Subject: Re: IBIS standard inconsistency

From: Mike LaBonte <[email-masked]>
Date: Tue, 01 Aug 2000 08:36:31 -0400

The IBIS spec distinguishes between keywords and subparameters. Keywords are
enclosed within square brackets. The spec examples of keywords have space
separators, even though the spec says that underscores are allowed. The use of
opening and closing brackets makes it easy to parse these, even though they
may appear as multiple words. The spec also says that underscores and spaces
are equivalent. So even though the spec examples use [GND clamp], parsers
are supposed to recognize [GND_clamp] as being equivalent.

Subparameters have no brackets. The spec states "Spaces are not allowed in
subparameter names". An example of a subparameter name is Model_type.
Although parsers certainly can handle multiple word sequences, it works out
better that subparameters are always a single word (no spaces).

Mike LaBonte
Cadence Design Systems

Stephen Nolan wrote:
> 
> In the IBIS standard, the keywords [IBIS Ver] and [File Rev] appear to the the
> only keywords that have capitalized words other than the first word (the word
> IBIS being completely capitalized accepted as an acronym). All other keyword
> have the first word capitalized followed by the other words lower case. Eg.
> [Comment char], [File name], [Voltage range]....
> 
> Why is there an inconsistency in the style of these keywords?
> 
> Also, some multiple-word keywords use an underscore between words instead of a
> space. Eg. [GND_clamp], [POWER_clamp].
> 
> Again, why the inconsistency?
> --
> Regards,
> Stephen M. Nolan