This page demonstrates the statistical simulation workflow on the EPDA environment. For license and tools requirement and environment setup, please refer to the Tools & license requirement and Install EPDA environment to a new working directory pages.
Following are the detailed steps to setup and run EPDA statistical simulations. The stat_library libraries used in the example are attached in this page.
On preparation to run the statistical simulation, users need to install the stat_library.cml CML to INTERCONNECT. Please refer to the Install Compact Model Library page for detailed steps.
Add/Create Design Libraries
Please refer to the EPDA Optical Network Analysis (ONA) using Virtuoso interop workflow for the first two steps on adding and creating design libraries. Sections:
- Add Design Libraries
- Create a Design Library
In this example, we are going to create a design library named "stat_example".
Create Schematic Design
With the first two steps finished, the "stat_example" library should be created. To create a circuit schematic design, click on the "stat_example" library and create a new cell named "testBench" with "schematic" type:
Click on OK and the Schematic Editor will be brought up. In the Schematic Editor, create an MZI circuit by going to:
Create -> Instance
and adding the "lum_ps_pn_stat_te_c_EO" cell from the stat_library library. Set the length of the phase shifter to be 0.005 m.
Use the same method to add another Phase shifter "lum_ps_pn_stat_te_c_EO" with length 0.0051 m. Add a CW Laser ("CWLaser"), two MMIs ("lum_mmi_1x2_strip_te_c") and a photodetector ("lum_pd_stat_c_EO") to the schematic editor from the same library and leave their properties as default .
[[Note:]] As indicated by the model names, the phase shifter model ("lum_ps_pn_stat_te_c_EO") and photodetector model ("lum_pd_stat_c_EO") are built with statistical variational data.
Lay out the models as shown below and connect the models by using:
Create -> Wire (narrow)
Then add electrical driving sources to the Schematic Editor from the "analogLib" library. Connect the cathode and annode ports of the photodetector and the phaser shifter on the lower branch to "vdc" sources and ground the sources to "gnd". Ground the annode port of the phaser shifter on the upper branch and drive its cathode port by the "vprbs" source with the following property:
The final MZI circuit schematic is shown below:
Setup Netlist Config
After schematic design in the previous step, now we can set netlist partition rules.
Create the HED config view through "Library Manager" by:
File -> New -> Cell View
Set the View type to "config":
Click on OK and the New Configuration window will pop up. In the New Configuration window, click on the Use Template button and choose the spectre template from the drop down list, and click OK.
In the Hierarchy Editor, navigate to Top Cell setup and set "Library", "Cell", and "View" options to be "stat_example", "testBench", and "schematic", respectively, which applies the netlist partition configuration on the circuit schematic design. Click on the Recompute the hierarchy button to update the setup.
The Global Bindings setup configures hierarchy expansion rules for circuit netlist. In this example, add "INTERCONNECT" to the end of View list and set Stop List to "spectre".
[[Note:]] Users do not need to create a HED config for optical netlist. Optical netlister automatically reuse the View List of config, in order to keep a consistent hierarchy expansion for both electrical netlist and optical netlist. Please refer to the Co-simulation setup step in the Electro-optical co-simulation (CoSim) using Spectre-INTERCONNECT interop page.
HED config determines connecting nodes between electrical domain and optical domain. Please refer to the Electro-optical co-simulation (CoSim) using Spectre-INTERCONNECT interop page for more details.
Setup ADE maestro
Click on the ADE Explorer button in the Hierarchy Editor window and select Create New View in the pop-up Launch ADE Explorer window to bring up the Create New ADE Explorer View window.
Click on OK and the ADE Explorer Editing window will pop up.
Set Simulator
In ADE Explorer Editing window, set the simulator to spectre by going to:
Setup -> Simulator
Open Design in Tab
Right click on the "stat_example_testBench_1" entry and select Open Design in Tab.
Set Analyses
Then go back to maestro tab and set the analyses by going to:
Analyses -> Choose
Set the analysis type to tran and set the simulation Stop Time to 5.2 ns. Check the Enable box.
Set simulation outputs
Add a result to the maestro window by going to:
Outputs -> Add -> Signal
and set its name to "output". Double click on the "Details" entry to bring up the schematic design again, then select the "ele_an" port of the photodetector as the output.
