Waveform/Eye Diagram Analysis Parameters

  • Number of random pulses: The number of random pulses excited to the simulating net during the eye diagram analysis.
  • Bit pattern style: Select the numerical method among random, ABS (Artificial Bit Stream) and PRBS (Pseudo Random Bit Stream) for generating the bit sequences. ABS (Artificial Bit Stream) is a method designed to provide a large pattern of bits to show worst case signal transmission quality of the net that would quickly converge the eye diagram. PRBS (Pseudo Random Bit Stream) is the mostly common method deemed as an industry standard.
  • Bit pattern length – If bit pattern style is ABS or PRBS, choose the bit pattern length.
Using the Random bit pattern, state of each bit of bit stream is randomly selected. Arbitrary (Random) Bit Stream (ABS) is a popular random bit stream used to generate eye diagrams. The ABS pattern is designed to provide a large random pattern of bits that would quickly converge to the eye diagram showing worst case tolerances. Pseudo-Random Bit Sequence (PRBS) is another popular bit stream style generating random-like bit sequence created from a specified pattern length. For example, when 2^7 is selected for the pattern length, 127 (2^7-1) unique data words are assembled according to the sequence.