A global navigation satellite system (GNSS) enabled mobile device comprising a crystal oscillator and an automatic frequency correction (AFC) circuit may be operable to share the crystal oscillator between processing of cellular radio signals and processing of GNSS data messages. The GNSS enabled mobile device may be operable to enforce an AFC correction when the crystal oscillator drifts beyond a specific frequency error. The AFC correction may be allowed during time intervals corresponding to GNSS words at which decoding of these words is not required. The GNSS enabled mobile device may be operable to disable the AFC correction during time intervals associated with decoding of words while the crystal oscillator may drift within the specific frequency error range. After the decoding of one or more of words is completed, the AFC correction may be allowed during the time intervals corresponding to these words.