Honored Contributor
Honored ContributorHi Dave,
--- Quote Start --- I'll take a look now (I didn't have time last night). --- Quote End --- a big thanks, that you take care for the communities problems, the way you do! So now worries, I can wait! (escpecially because it ist weekend, I haven't expected to get an answer at all....) --- Quote Start --- The TTK examples do not use alignment *at all*. --- Quote End --- Well, that explains a lot, at least for me ...... :rolleyes: --- Quote Start --- What does that mean? The TTK receive side simply gathers 32-bits or 40-bits from the parallel output of the receiver, loads those into the matching LFSR (an LFSR in the receiver that matches the transmitter polynomial), and then the output of the LFSR should match the next 32-bits or 40-bits from the parallel output. The receiver parallel bits are XORed with the expected PRBS bits, and any differences are counted as bit errors. The TTK receiver is dumb ... that is the beauty of the TTK ... if it doesn't work, you know you're in trouble If you want to transfer actual data over a link, then you need to take care of the alignment. The simplest method is to use 8/10B encoding. --- Quote End --- Those are the sentence of explanation I was looking for for a couple of days. I wonder, why Altera puts tens of thousands pages of documentation together, but often lacks the simplest form of explanation. Well, maybe it is my own stupidity to not realize or know about all those PRBS facts, but anyway, thank you Dave, this clears up so much in my misunderstanding and really helps to focus on the main target now (->implementing alignment in my own design instead of trying to understand how alignment works in the TTK....) Thanks, Maik
