clock extraction

[mit_mohit]

How to extract clock if it is embedded with the data signal?

 

[Nigel Goodwin]

How to extract clock if it is embedded with the data signal?

I would imagine it depends entirely on the format used?, but your question is rather vague!. The most common type used is Manchester Coding, and a google search will find plenty of information about it.

 

[DigiTan]

Edge detection for DC and zero-cross detection for AC works for me. If it's Manchester anyway. By like a car after a hailstorm, we need serious detailing here.

 

[mit_mohit]

Sorry for not clearing specifying the problem.I want to extract the clock from normal data signal where '1' is represented by 1volt and '0' is represented by 0volt

 

[Nigel Goodwin]

Sorry for not clearing specifying the problem.I want to extract the clock from normal data signal where '1' is represented by 1volt and '0' is represented by 0volt

That's even MORE obscure, you need to specify EXACTLY what you are talking about 'normal' could mean anything?.

 

[mit_mohit]

simply 1 is represented y +1 volt and '0' is represented by 0 volt. Is there any method by which i can extract clock from such data signal? I mean there is no inbuit synchronisation in this type of format as compared to Manchester coding.

 

[Nigel Goodwin]

simply 1 is represented y +1 volt and '0' is represented by 0 volt. Is there any method by which i can extract clock from such data signal? I mean there is no inbuit synchronisation in this type of format as compared to Manchester coding.

You're still giving NO information about the signal?, do you mean it's a standard RS232 type - such as from a PC serial port to a modem?. The format of such signals is given by such details as '9600 8N1'.

If so, then you can't recover the clock information, because there's none there to recover - it's an asyncronous format.

Perhaps you might try asking for EXACTLY what you are wanting to do?, rather than a small part of what you think you need?.

 

[Styx]

or are you talking abt a clock signal multiplex with a data signal?

 

[Roff]

He is probably talking about good old (synchronous) NRZ.
With NRZ, you can't recover clock unless you can guarantee that there will be some minimum transition density, i.e., if the logic level never changes for a long period of time, clock cannot be recovered. Analog Devices has **broken link removed**, which has a patented phase detector, but it only works between 20MBPS and 160MBPS, and it requires thousands of clock cycles to acquire lock.
EDIT:
After rereading the OP, I realized that he specified "embedded clock", so this is probably not NRZ.