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Simulators >> Circuit Simulators >> auto-check & save before simulation for spectr
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Message started by stephen on Jul 1^st, 2004, 1:08pm

Title: auto-check & save before simulation for spectr
Post by stephen on Jul 1^st, 2004, 1:08pm

Is there any way to have spectre automatically check and save the schematic to be simulated whenever I start a simulation?

So often, I forget to do check & save before running a simulation. spectreS doesn't have this strange requirement. Only spectre has.

Any ideas?

Title: Re: auto-check & save before simulation for sp
Post by Andrew Beckett on Jul 1^st, 2004, 9:40pm

Stephen,

By the way, the requirement is to "check" (the save is not important), if necessary. In essence this is to ensure that the connectivity information in the database has been updated since the last modification for each cellView in the design hierarchy being netlisted.

All netlisters (including spectreS) have this requirement. However, spectreS does a hierarchical check first before it starts to netlist, and that's why you don't see it. When the spectre direct interface was added back in IC443, it was found that having to go around and check which cellViews needed checking took a similar amount of time as doing the netlisting - so your netlisting time doubled (don't take this as an exact figure, I can't remember as it was a few years ago). This was seen as rather an overhead if you hadn't actually changed anything, or had already done the check yourself. Of course, for single cellView simulations, it probably doesn't take very long to netlist anyway, but imagine very large, multi-schematic designs.

The netlister does tell you if it encounters a block which needs re-extracting (i.e. checking).

If you wanted to get the spectre interface to do the check first, then that would be possible. What you could do is to customise the menus when using the spectre interface - take a look at:

<instdir>/tools/dfII/etc/tools/menus/spectre.menus

You could put wrappers around the sevNetlist.* functions which called schCheck() or schCheckHier() first, and then replace the menu entries with these wrapper functions.

Alternatively, just get used to doing a check whenever you modify anything - you're going to need to do it sooner or later for other tools anyway.

Regards,

Andrew.