The TFT-LCD have a resistive Touch Scren associated.
For the TFT-035-3, a separated 4 pins connector provides the 4 signals:
For the TFT-043-3, the 4 signals are available on the TFT 40 pins connector
Those signals are connected to a Touch Screen Controller: TSC2013-Q1PW from ti, connected with an i2c interface to the FPGA.
i2c address is : 1001 000 R/nW
For the module TFT-M043-4, the Touch Screen is managed by a Touch Screen controller XPT2046 avaialable on the module. It's interface is through an SPI interface:
A 2MHz TPClk for SPI can be used.