TMS320F28235: VDDIO out of recommended condition: influence on GPIO output

Part Number: TMS320F28235

Hi expert,

My customer is using F28235, they use a voltage monitor to monitor VDDIO and will reset the device when VDDIO is under 2.7V.

We get the recommended VDDIO from datasheet which is between 3.135V and 3.465V so we care about what will happen when VDDIO is in between 2.7V and 3.135V.

When the output of a GPIO being high with no problem?

What will VOH become when voltage is in this range?

How did you test to decide the recommended voltage?

Thanks

Sheldon