RE: [IBIS-Users] ibis version4 query

Arnab,
 
the file diffio.spi should contain the subcircuit definition for
diff_io_typ and models or other subcircuits used by this main
subcircuit. That's all it should contain.
 
trise and tfall are the rise and fall times of the analog voltage source
connected between nodes my_drive and my_ref. D_drive is a true digital
signal with 0 transition time. The D_to_A converts this digital signal
into an analog voltage with finite transition times that can drive the
transistor circuit of your driver.
 
It appears from this code excerpt that this model has another problem.
You have used the node my_ref in the D_to_A statement, but that node is
not defined in the Ports statement. I suggest that you use the
predefined node A_gnd instead. Also, it's generally a good idea to use
A_pdref and A_puref as connections in the Ports statement unless your
subcircuit has no power connections to Vcc and ground.  :)X
 
I'd be glad to test your model when you have completed it. You can send
it to me or to the IBIS model review committee.
 
Regards,
Weston
 

________________________________

From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org] On
Behalf Of Arnab Hazarika
Sent: Tuesday, June 07, 2005 3:18 PM
To: ibis-users@eda.org
Subject: [IBIS-Users] ibis version4 query


Hi all,
We are trying to incorporate the [External Model] parameter in ibis
models version 4.1.The pdf IBIS ver4.1 example shows an example 
 
[Model]Ext_spice_diff_buff
[External Model]
Language SPICE
Corner  Typ  diffio.spi  diff_io_typ
 
Ports A_signal _pos  A_signal_neg my_receive my_drive my_enable
| D_to_A d_port    port1          port2      vlow  vhigh trise  tfall
corner_name
D_to_A   d_drive  my_drive    my_ref    0.0   3.3    0.5n  0.3n  Typ
|
[End Model]
 
We had doubt regarding  what diffio.spi should contain?
 
Also what does the trise and tfall parameters signify?
 
Moreover if we include [External Model]  do we not have to contain the
pull up/down,GND/Power clamp? 
 
Could someone throw light on this ....Better if someone refers new ibis
models where this has been used?
 
Thanks in advance. 
 
Best regards
arnab hazarika
 
 

|------------------------------------------------------------------
|For help or to subscribe/unsubscribe, email majordomo@eda.org
|with just the appropriate command message(s) in the body:
|
|  help
|  subscribe   ibis       <optional e-mail address, if different>
|  subscribe   ibis-users <optional e-mail address, if different>
|  unsubscribe ibis       <optional e-mail address, if different>
|  unsubscribe ibis-users <optional e-mail address, if different>
|
|or email a written request to ibis-request@eda.org.
|
|IBIS reflector archives exist under:
|
|  http://www.eda.org/pub/ibis/email_archive/  Recent
|  http://www.eda.org/pub/ibis/users_archive/  Recent
|  http://www.eda.org/pub/ibis/email/          E-mail since 1993