RE: Problem with clocked driver

Ali,

This buffer seems to have flip/flop in it which doesn't seem to get
initialized correctly at t=0 and both its pullup and pulldown drivers
seem to be on at t=0. This could be fixed if you could initialize
some of the internal nodes for t=0 using the .IC statement. However,
you can ignore this and just clock the buffer a few times before you
begin the actual sweep to get the IV curves.

So, to get a pulldown IV curve, I would set the input low, wiggle the
clock and then sweep the IV curve. To get a pullup IV curve, I would
set the input high, wiggle the clock and then sweep the IV curve.

Arpad Muranyi
Intel Corporation
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-----Original Message-----
From: Hassan Ali [mailto:hali@nortelnetworks.com]
Sent: Thursday, August 31, 2000 11:18 AM
To: ibis
Subject: Problem with clocked driver

I'm trying to create an IBIS model of a differential driver from its
encrypted HSPICE model. The driver operates with the P and N outputs each
terminated with 50 ohm to VDD (=1.8V). This driver has a couple of unusual
characteristics:

- transient simulation shows that at time=0 the driver output is around
950mV regardless of the input stimulus voltage.
- the driver has a clock input as one of the driver subcircuit parameters.
The driver output follows the driver input stimulus only upon receiving a
rising clock edge.

Does anybody know how I should go about creating the IBIS model of this
driver (say using s2ibis2 program)?

Thanks.

Hassan.
Received on Fri Sep 1 08:06:38 2000