Cadence Tutorial
Spectre Netlist Extraction with
Cadence
Authors: David
Donofrio, Jos Sulistyo, Meenatchi Jagasivamani and Carrie Aust
This tutorial explains how to extract
a Spectre netlist from your cellview from either the schematic or layout view.
- From Virtuoso
(the layout view):
a) Get the extracted view of
the layout:
- Select Verify -> Extract.
- To extract resistances and
capacitances for NCSU
kit:
- Click the Set Switches button.
- Select Extract_parasitic_caps, Extract_cap, and
Extract_resistor option. Note that
Extract_cap (extracts intentional, non-parasitic capacitors) and
Extract_parasitic_caps are not the same option.
- In the CIW, type "NCSU_parasiticCapIgnoreThreshold=x" with x
being the maximum value of parasitic capacitance to ignore (in Farads) -
1e-18 is a typical value.
- Leave all other options as default.
- Click
OK.
- Click
OK.
b) Start Analog Artist:
Select Tools -> Analog Environment from
the extracted window.
NOTE: By starting Analog Artist from
Composer the current extracted layout will automatically be used as the target
design
c) Go to Spectre
Netlist Simulation Procedure.
- From Composer (the
schematic view):
a)Once the schematic is complete,
place pins (Add->Pin . . . or 'p'
shortcut) on signals you wish to name
These are the
signals that you will later be able to easily plot and stimulate.
Designate pin to be input, output or input/output
(recommended for Vdd and Vss)
a) Choose
Design-> Check and
Save
from the schematic window
b) Start Analog Artist:
Select Tools -> Analog Environment from
the schematic window.
NOTE: By starting Analog Artist from
Composer the current schematic will automatically be used as the target
design
c) Go to Spectre
Netlist Simulation Procedure.
- NOTE:When using both
switch-level and gate-level logic in a schematic
- Extract standard cells
corresponding to the gates in your schematic
a) Open the extracted view of a standard cell in Cadence Virtuoso.
b) Follow
instructions for extraction from layout given in the Netlist Extraction Procedure below. The
HSPICE netlist is the subcircuit definition of the corresponding gate. (Ex: wand2_2.sp)
- Extract schematic for Netlist
using instructions given in the Netlist
Extraction Procedure below.
- Include the subcircuit definition
in the top-level circuit HSPICE file using a .include statement. (Ex: ?.include
?./wand2_2.sp??)


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