Re: [vhdl-200x-ft] Questions/Remarks concerning fixed_pkg

From: <yannick.grugni_at_.....>
Date: Tue Feb 22 2005 - 01:22:10 PST
Hi David & Collin,
Thanks for your replay.

Collin, it's true that you can convince Cadence BuildGates to not write 
out netlists with negative indexes with set_global 
hdl_verilog_out_no_negative_index true. 
But it's the only synthesis tools which have a such command. Synopsys or 
Cadence RTL Compiler doesn't have a similar one.
Don't forget that converting negative indexes to positive indexes 
complicates a lot the formal verification between the original vhdl and 
the netlist.

David, concerning Synopsys I can guaranty you that even with 
(hdlin_enable_presto_for_vhdl = true) you can't compile "in1reg3 = in2reg3 
+ 3.1415". 
When I try to compile with synopsys (version 2004.12 or earlier) I get 
this error message : Generic error: REAL is not supported in synthesis. 
ELAB-2.
I will put for you in attachment with this mail 2 testcases (one which 
doesn't use any real ("test_constant_reals_std2.m.vhdl") and one which use 
them("test_constant_reals_std.m.vhdl")). 
The synthesis result of the 2 testcases must be the same but the only the 
one that doesn't use real ("test_constant_reals_std2.m.vhdl") can be 
synthesised with Synopsys.
Could you take a look and see from your side?




Kind Regards,
Yannick
 
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Yannick Grugni                              Design Competence Center 
Leuven
VLSI Engineer                                       Interleuvenlaan 74-82
Tel: +(32)16.390.742                            3001 Leuven
yannick.grugni@philips.com           Belgium
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Received on Tue Feb 22 01:23:34 2005

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