Cadence Mixed-Signal Circuit Design Environment User Guide
Interface Element Macro Models
October 2003
50
Product Version 5.0
IE Model Files for Spectre Simulation
The
.S
model file for SpectreS simulation is converted to a
.scs
file for Spectre simulation
using these steps:
1. Count parameters. The number of parameters in the
.S
model file is the highest number
&n
expression. The number of parameters in the corresponding
.scs
file is 1 less than
this number because the interfaceNet is a net and not a parameter in the
.scs
file.
2. Choose names for the parameters in step 1. The parameter name for the A2D digital
destination must be
dest
. Other parameters can use the same names as in the CDF
component parameters.
3. Change SPICE constructs to Spectre constructs. Any SPICE constructs that cannot be
converted must be enclosed between these statements:
simulation lang=spice
...
simulation lang=spectre
4. Replace continuation characters. Change a trailing & character to a leading + character.
5. Enclose all components in an inline subcircuit construct. Use the IE model name for the
subcircuit name. Specify the analog interface net and ground in the subcircuit terminal
list. For example:
inline subckt MOS1_a2d (anode gnd)
...
ends MOS1_a2d
6. Add the parameter declaration. Be sure to add the parameter
dest
to A2D models. You
can also specify default values for each parameter.
7. Rename the IE primitive with the name of the IE model, such as MOS1_a2d. This
indicates that the IE primitive is the inline component.
8. Replace the
"&1"
parameter, which represents the digital destination, with
dest
.
Remove the quotation marks ("") from the
dest
parameter value of the IE primitive.
9. Replace the
&1
(unquoted) parameter, which represents the digital node, with
dnode
.
10. Replace the
&2
parameter, which represents the interface net, with the string
anode
.
11. Replace node 0 with
gnd
.
12. Replace parameters
&3
and higher with the corresponding Spectre parameter names.
13. (Optional) Make cosmetic changes to improve readability. You can make cosmetic
changes after the model has been tested.