How To detect electroic Clock Signal

[aamir]

I want to build a circuit which detect whether  electronic clock signal is preset or not and transfer this information to Host PC .How to implement  circuit using mirocontroller  to detect clock Signal is present or not.

[DTiziano]

You do not mention witch signal is the clock or the frequency involved.
If it is a square wave you can use the controller timer input (ex. PIC) and read/reset it every X mS.
To avoid wrong detection you can use a threshold on the count read.
When Count is > threshold = signal present.