topic Driving a MIP Memory-In-Pixel display in LPC Microcontrollers

Driving a MIP Memory-In-Pixel display

paolog — Wed, 01 Dec 2021 11:38:27 GMT

Hi everyone.

For a new project we're considering a MIP display with 8 bits bus, but RGB222 format (64 colors, 6bpp), where the first 2 bits are discarded and the rest of the byte are RRGGBB.

I've been browsing the LPC microcontrollers with LCD driver, but looking at the LPC546xx Series I found there's no direct drive for this format. Is there a format that would allow me to use the RGB222? Maybe in another family?

What about the GUI Guider? Is it able to manage this color configuration?

Re: Driving a MIP Memory-In-Pixel display

ZhangJennie — Fri, 03 Dec 2021 09:47:44 GMT

You are right.

This states in UM.

TFT panels only support one or more of the following color modes:
• 1 bpp, palettized, 2 colors selected from available colors.
• 2 bpp, palettized, 4 colors selected from available colors.
• 4 bpp, palettized, 16 colors selected from available colors.
• 8 bpp, palettized, 256 colors selected from available colors.
• 12 bpp, direct 4:4:4 RGB.
• 16 bpp, direct 5:5:5 RGB, with 1 bpp not normally used. This pixel is still output, and
can be used as a brightness bit to connect to the Least Significant Bit (LSB) of RGB
components of a 6:6:6 TFT panel.
• 16 bpp, direct 5:6:5 RGB.
• 24 bpp, direct 8:8:8 RGB, providing over 16 million colors.
Each 16-bit palette entry is composed of 5 bpp (RGB), plus a common intensity bit. This provides better memory utilization and performance compared with a full 6 bpp structure.
The total number of colors supported can be doubled from 32K to 64K if the intensity bit is used and applied to all three color components simultaneously.
Alternatively, the 16 signals can be used to drive a 5:6:5 panel with the extra bit only
applied to the green channel.

Have a nice day,

Jun Zhang

Re: Driving a MIP Memory-In-Pixel display

paolog — Mon, 06 Dec 2021 15:58:54 GMT

Thank you for your post. Unfortunately I couldn't find replies to my questions.

1. Is it possible for an MCU in LPC546xx Series (or another family) to drive a parallel RGB222 lcd?

2. Is GUI Guider able to manage an RGB222 display?

Thank you,

Paolo

Re: Driving a MIP Memory-In-Pixel display

ZhangJennie — Tue, 07 Dec 2021 09:44:18 GMT

Paolo

To drive a parallel RGB222 lcd, normally we need several spare IOs and very fast coprocessor to handle LCD . while LPC546xx only has one core, thus it makes parallel lcd very slow. I mean it's possible but we can't guarantee the refreshing speed. That's why we don't have any reference design for this. We recommend LPC546xx supported RGB format as I listed in my previous reply.

GUI Guider is a graphical user interface development tool, for example convert a picture to code. it's not for low level driver developing. It can manage RGB222 display but your problem is lack of driver support.

Thanks

Jun Zhang

Re: Driving a MIP Memory-In-Pixel display

paolog — Fri, 10 Dec 2021 10:33:55 GMT

Thank you for the explanation.

Unfortunately we already selected the LCD and we can't change the RGB format. We'll look for a different solution, then.

Best regards,

Paolo

Re: Driving a MIP Memory-In-Pixel display

ZhangJennie — Mon, 13 Dec 2021 05:18:59 GMT

You are welcome.