The interface to the mXTE143E touchscreen sensor is I²C. The device also has an alert pin (~CHG), which will toggle when a touch event occurs. The I²C address of the device is 0x4A and the maximum bus clock speed is 400kHz.
The protocol that is used to communicate with the touchscreen controller as well as the datasheet of the device is only available under a NDA but these documents are not necessary to use the controller on the mXT143E Xplained because all the required code and the configuration is available in the Atmel Software Framework (ASF). If the user intends to fully evaluate the mXT143E in order to make his own maXTouch design contact the nearest Atmel sales representative to get an NDA agreement.
Application notes for maXTouch can be obtained from the Atmel website by registration.