Through a sweep of the operating temperature, frequency measurements are made of each individual crystal. The curve purity of the crystal is the defining factor in obtaining optimal performance in the TCXO circuit. An algorithm is applied to simulate the response curve of the crystal. The smoother the crystal response curve, the better the mathematical representation can be. Algorithms are then used to determine the necessary voltage adjustments needed in the circuit to discipline the crystal’s natural response curve over the operating temperature range. Registers in the TCXO are then set to respond to any changes in temperature that the TCXO will see in its operation.