5V Tolerant GPIO pins (STM32F030K6T6)

[Nicholas Yunker_2]

I am interfacing a 5V PWM signal with an STM32F030K6T6 MCU using PB0. According to the datasheet this pin is 5V Tolerant. In the past, regardless of a pin's "tolerance" to 5V I have always used a level shifter to change this 5V signal to a 3.3V signal before it gets to the MCU; "Just to be safe". This application I am trying to limit the number of parts on the PCB for both size and cost reasons. Testing on a Nucleo board seems to work and the MCU seems to tolerate this well, but for long term use in the field is it better to run this signal through a level shifter or does it not matter since the pin is "5V Tolerant"?

[TDK]

> It may seem redundant - but to confirm can we interface a 5V UART Input signal to the UART Rx pin which is 5V tolerant ie FT? 

Yes, if the chip is powered prior to receiving a 5V signal, as stated above.