A clock-signal generator (e.g. a PLL or a DLL) uses non-volatile memory to store an analog control voltage that determines an output phase and/or frequency of the clock-signal generator. Locked loops take time to lock on a given reference frequency. To keep this time to a minimum, NVM 105 stores the control voltage during periods of inactivity, such as when the signal generator is powered down or in a standby mode. Non-volatile memory stores control voltages during operation in other embodiments to relax the area requirements otherwise required for integration capacitors to store phase and frequency information.