UART/Serial VOLTAGE of Atmega328p SMD

Just made a PCB with SIM900A and Atmega328P SMD and before I turn it on,I would like to make sure that voltage levels match,I'll be powering microcontroller from 4365mV (4.36v).So what's voltage level of TX and RX?

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So,If I power it from 3v3 serial voltage should be 3.3v? right?

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