Stuart wrote: > My understanding has always been that for # unit delays, a > negative delay value is treated as an unsigned value. > I also thought that was in the 1364 LRM, somewhere. It is; a colleague has pointed out to me that 1364-2005 clause 9.7.1 clearly states that the value is sign-extended to the width of "time" and then treated as unsigned. So the simulator that treated the negative value as being zero was definitely violating 1364-2005. 64-bit "-1" treated as unsigned is an awful long time even if it's in picoseconds, and if it's counting cycles of a clock we're likely to be some way into heat-death-of-universe territory. Seems to me that stipulating a negative-delay warning for both ## and # would be a very good idea. -- Jonathan Bromley, Consultant DOULOS - Developing Design Know-how VHDL * Verilog * SystemC * e * Perl * Tcl/Tk * Project Services Doulos Ltd. Church Hatch, 22 Market Place, Ringwood, Hampshire, BH24 1AW, UK Tel: +44 (0)1425 471223 Email: jonathan.bromley@doulos.com Fax: +44 (0)1425 471573 Web: http://www.doulos.com The contents of this message may contain personal views which are not the views of Doulos Ltd., unless specifically stated. -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.Received on Tue Feb 13 07:54:26 2007
This archive was generated by hypermail 2.1.8 : Tue Feb 13 2007 - 07:54:44 PST