Abstract: A method and apparatus for determining a voltage, such as a bias voltage, supplied by an integrated circuit. A nominal terminating resistor is connected across a first and a second input/output pads from which the voltage is supplied. The voltage is measured across third and fourth pads connected, respectively, to the first and second pads. In an alternative embodiment the functionality of the third and the fourth pads is multiplexed between chip operational circuitry unrelated to the voltage to be measured and a connection to the first and second pads for measuring the voltage.