In Reply to: Re: How to recover clock from Manchester Encoded Data? posted by Russ Kincaid on 07/04/03 at 1:14 PM:
As I recall, to recover the clock from a manchester bit stream you need to delay the signal by 1/4 the bit period, then XOR the delayed signal with the original signal. Then you run this XOR output into a PLL. However, you are now going to phase-lock it to a clock at 2X the bit rate. Because it is 2 times the bit rate, you have an ambiguity, where each positive clock edge occurs at either the beginning or the middle of the bit period, but you don't know which! I believe there is a simple way to resolve this ambiguity, but I have forgotten it. If anybody knows how to do this, please advise. thanks!