Jeffrey, Thanks for the feedback. Looking at the spectrum of an un-encoded/raw data stream versus an 8b/10b-encoded data stream, I can see how the power spectral density will be increased at a frequency equal to the data rate/2, which would provide more information for a PLL to synch onto. If this is the case, is there a way of analyzing exactly how much better a PLL can synch when using 8b/10b vs when not using 8b/10b? If there is, can the analysis be generalized to allowing me to determine how often transitions need to be in order for a PLL to lock? Thanks, Pat > > # What's the purpose of 8b/10b encoding? > > Generally as I understand, it is to be able to recover the clock by > ensuring some number of transitions per period (8 per 10?). > Clocks change > period frequently when working at high speeds, due to > temperature, etc... not > to meantion the fact that otherwise the sending clock would > inevitably be > out of phase, plus period, of your receiver's clock. > > ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu