Q:

I want to communicate with two different devices at two different voltage levels, one at 3.3 V and one at 2 V. Can connect the IOVDD_x pins to different supply voltages to achieve this without using level shifters?

A:

No, all of the power supply pins to the EFM32 must be supplied with the same voltage level, which means that all GPIO pins will operate at the same level as well. This level can be between 1.8 V and 3.8 V. For inputs the GPIO pins can tolerate up to VDD+0.3V.