A machine readable, volatile or non-volatile memory medium, which is not a signal, containing a design structure in a data format, the design structure when processed by executing instructions on a machine is used in a design process for a circuit, the circuit for selectively connecting an integrated circuit to a plurality of external paths, the plurality of external paths including a first signal path and an external power supply, the circuit comprising:
- a second signal path internal to the integrated circuit;
- a power network internal to the integrated circuit;
- and
- an input/output element configured to switch amongst a plurality of modes including a first mode and a second mode, the first mode connecting the first signal path to said second signal path via said input/output element, the second mode connecting said power network to the external power supply via said input/output element.