Save the configured ADE Explorer window. The configured ADE explorer window is shown below:
Set co-simulation properties
To setup the co-simulation properties for INTERCONNECT, users can go to
Setup -> INTERCONNECT -> Co-simulation Setup
A “INTERCONNECT Co-simulation setup” window will pop up. Please refer to the Electro-optical co-simulation (CoSim) using Spectre-INTERCONNECT interop page for more details on the co-simulation settings. For this example, the co-simulation setup is as shown below:
Set high-performance option
Set the high-performance option by going to
Setup -> High-Performance Simulation
and check the Simulation Performance Mode option as Spectre.
Set job policy
Then set the job policy by going to
Setup -> Job Setup
and check the Job Control Mode option ICRP.
Setup design kits
Setup the design kits and cdsLib path by going to:
Setup -> INTERCONNECT -> Design Kit Setup
and specify the path to the cds.lib file created during the installation of EPDA environment. For Design Kit 1, specify the directory where the INTERCONNECT design kit was installed (this directory should contain the stat_library.lib.x file).
Setup model library
Set the model library by going to:
Setup Model Libraries
and in the Model Libraries Setup window, under Model Files click <Click here to add model files> and select the stat_library.sec file in the directory where the INTERCONNECT design kit was installed. Select nominal from the dropdown list in the Section column for this Model File. stat_library.sec file lists all the available statistical variants for ADE to trigger statistical analysis.
Note:
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Netlist, run and visualize result
Nominal simulation
With the model library Section and design kit data set to nominal, we are now ready to netlist and run the nominal co-simulation. In the ADE Explorer Editing window, create/update the netlists of the circuit by selecting:
Simulation -> Netlist -> Create
Once the netlist can be generated successfully, perform co-simulation by:
Simulation -> Run
ADE will call out INTERCONNECT engine to perform optical simulation in backstage. User should see a pop-up log window indicating the status of the simulation and the time step information will be shown and updated in the “spectre.out” window, as shown in the figure in below.
When finish running, the nominal result collected at photodetector "ele_an" port will pop up.
Monte Carlo analysis
To set up the Monte Carlo Analysis, begin by checking the Monte Carlo Sampling option in the Setup Panel on the left-hand side of the ADE Explorer window. Underneath the Monte Carlo Sampling check box, select Click to Open Setup Form. Specify the number of trials to run in this window and click on OK. In this example we run 20 trials. Then click to expend the Advanced - Show All Options section and check the Save Waveforms (Simulation Data) option to save the waveforms for all the simulation iterations.
Then go back to the ADE Explorer Window and use the method described in the Setup design kits section and Setup model library section to reconfig the model library Section and design kit data to statistical.
Netlist and run the simulation as described in the Nominal simulation section. When running the Monte Carlo analysis the process will be shown at the bottom of the ADE Explorer window and user can see the details of the running process of all the trails with the Detail option in the Results tab.
The photodetector current MC analysis result will be plotted automatically when the simulation is finished running.
Corner analysis
To set up the corner analysis, begin by unchecking the Monte Carlo Sampling box and checking the box for Corners in the Setup Panel on the left-hand side of the ADE Explorer window. Underneath the Corners check box, select Click to add corner. This will open the Corners Setup window.
Under Model Files, select Click to add. Select the stat_library.sec file from the CML installation destination folder. This file provides a list of corner options for this statistical CML.
Click on the Add New Corner button to add two more corners "C0" and "C1". Click <section> in the “C0” column and select “corner_1” from the dropdown list, and make sure the checkbox is checked. Do the same for the “C1” column and select “corner_2”. The final Corner Setup window should look like below.
Then go back to the ADE Explorer Window and use the method described in the Setup design kits section and Setup model library section to reconfig the model library Section and design kit data to nominal. This step sets the statistical variant for the ‘Nominal’ point of the Corners Setup shown in the previous step.
Netlist and run the simulation as described in the Nominal simulation section. When running the Corner analysis the process of the simulations will show at the bottom of the ADE Explorer window and in the Results tab.
The photodetector current output results will be plotted automatically when the simulation is finished running. The nominal result is the expected result for the design, and the corner_1 and corner_2 results estimate the corner cases of the result given the model statistical variant, as shown below.