How to use the touch panel without existing libraries

Hi Community,

I have a 3.5" TFT LCD for arduino uno with touch panel. I have seen, there are a lot of libraries and functions availabel to use it in the arduino environment. But I want it to use with a foreign MCU. There are the pins for the LCD Driver (data 8bit parallel + control), for the SD card and the power. But I couldn´t see the pins for the touch panel. Seems they are muliplext.

I want to know, to get an access to the touch panel pins.


Thank you very much for responds.
Greetings
Henry