We would now like to operate a display with a 24‑bit configuration using the same hardware. According to the reference manual, however, the color mapping appears to be fundamentally different (see attached image).

Therefore, I would like to ask the following questions in general:

1. Is it possible to switch between 18‑bit and 24‑bit in such a way that the MSBs align? In other words, can the display be fully utilized in both modes, with identical hardware?

2. If it is possible, how can this be achieved?

3. If it is not possible, is there a reason why the color mapping has been designed this way?
   
   Best regards,
   Felix D.
   
   

[db16122]

It seems there are 2 modes for 18bit setup. The config 2 may compatible with 24 bit setup with 6 pin addtional.

Which mode the 18bit setup originally used?

[fdeininger]

Hello

We are using the 18‑bit configuration 1. Although configuration 2 appears more suitable at first glance, this is not the case in practice. Since the most significant bits (R[5] in 18‑bit mode and R[7] in 24‑bit mode) do not align, this results in a 2‑bit offset for each signal position in our use case. Consequently, when switching between the modes, at least one of the configurations would not be able to utilize the two MSBs of each color channel, which has a significant impact on the LCD output quality.

[AldoG · Accepted solution]

Hello,

No, it is not possible as you can see i.MX93 defines different pin assignments for RGB888 and RGB666.

The reason may vary as I'm not 100% certain of the decission for this, but this reduce unnecessary pins in 18‑bit mode, and usually older LCD modules expected RGB666 on specific positions so this could be a way to mantain compatibility.

Best regards/Saludos,
Aldo.

[fdeininger]

Thank you for the quick response. I was afraid this might be the case. Thank you for clarifying.