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.