[IBIS] "corner_name" and BIRD 129

From: Muranyi, Arpad <Arpad_Muranyi@mentor.com>
Date: Fri Jul 13 2012 - 11:16:18 PDT

All,

I got an AR in the IBIS Open Forum meeting today to check
whether the "corner_name" column in the D_to_A converters
is required or not to make sure that the additional column
proposed in BIRD 129 would still work. This is what I found
in the v5.0 specification on pg. 109:

| The corner_name entry holds the name of the external model

| corner being referenced, as listed under the Corner

| subparameter.

|

| At least one D_to_A line must be present, corresponding to the

| "Typ" corner model, for each digital line to be converted.

| Additional D_to_A lines for other corners may be omitted. In

| this case, the typical corner D_to_A entries will apply to all
| model corners and the "Typ" corner_name entry may be omitted.

A similar text appears on pg. 127-128 for [External Circuit].
This means that "corner_name" is actually optional for the case
when only one D_to_A converter exists (per line), when that single
converter is expected to be used by the EDA tool for all corners.

However, even if we didn't make any changes to BIRD 129 (keeping
the "polarity" column optional), we wouldn't be in any trouble for
the following reason:

The "corner_name" and "polarity" columns may only contain the following
predefined values: "Typ", "Min", "Max" for the former, and "Inverting"
or "Non-Inverting" for the latter. This means that if either of these
optional columns are missing, the parser or the EDA tool would still
know which value belongs to the "corner_name" or "polarity" column.

So the BIRD would work as is, even if the parsing may not be as elegant
as it could be otherwise. I would like to get some feedback on this.
Should we change anything, or is it acceptable as it stands?

Thanks,

Arpad
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Received on Fri Jul 13 11:16:21 2012

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