Spectre Netlist Simulation - Graphical Interface
Authors: David Donofrio, Jos Sulistyo, Meenatchi Jagasivamani and Carrie Aust
This tutorial explains how to simulate your extracted Spectre netlist using Analog Artisit (graphical interface).
To simulate using spectre from the command line go to spectre simulation from the command line
Netlist Simulation Procedure when starting from Composer (schematic netlist):
From Analog Artist:
1. Choose Setup->Simulator/Directory/Host
a. Set Spectre to be the current simulator
b. Project Directory is top level simulation work directory (cadence will create multiple subdirectories under this one)
2. Choose Setup->Model Path
a. Type full path (including filename) of any model(s) needed for simulation
b. NOTE: The default model specified by Composer is d25.m (download it!).
3. If you wish to change this model name, it must be done in Composer by displaying an objects properties (Select object, press 'q' shortcut, change "Model Name" field - note that the '.m.' extension is implied)
4. Choose Outputs -> To be plotted . . . -> Select on Schematic
a. Schematic window will come to the foreground.
b. Click on any signals (i.e. the WIRE) you wish to plot, you will see the wire change color once it is selected
5. Choose Analysis -> Choose
a. Choose your desired Analysis
6. Example: Transient analysis, choose 'tran' and then type in the total time you wish to run (ex. 40n or 40e-9)
7. Choose Setup -> Stimuli
a. A window will appear where you may graphically set up the stimulus signals
7. Once you are done setting up a signal, choose "change"
NOTE: if you do NOT wish to stimulate a node that has been declared as input/output
8. Be sure to disable it by un-selecting "enabled."
a. Click the Green Traffic Light Icon (bottom right corner of Analog Artist) to run the simulation
9. If no warnings or errors occur, the simulation will run and all requested signals will be plotted
Netlist Simulation Procedure when starting from Virtuoso (layout netlist):
From Analog Artist:
1. Choose Setup->Simulator/Directory/Host
a. Set Spectre to be the current simulator
b. Project Directory is top level simulation work directory (cadence will create multiple subdirectories under this one)
2. Choose Setup->Model Path
a. Type full path (including filename) of any model(s) needed for simulation
b. NOTE: The default model specified by Virtuoso is d25.m (download it!).
3. Choose Analysis -> Choose
a. Choose your desired Analysis
4. Example: Transient analysis, choose 'tran' and then type in the total time you wish to run (ex. 40n or 40e-9)
a. Click the Green Traffic Light Icon (bottom right corner of Analog Artist) to run the simulation
5. If no warnings or errors occur, the netlist will be extracted and displayed.
a. The file generated by Analog Artist at this point is ready, once the inputs are stimulated., to be simulated by Spectre. In order to stimulate the inputs it is necessary to manually edit the file generated by Analog Artisit and add the stimiulus commands into the file. This can be done with any simple text editor, such as vi.
b. The file inverter.scs is an example of the output generated by Analog Artist for an extracted inverter layout with the necessary commands to stimulate the inputs added. The models used in this example may be found in the file d25.m (download it!).
From the command line:
1. After you have completed all the steps from within Analog Artist listed above:
a. Switch to the directory where spectre has placed your resulting netlist (will be given at the bottom of the Analog Artist window)
b. Open the netlist file (typically input.scs) and add the necessary stimilus commands, if you have not done so already.
2. The file inverter.scs is an example of the output generated by Analog Artist for an extracted inverter layout with the necessary commands to stimulate the inputs added.
a. To peform spice simulation, type the command.
spectre inverter.scs (where 'inverter.scs' is the name of the netlist file generated by Analog Artist)
3. To plot the results, type the command.
awd -dataDir inverter.raw/
(where 'inverter' is the name of the netlist file generated by Analog Artist)
NOTE: for the above to work, make sure inverter.scs is in your current working directory.
4. Four windows appear.
5. Activate "Result Browser" window: Click left buton on input.raw
6. Yellow node numbers show up on the right end of the hierarchy: Click right button on any nodes you wish to display.
7. "Waveform Window" displays the waveform.
8. To make a hard copy of the plot: Choose hardcopy menu from Windows menu on "Waveform Display" window.
9. A windows appears.
a. Verify Laser Writer is chosen as "Plotter Name".
b. Click "Send Plot Only to File.," and type in the file name. Click apply to generate a postscript file.
Additional Info:
For details of Spice and Spectre, refer to the online manuals. They can be opened as:
- cdsdoc &
- Choose the following menus in the sequence.
- IC Tools -> Analog and Mixed Signal Simulation
- -> For SPICE choose "HSPICE/SPICE Interface ..."
- -> For Spectre choose "Spectre User Guide."
IMPORTANT: There must be one blank line at end of file. Spectre is case-sensitive.
Comments to: ha@vt.edu
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