This is a simple Pseudo Random Bit Sequence Generator Circuit Diagram. A binary sequence is a sequence of bits, i.e. A BS consists of ones and zeros.In this circuit, an additional exclusive-OR gate is connected after the modulo-2 feedback, with CI and R2 applying the supply turn-on ramp into the feedback loop.
This provides sufficient transient signal so that the PRBS generator can self-start a power-up. A shift-register length of 10 is shown with feedback at stages 3 and 10, providing true and inverted maximal length sequence outputs. This technique applies an input directly to the feedback loop.
Therefore, it`s considered more reliable than applying an RC configuration to the shift-register reset input to create a random turn-on state.