Data encoding techniques used in Altera FPGAs

 In so far, most serial data streams look almost similar when watched on an oscilloscope, apart from a varying data rate.
This applies at least to binary data links that don't use modulation.

Thanks FvM. Serial data streams look similar in the scope, so how do they look like? Actually, because it looks like I just see some noise on the scope rather than my output signal coming out from transceiver connectors, I cannot imagine the signal is a sine wave or something else.

PS: I have read the handbook of stratix IV, and just got an overview idea. I did not remember that the data encoding is mentioned there. But, I will check again.

Thanks