what will be the problems of using Single VDD Pin (48PIN) connect to VDD voltage by keeping other VDD pins open ?

[ARUN C]

I'm using STM32f030C8T6 controller 48pin package ,i want to know what are the difference between digital power supply pin and complementary power supply pin . and also need to know that can i use only Digital power supply to VDD voltage for running the IC?

[Uwe Bonnes]

It is the end of the world as we know it.

Using parts in a not specified way will lead to problems not specified.

[Tesla DeLorean]

The part doesn't start.

Groups of pin don't work or stop working.

Allowing other pins to float can cause unpredictable start behaviour.

Avoid lazy/sloppy design.

[TDK]

> and also need to know that can i use only Digital power supply to VDD voltage for running the IC

Not sure what you mean here. Any power supply that can source enough current can be used for VDD.