PURPOSE: To completely synchronize a carrier with time by counting the pulse of the carrier to generate time.

CONSTITUTION: The carrier is generated by a carrier oscillator 1, the carrier pulse is counted by a counter 2 and a logical condition is inverted at every prescribed count value. An inversion time is T/2. When the output from the counter 2 is inputted to a microcomputer 3, the microcomputer 3 detects a falling edge and, if detected, outputs L or H. Therefore, the data outputted from the microcomputer 3 is latched into a D type flip-flop 4 at the rise edge of the output waves from the counter 2, so the data can be outputted at every time T and synchronization with the carrier is obtained. Thus, a softtimer is made unnecessary, a software is simplified and the carrier is completely synchronized with time T.