A method and system is provided for creating a tap controller in a slice for use during custom instance creation to avoid the need of a boundary scan synthesis tool. Aspects of the present invention include during slice creation, using a software tool to create a test access port (TAP) from slice resources; during instance creation, allowing a customer to design a custom chip using the software tool to select which structures to use on the slice; and based on the customer selections, reconfiguring at the instance level connections between the tap controller and the selected structures.