1. An apparatus, comprising: a plurality of input/output (“I/O”) ports; measurement circuitry to measure one or more electrical properties of one or more devices to be externally coupled to one or more of the I/O ports; and a I/O multiplexer bus coupled between the I/O ports and the measurement circuitry, the I/O multiplexer bus programmable to selectively couple the measurement circuitry to any of the I/O ports.