- 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.
