- + Issue 13: NaN & 'X'

[Kevin Cameron, 23 Jan 2001]


I would like to introduce NaN into Verilog-AMS for a couple of reasons:

  • For initialization of 'real' type values.
  • Any real arithmetic function whose result depends on an 'X' (or 'Z') digital value should have the result NaN.

    It will be illegal to assign NaN to a branch, but the user can test for NaN e.g.: 

      if (Vout != NaN) V(out) <+ Vout;

    This may help later with VPI functions that return can return NaN.