Can STM32F7x9 MCU's MIPI-DSI support up to 1280 x 800 resolution with at least 18 bit color?

[Donny Chiu]

We are planning to use STM32F7x9 to drive a 1280x800 TFT LCD panel via MIPI-DSI interface. But according to the datasheet, seems it only support up to 1280x720 or 720p resolution. Can it support 1280x800 resolution? We also need to support at least 18bit color, with RGB666 format I supposed. Also would like to have an idea how many fps it can support.

[Tesla DeLorean]

Can't you just do the math based on the bit rate of the two available DSI channels?​

That should at least define a ceiling.

Then look at the clocking combinations that fit the LTDC and DSI.

Not sure 18 bit is an option, might have to choose between 16 or 24 bits modes.​

[Tesla DeLorean]

The amount of external memory and the speed of the memory will also be constraining.​ As your bandwidth requirements are quite high, you'll want a 32 bit wide data bus.

[Donny Chiu]

Thanks.

I did a little math, for DSI:

Horizontal * Vertical * Refresh Rate * Pixel Size / Number of Data Lane / 2 (bit per clock)

All I need is 15fps and 18bit color so:

= 1280 * 800 * 15 * 18 / 4 / 2

= 34,560,000Hz

According to the spec. the PLL can output up to 1000MHz.

So, I thought there is more than enough.

But the first page of the spec. is saying it can only support up to 720p 30Hz.

So, I am thinking there must be something wrong with my calculation.

And I want to check what I did wrong or misinterpreted.