Subject: Help

From: sunweifeng <[email-masked]>
Date: Wed, 10 Nov 1999 10:02:13 +0800

Hi Sir,

  There are some questions for the motorola's ibis model of mpc860, hope

you can help me.
  I simulated my design using above ibis model by signoise of cadence,
and found:

1. The  pullup voltage range of this model is -10V to 5V,  do think it
is right?
If not, would you please to tell me how to modify it ?
2. The receiver simulation waveform have overshoot at the falling and
undershoot at the rising  when the I_O1 or I_O2 buffer of mpc860 is a
driver. I think the waveform is not correct, do you think so?
3. If remove the rising waveform and falling waveform parameter from the

model, the clamp have only the dv/dt, simulated the same net again, the
receiver waveform don't have the overshoot at the falling and undershoot

at rising, but the high level of receiver waveform is not 3.3V, it is
2.6V. Maybe it also is not right. I want to know how modify the model
parameter to increase the high level to 3.3V?

Atteched file is ibis model of mpc860, hope you can help me to check it
and tell me why,  and hope you can tell me how to check a ibis model
accuracy .
thanks a lot.

Best Regareds,

Sun Weifeng