AUTOMATIC SWITCHING SYSTEM IN GENERATION LOCKING

摘要

The apparatus selects an internal clock source or an external clock source by inspecting operating state of an internal and an external synchronous signal. The apparatus includes an internal and an external synchronous signal detector for detecting the existance of internal and external synchronous signal, a switch for supplying internal synchronous signal to a video signal generator according to control signal transmitted from an internal/external synchronous signal discriminator, an internal/external synchronous signal discriminator for generating control signal applied to the switch, and a collision detector for detecting collision of internal and external synchronous signal.