( ESNUG 306 Item 9 ) ---------------------------------------------- [12/3/98]
Subject: Why Does Synopsys Use The "Find" Command Everywhere In Their Docs?
> This question stems more from curiosity than any design issue. I have
> noticed that in the majority of tutorial/sample scripts for Synopsys'
> Design Compiler, the "find" command is used to locate signals by their
> full name, for input to other commands. For example:
>
> create_clock -period 50 find (port, clock)
>
> Can anyone provide me with a reason as to why the first construct would
> be used, other than for the purpose of displaying your understanding of
> the find command?
>
> - Jamie Travers
> Ericsson Mobile Communications AB
From: Jan Decaluwe <jand@easics.be>
Because dc_shell maintains multiple namespaces for different types of
objects, such as pins, ports, clocks, nets etc., and many commands can work
with various types.
With 'find' you specify in which namespace you are looking, or, to put it
differently, which type of object you want. It's good practice to use
it, because the "reasonable default" may not always be what you want.
E.g. note the difference between:
report_timing -from clockpin
report_timing -from find(clock, clockpin)
Regards,
- Jan Decaluwe
Easics Leuven, BELGIUM
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