SCM power supply

The problem of making a car has been bothering me , Just now I asked the customer service, read the product introduction and understood .
stm32 On the single chip microcomputer 3v3 and 5v:
Yes 3v3 If the power supply condition is good, it can be directly connected to 3v3 The pin supplies power to the board . without , SCM also comes with a voltage conversion chip , Can be 5v The power supply is connected to 5v The pin supplies power to the board .5v Pins can also be connected as needed 5v Peripheral modules for power supply , Provided by MCU 5v voltage .