BIRD6 comment

Hello again IBIS flock:

Thanks Kellee for your comments, I agree with your "vdiff" terminology
change, or whatever people feel is best. Also, you raised a good
point regarding differential skew. For example, the National
DS3695A/DS3695AT/DS3696A/DS3696AT Multipoint RS485/RS422 Tranceivers
in the Interface Databook specify this and show a waveform. Another
column could be added for this in [Diff_pin].

I think using the POLARITY in the model instead of the sign of "vdiff"
is a good alternative. In that way the polarity of of "vdiff" could be
reserved more appropriately for a hypothetical differential device with
differential hysterisis (although I have not found such a device).

In doing Bird6, I had a problem in choosing whether one [Model] could
be used or two [Model]s were required, one for Positve and one for Negative
Polarities. In its present form, two [Model]s (even different models -
and I have seen cases where complementary outputs in some latches differ) can
be used if necessary, but one [Model] is sufficient. Your POLARITY
specification method would work for both cases.

Bob Ross
Interconnectix, Inc.
Received on Fri Jan 21 18:31:55 1994