A circuit architecture for expanded design for testability functionality is provided that includes an Intellectual Property (IP) core for use with a design for an integrated circuit (IC). The IP core provides an infrastructure harness circuit configured to control expanded design for testability functions available within the IC. An instance of the IP core can be included in a circuit block of the design for the IC. The infrastructure harness circuit can include an outward facing interface configured to connect to circuitry outside of the circuit block and an inward facing interface configured to connect to circuitry within the circuit block. The instance of the IP core can be parameterized to configure the infrastructure harness circuit to control a plurality of functions selected from the expanded design for testability functions based on a user parameterization of the instance of the IP core.