Re: how generate prbs in hspice?
A question is, just how "random" does this bit stream
need to be? If all you are looking for is a NRZ pattern
that exercises maximum and minimum transition
density, for example, that might be easiest built with
the stack of pulse sources (or, parallel rack of pulsed
currents, terminated by a burden resistor) that make
a few different patterns within the simulation interval.
If HSPICE has a tnoise type capability maybe it has a
noise source that acts in the time domain. Then all you
might need is a clocked comparator behavioral model
to clean it and make logic levels.