APPARATUS FOR REAL TIME CLOCK FREQUENCY OFFSET DETECTION AND METHOD THEREOF

摘要

PURPOSE: An apparatus for detecting a real time clock frequency offset and a method thereof are provided to low a product cost by providing necessary and exact real time clock frequency offset. CONSTITUTION: An overlap detection unit(100) generates an overlap signal by receiving a reference clock which can be inputted from the outside and a real time clock which is generated from a quartz oscillator. The overlap detection unit includes an AND gate which performs an AND operation of the reference clock and the real time clock. An envelope signal generation unit(200) can generate an envelope signal by detecting an envelope from the overlap signal. A frequency counting unit(300) can calculate the frequency of the envelope signal by receiving the envelope signal and the reference clock detected from the envelope signal generation unit. The frequency counting unit obtains the frequency of the envelope signal by counting the pulse frequency of the reference clock during a cycle of the envelope signal.