VHDL Issue Number: 1095 Classification: Language Definition Problem Language Version: VHDL-93 Summary: Are time literals with real numeric parts exact? Related Issues: Relevant LRM Sections: 13.4.2, 3.1.3.1, 3.1.4 Key Words and Phrases: Based Literals Current Status: Submitted 1076-1993 Disposition: N/A Disposition Rationale: N/A Superseded By: N/A ----------------------- Date Submitted: 1995/06/13 Author of Submission: Clive R. Charlwood Author's Affiliation: Synopsys Author's Post Address: 700 E. Middlefield Rd Mountain View, CA 94043 Author's Phone Number: (415) 694-4307 Author's Fax Number: Author's Net Address: clive@vhdl.org ----------------------- Date Analyzed: TBD Author of Analysis: TBD Revision Number: $Revision: 1.2 $ Date: $Date: 1995/07/25 19:20:21 $ Description of Problem ---------------------- Is a literal of type time guaranteed to be exact? The LRM specifies that an implementation is only required to include six digits of precision for floating point types. Therefore it seems reasonable to argue that the expression (123456.789 fs = 123456789 us) is not always TRUE? Furthermore, since floating point numbers are not exact anyway one could argue that 1.001 ps is not always the same as 10001 ns. Proposed Resolution ------------------- TBD VASG-ISAC Analysis & Rationale ------------------------------ TBD VASG-ISAC Recommendation for IEEE Std 1076-1993 ----------------------------------------------- TBD VASG-ISAC Recommendation for Future Revisions --------------------------------------------- TBD