RE: [sv-bc] time unit specification

From: <jonathan.bromley_at_.....>
Date: Fri Nov 21 2008 - 04:16:36 PST
hi Cliff, SV-BC,

> RTL models do not need a timescale as long as none of the models 
> compiled has a timescale or as long as the first model compiled has a 
> timescale.
> I put a timescale in my testbench and compile it first. After that, 
> 0-delay RTL models compile just fine.

That's a bit flaky in a separate-compilation flow, and doesn't help
if the TB and its friends have timeunit/timeprecision within 
their modules.

> (1) If the module has a delay, add a timescale in front of the module 
> - otherwise you are at compile-order mercy with other timescales in 
> the design.

But isn't that precisely why SV's timeunit/timeprecision is such
a good thing?  Using that exclusively, and eschewing `timescale,
means that I never need to worry about compilation order again
(at least, not from the timescale point of view).
-- 
Jonathan Bromley
Consultant

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Received on Fri Nov 21 04:35:28 2008

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