Integrated circuit devices are provided that include power detection circuits
that indicate whether power supplies have reached functional voltage levels. The
power detection circuits include latches coupled to power supplies that can detect
whether all the power supplies have reached functional voltage levels, logic circuits
to provide appropriate output signals, and well bias circuits that supply current
to the power detection circuits. Well bias circuits provide current from first
power supplies to reach functional voltage levels so that indication may be provided
from the power detection circuit without requiring functional voltage levels of
all power supplies. Outputs from power detection circuits can be combined with
control signals, for various applications. Applications include holding an integrated
circuit device in reset until power supplies have reached functional voltage levels.