- + Issue 922: (14) Section 8.3.6.4 and 8.3.1 : Clarification on X and Z .

[Jon Sanders, 1/22/2001]

  (14) Section 8.3.6.4 and 8.3.1 : Clarification on X and Z .
  
    
   These sections should be enhanced to ensure that users and implementers understand that when accessing a digital net, X and Z
   must be dealt with prior to assigning a value to a variable and certain functions like case, casex, casez, ===, and !== need
   to be used to prevent errors.
   We need to close on if == and != can be used in analog on digital signals and if so does X or Z mean a failure of the
   comparison? Supporting them would require being able to do comparisons against X and Z only. The bottom line is analog cannot
   be assigned a value of X or Z. Do we need to allow the user to specify what X and Z would be set to?
     Recommendation: Currently we should limit analog to not support == and != when the signal is digital and contains X or Z.
     We should clarify this more in the LRM with the core agreement that signals cannot be set to X or Z in analog.