> I think restricting the value non-negative signed expression > is better. > If you treat the expression as unsigned, you will never see a negative > number, so your warning could never be issued. OK, good point. But we don't want sensible, narrow, unsigned values to be treated as if negative just because their MSB happens to be set... logic [7:0] delay = 8'h80; // +128, not -128 ... #delay ... So the signing of the expression must be self-determined, and if it's signed and negative then we stipulate an error. I still think the error should be non-fatal, and the delay performed by the tool should be the unsigned'() value of the expression. -- 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 TThe 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 01:06:17 2007
This archive was generated by hypermail 2.1.8 : Tue Feb 13 2007 - 01:06:53 PST