WaVEFORMS FOR BIRD12.1

          Bob,

          If I understand your question, for the Vcc/2 waveform,
          wouldn't (4) be the only valid option? Option (2) would
          also be correct if the load were 100 ohms each, for a total
          Thevenin equivalent of 50 ohms. Or am I out in left field?

          Will

To Jon Powell, Arpad Muranyi, and IBIS Committee:

This is an open implementation preference question based on the waveforms
you have sent. In particular, refer to Jon Powell's "Synchronizing
Measure AC Waveforms ... " document recently sent which illustrates
the synchronization of rising and falling waveforms measured into
50 Ohm loads at 0, 2.5 and 5V.

How do you "blend" certain data combinations that would be allowed via the
BIRD12 [Rising waveform] and [Falling waveform] mechanisms? And which
form would you prefer seeing?

Cases --> (1) (2) (3) (4)

Low_To_High:
  50 Ohm to Vcc * *
  50 Ohm to Vcc/2 * *
  50 Ohm to GND * * *

High_To_Low:
  50 Ohm to Vcc * * *
  50 Ohm to Vcc/2 * *
  50 Ohm to GND * *

Note, Case (1) corresponds to the [Ramp] specification conditions in IBIS
Version 1.1.

Bob Ross
Interconnectix, Inc.
Received on Tue May 10 22:54:38 1994