Physical layer of Networking Hardware

prbs generator:

Random bit sequence using Verilog
prbs polynomials used in networking
Fibonacci form and Galois form

Fibonacci form: Another unique feature to this form is that the values in the shift register aren’t modified between when they are originally calculated and the output–making it possible to see then next LN output bits by just examining the shift register state. 

I have seen it used for prbs(peudo random binary sequence in ethernet transmission protocols for scrambler/descrambler, encoding pad, random pattern generation for loopback testing, Cyclic redundancy check(CRC) and so on), timer( non linear incremental timer, as lfsr normally has a fixed perioed)

References:
wiki
Generating Pseudo-Random Numbers on an FPGA
An example LFSR

ADC OSC(oversampling ratio):

The basics of sigma delta analog-to-digital converters
Delta-sigma modulation

Explaining SerDes:
(Chinese) SerDes Knowlege: notice the limitations of parallel transmission.

circuit noises:

simultaneously switching noise an overview/