Manchester codes are a way to combine clock and data into a single stream and send it serially over a communications link, wireline or wireless. Manchester encoding is relatively simple and is basically a modulo-2 operation with the variables being the clock and data. The clock is actually twice the frequency of the original data clock. Care must be taken to make sure that there are no glitches or spikes in the resulting waveform. Manchester decoding on the other hand is much more involved and is not a trivial operation. There are a number of techniques to do this. Some are software based, some are hardware based. Some are based on time delays while others are based on PLL type circuits. The techteam at Signal Processing Group Inc., has analyzed a number of these techniques and come up some circuits that do Manchester decoding. Interested users may contact SPG at http://www.signalpro.biz for details. A NDA may be required.