Every qualified event detected by the CPT112S capacitive sensing input engine generates a single 4-byte packet that can be retrieved by the host processor over the event buffer I2C interface, the event packet is transmitted MSB first.
The device's I2C slave address is configurable through the configuration profile, by default, the address is 0xE0. The device will ACK its slave address only when the interrupt pin is low, signalling that a packet is ready to be read by the host. If the interrupt pin is logic high, the device will not ACK its slave address.
Here is a full feature comparison table for all TouchXpress devices.