Integrated circuit devices with power supply detection circuitry

A power detection circuit coupled to a plurality of power supplies that provides an output signal that is at a first logic level when at least one of the power supplies has not reached functional voltage level, and is at a second logic level when all of the power supplies have reached functional voltage levels, comprising:

• a preset latch coupled to the power supplies;
• a plurality of clear latches, wherein each of the clear latches is coupled to the power supplies;
• a plurality of logic circuits, wherein each of the logic circuits is coupled between the preset latch and an associated one of the clear latches;
• a plurality of well bias circuits, each of which is associated with a respective one of the logic circuits, wherein each of the well bias circuits is coupled to at least two of the power supplies and supplies the associated logic circuit with current from a first power supply to reach functional voltage level;
• and
• a combinatorial circuit that combines outputs from each of the clear latches to provide the output signal.

A programmable logic device comprising:

• a power detection circuit coupled to a plurality of power supplies that provides an output signal that is at a first logic level when at least one of the power supplies has not reached functional voltage level, and is at a second logic level when all of the power supplies have reached functional voltage levels, further comprising:
• a preset latch and a clear latch that are coupled to the power supplies, wherein the output signal is substantially related to an output of the clear latch;
• a logic circuit that is coupled between the preset latch and the clear latch;
• and
• a well bias circuit that is coupled to the logic circuit and at least two of the power supplies.