Are you using our WinCE BSP or Linux?

For our WinCE BSP, we set the interface to only be 16 bit and use a frame buffer of 5:6:5 (R:G:B), which allows for 16bpp. I'm not sure how the standard Linux offering is set up, but I assume it's the same since Logic's display kits are connected this way (16 bits).


If using 16 bit (yes, not 18), you would connect to a 24 bit display like so:


Why? -> You don't have enough bits, so this pattern will give you the most color contrast, or varied color spectrum I guess you could say. Otherwise, you could tie the lower sig bits high or low, but then you'd never be able to get all off or all on. Does this make sense?

The IMX31 does actually have 8 bits of each color and LogicPD makes these extra bits available on connector J9 on the development baseboard. So, if you wanted to write your display driver (set up the correct interface and frame buffer), you could actually use 24 bits, 1:1 with this LCD. I recommend against it unless you truly need this and want to spend the time. Note, when you go over 16bits, you go over 16bpp for a frame buffer. Anything over this and your frame buffer's pixels have to take up 24 bits or 32 bits of each 32bit word in RAM. So, the overhead becomes quite a bit more.

If you truly wanted 18 bits to 24 bits, you can see from my example above how this would be done by looking at the green bits which have 6 bits available in the 5:6:5 configuration.

This can be confusing.

Also,
A basic application note from Sharp for interfacing LCDs to microcontrollers can be found at this link:

http://document.sharpsma....445289C909836E86A350

I can't guarantee it'll always be at this link, but if you search for 'Sharp Interfacing LCD Panels to Microcontrollers' you should find it. It is more for smaller panels and microcontrollers, ARM7 and smaller, but is true for more beefy LCD controllers also. It just doesn't cover when you get 16bpp or higher, which you'll want to read up on the Processor's LCD controller section in the specification to understand how it specifically needs to be programmed.

Thanks,
-Mike