Mike,
I hope you will have better luck on getting this fixed
than I had. When I raised these questions I was told
that it was fine the way it was, after all, it is obvious
that if (Default 2) is there than that is in effect, but
if it is not there then the first number in the list is
the default, and it really didn't matter whether the first
number in the list was a repeat of another number in the
list or not...
I think it is a very poorly written spec and it should be
fixed, but others didn't think so.
Thanks,
Arpad
============================================================
From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] ;
On Behalf Of Mirmak, Michael
Sent: Monday, August 21, 2017 2:43 PM
To: IBIS-ATM (ibis-macro@xxxxxxxxxxxxx) <ibis-macro@xxxxxxxxxxxxx>
Subject: [ibis-macro] List, again...
Do we have a BIRD or other filing to address the issue below?
The following example appears in IBIS 6.1 on p. 196
(Strength (Usage In) (Type Integer) (Description "Strength of Driver")
(List 0 1 2 3 4) (Default 2)
(List_Tip "Extra Weak" "Weak" "Nominal" "Strong" "Extra Strong"))
However, the specification is quite clear that the first value in the List is
the default:
List <default value> <value> <value> <value> ... <value>
This defines a discrete set of values from which the user may select one value
Also, the specification is clear that "Default" is optional for data format
List (see p. 194).
The example is unclear as to which value is the truly the default: 0 or 2.
It's also unclear whether the first value in "List" may be a repetition of a
value elsewhere in the list (e.g., "List 2 0 1 2 3 4"). I would expect EDA
tools to differ considerably on how to interpret this.
So, if "Default" is used with "List", which default value takes precedence?
The first value in the list, or the value set by "Default"? Should the first
value in the list be a distinct value, repeated in the subsequent list?
- MM
