Abstract: A method and apparatus is provided for the implementation of a measurement and adjustment mechanism within a semiconductor die that facilitates adjustment of the magnitude of voltage generated by one or more voltage reference generation circuits on the die. In a first embodiment, the output voltage magnitude of a bandgap reference circuit may be measured and adjusted. In a second embodiment, the output voltage magnitude of a voltage regulator circuit may be measured and adjusted. Programmable circuit elements, such as programmable resistors, may first be programmed during a configuration event of the die to determine the optimal configuration settings of the one or more voltage reference generation circuits. The optimal configuration settings are then used to program the state of one or more eFuses to maintain the optimal configuration settings for the duration of the semiconductor die's lifetime.