Subject: HSPICE incorrect V-I tables?

From: Roland James Chang <[email-masked]>
Date: Fri, 16 May 1997 16:04:02 -0700 (PDT)

Hello, I am having trouble trying to get output I obtained using
HSPICE to match the example files provided with the s2ibis2 utility
(generated with spectre supposedly)

there are four examples, and likewise four example .ibs files provided
with the s2ibis2 utility,

my_buf.ibs
my_tri.ibs
my_chip.ibs
my_mpow.ibs

Take for example my_chip.ibs,

When I generated the chip.ibs file for it, the tables for the model
--input-- matched the example my_chip.ibs file fine as shown below in
shortened form: (POWER_clamp matched as well)

******** my_chip.ibs file (included with s2ibis2 utility) *******
.
.
.

|************************************************************************
|                              Model input
|************************************************************************
|
[Model]          input
Model_type       Input
C_comp           5.00pF              5.00pF              5.00pF
|
|
[Temperature Range]       27.00               100.00              0.000
[Voltage Range]           3.30V               3.00V               3.60V
[GND_clamp]
| voltage     I(typ)              I(min)              I(max)
|
  -3.30      -30.81mA            -32.43mA            -30.24mA
  -3.20      -29.63mA            -31.24mA            -29.05mA
  -3.10      -28.44mA            -30.06mA            -27.86mA
  -3.00      -27.25mA            -28.87mA            -26.67mA
  -2.90      -26.07mA            -27.69mA            -25.48mA

******** chip.ibs which I generated using HSPICE *******
.
.
.

|************************************************************************
|                              Model input
|************************************************************************
|
[Model]          input
Model_type       Input
C_comp           5.00pF              5.00pF              5.00pF
|
|
[Temperature Range]       27.00               100.00              0.000
[Voltage Range]           3.30V               3.00V               3.60V
[GND_clamp]
| voltage     I(typ)              I(min)              I(max)
|
  -3.30      -30.91mA            -32.27mA            -30.42mA
  -3.20      -29.72mA            -31.09mA            -29.23mA
  -3.10      -28.53mA            -29.90mA            -28.04mA
  -3.00      -27.35mA            -28.72mA            -26.85mA
  -2.90      -26.16mA            -27.53mA            -25.67mA
  -2.80      -24.98mA            -26.35mA            -24.48mA

However, when I looked at the V_I tables generated for the model
--driver-- and --tristate driver-- I found that my HSPICE files had
ridiculously huge values:

******** my_chip.ibs file (included with s2ibis2 utility) *******
.
.
.

|************************************************************************
|                              Model driver
|************************************************************************
|
[Model]          driver
Model_type       Output
Polarity         Non-Inverting
C_comp           5.00pF              5.00pF              5.00pF
|
|
[Temperature Range]       27.00               100.00              0.000
[Voltage Range]           3.30V               3.00V               3.60V
[Pulldown]
| voltage     I(typ)              I(min)              I(max)
|
  -3.30       -1.94A              -1.61A              -2.12A
  -3.10       -1.78A              -1.48A              -1.94A
  -2.90       -1.62A              -1.35A              -1.76A
  -2.70       -1.46A              -1.22A              -1.59A
  -2.50       -1.30A              -1.10A              -1.41A
  -2.30       -1.14A              -0.97A              -1.23A
  -2.10       -0.98A              -0.84A              -1.06A
.
.
.
|
|************************************************************************
|                         Model tristate_driver
|************************************************************************
|
[Model]          tristate_driver
Model_type       3-state
Polarity         Non-Inverting
Enable           Active-Low
C_comp           5.00pF              5.00pF              5.00pF
|
[GND_clamp]
| voltage     I(typ)              I(min)              I(max)
|
  -3.30       -1.88A              -1.57A              -2.04A
  -3.20       -1.80A              -1.51A              -1.96A
  -3.10       -1.72A              -1.44A              -1.87A
  -3.00       -1.64A              -1.38A              -1.78A
  -2.90       -1.56A              -1.31A              -1.69A
  -2.80       -1.48A              -1.25A              -1.60A
  -2.70       -1.40A              -1.19A              -1.52A
  -2.60       -1.32A              -1.12A              -1.43A
  -2.50       -1.24A              -1.06A              -1.34A
.
.
.

******** chip.ibs which I generated using HSPICE *******
.
.
.

|************************************************************************
|                              Model driver
|************************************************************************
|
[Model]          driver
Model_type       Output
Polarity         Non-Inverting
C_comp           5.00pF              5.00pF              5.00pF
|
|
[Temperature Range]       27.00               100.00              0.000
[Voltage Range]           3.30V               3.00V               3.60V
[Pulldown]
| voltage     I(typ)              I(min)              I(max)
|
  -3.30     -3.777e+21A         -1.000e+25A         -3.957e+19A
  -3.10     -3.777e+21A         -1.000e+25A         -3.957e+19A
  -2.90     -3.777e+21A         -1.000e+25A         -3.957e+19A
  -2.70     -3.777e+21A         -1.000e+25A         -3.957e+19A
  -2.50     -3.777e+21A         -3.526e+24A         -3.957e+19A
  -2.30     -3.777e+21A         -7.015e+21A         -3.957e+19A
  -2.10     -3.777e+21A         -1.395e+19A         -3.957e+19A
.
.
.
|************************************************************************
|                         Model tristate_driver
|************************************************************************
|
[Model]          tristate_driver
Model_type       3-state
Polarity         Non-Inverting
Enable           Active-Low
C_comp           5.00pF              5.00pF              5.00pF
|
[GND_clamp]
| voltage     I(typ)              I(min)              I(max)
|
  -3.30     -3.777e+21A         -1.000e+25A         -3.957e+19A
  -3.20     -3.777e+21A         -1.000e+25A         -3.957e+19A
  -3.10     -3.777e+21A         -1.000e+25A         -3.957e+19A
  -3.00     -3.777e+21A         -1.000e+25A         -3.957e+19A
  -2.90     -3.777e+21A         -1.000e+25A         -3.957e+19A
  -2.80     -3.777e+21A         -1.000e+25A         -3.957e+19A
  -2.70     -3.777e+21A         -1.000e+25A         -3.957e+19A
  -2.60     -3.777e+21A         -1.000e+25A         -3.957e+19A
  -2.50     -3.777e+21A         -3.526e+24A         -3.957e+19A
  -2.40     -3.777e+21A         -1.573e+23A         -3.957e+19A 
.
.
.

I think someone mentioned this in their replies to my previous posts, but
it was a short reply.  Anyone experience this problem?(and why does it
happen?) And if so, how did you correct it?

Once again, many thanx! 
(and sorry for all the traffic!)

roland

*************************************************************************
*Roland Chang                          | email: [email-masked]           *
*Simon Fraser University               |        OR                      *
*School of Engineering Science         |        [email-masked]  *
*3rd year Computer Engineering Option  |                                *
*************************************************************************