TPS3828: the timeout sequence when WDI changed from HIZ to low impedance(level low)

Part Number: TPS3828

Dears

 WDI is in HIZ when power up, and after 3s, the WDI will became level low, we are wondering how long it will take to make a timeout reset?

in this case, the time out might be a range. like what is the internal reset OSC frequency? and when is the watchdog time start point when WDI from HIZ to a level low.

Thanks

Jun Shen