| 摘要 |
PURPOSE:To obtain a miniature and inexpensive synchronous signal discriminating circuit by discriminating digitally and automatically various inputted synchronous signals and sending a synchronous signal corresponding to an input signal specified beforehand. CONSTITUTION:On condition that a composite video signal CV is inputted to a terminal T1 and a composite synchronous signal CS or a horizontal synchronous signal HS is inputted to a terminal T2, this is automatically discriminated and the same signal as the composite video signal CS inputted to the terminal T1 or the horizontal synchronous signal is inputted to a terminal T3. On condition that the composite video signal CV is inputted to the terminal T1 and both the composite synchronous signal CS and the horizontal synchronous signal are inputted to the terminal T2, this is automatically discriminated and the same signal as the composite video signal CV inputted to the terminal T1 is inputted to the terminal T3. Since the various inputted synchronous signals are discriminated digitally like this, a gate array can be easily obtained and the number of parts can be decreased. |
