Re: SPICE-to-IBIS conversion for I/O Buffer

Eric,

I think you are missing something. If your conversion worked for Output and
3-state, you must have defined a input/enable pin in your .s2i file. This
is necessary to put the output in High/Low/Tri-state modes by SPICE.

This same Input pin information will be used for [Ramp] or V/T waveforms.

For example, if this is part of the .s2i file defining the Input and Output
models:

|
| Node Signal Model
[Pin]
1 gg gnd GND
2 vv vdd POWER
3 a A MyDevice_IN
4 b0 B0 MyDevice_OUT
-> 3
|

Your s2ibis2 generated [Ramp] .spi file should look like this:

.
.
RLOADS2I b0 vv 50 # Pin b0 is an Output
VCCS2I vv 0 DC 3.3
VGNDS2I gg 0 DC 0
VINS2I a 0 PULSE(2 0.8 0 1e-10 1e-10 2e-08 4.04e-08) # Pin 'a' is input
.TEMP 27
.OPTIONS INGOLD=2
.TRAN 1e-10 1e-08
.PRINT TRAN V(b0)
.
.

Hope this helps.
Syed
Cisco Systems, Inc

>
> I am trying to create an IBIS model for an I/O buffer using the following
SPICE-to-IBIS conversion program that I downloaded.
>
> SPICE-to-IBIS conversion(IBISv2.1): North Carolina State University
>
>
> By inspecting all the SPICE files that the conversion program created, I found
out that it never supplied any voltage at the input pin and the enable pin, not
even for [RAMP] measurement. Is this a bug in the conversion program, or did I
miss something (or parameters)?
>
> Any help will be greatly appreciated. Thanks in advance.
>
> PS: I have tried the conversion program for input, output, and 3-state. They
are all fine during the conversion without the problem described above.
>
> Yours truly,
> Eric Hui.
>
>

 
Received on Mon Aug 21 17:21:14 2000