1. A method of modular circuit design for a programmable logic device (PLD), comprising: defining a static module and a reconfigurable module; defining at least one logic interface macro within an implementation area of the reconfigurable module; implementing the static module using at least one routing resource in the implementation area of the reconfigurable module coupled to the at least one logic interface macro; recording the at least one routing resource in a list of used routing resources; and implementing the reconfigurable module using the list of used routing resources.