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SerDes Toolbox Interface for SiSoft Quantum Channel Designer and QSI Software

This example shows how to use SerDes Toolbox™ Interface for SiSoft® Quantum Channel Designer® and QSI™ Software support package to test IBIS-AMI SerDes models developed in Simulink® using SerDes Toolbox, in SiSoft Quantum Channel Designer (QCD) or Quantum Signal Integrity (QSI) software. You can transfer the data required to reproduce a QCD or QSI test case back to Simulink for debugging and refinement. You need SiSoft 2018.07-SP4 or later software to run this example. You must also have installed the SiSoft Link app provided with the support package.

SerDes Development Flow

SerDes model development begins with the SerDes Designer app. The app exports a Simulink model with transmitter (Tx) and receiver (Rx) SerDes models and a testbench to simulate and further develop the SerDes designs. Test the models in QCD or QSI to verify proper IBIS-AMI model operation in a target EDA tool. Due to the high performance of IBIS-AMI executable models, run many simulations to verify the full range of model capabilities, testing with all possible AMI parameters and a variety of stimuli and interconnect channels. Replicate the simulation cases warranting closer inspection in Simulink to reproduce and debug the test. Repeat this cycle as many times as needed, updating the QCD/QSI project and Simulink model.

Create SerDes Toolbox System Model

Open the SerDes Designer app from the Apps toolstrip. Use the app to quickly prototype and statistically analyze a SerDes system with a Tx and an Rx.

Add blocks from the Blocks gallery to the Tx and Rx sides. If you change the block parameters, the statistical eye display shows the performance changes. Click on Export SerDes System to Simulink from the Export dropdown menu to create a Simulink model for the system.

Prepare SerDes Simulink Model for QCD/QSI

The SiSoft QCD and QSI software requires IBIS models to simulate the Tx and Rx of your system. Use the Open SerDes IBIS-AMI Manager button in the Configuration block to produce the IBIS files. In the Export tab of the SerDes IBIS-AMI Manager dialog box choose a target directory and click the Export button to create the set of IBIS files.

Create QCD Project

Click the SiSoft Link icon from the Apps tab in the MATLAB toolstrip to open the SiSoft Link app.

If your SerDes system model is open in Simulink, it is listed in the Simulink Model dropdown menu in the SiSoft Link app. Click the Refresh button if your model is not listed. Set the QCD/QSI project dropdown menu to New QCD project (create) and click Create QCD. If there are unresolved issues regarding the selected Simulink model, Create QCD button remains disabled.

Choose a folder in which the QCD project resides and a name for the project folder. The folder path and project name must not have spaces. If you have not yet used SiSoft Link to create a project, the system asks you to locate the folder containing your SiSoft software. A report window appears and QCD opens executing a script produced by SiSoft Link. When script execution finishes, the QCD project interface is renamed after your SerDes system model, with a single sheet sheet1.

The following data are copied from Simulink to QCD:

  • The QCD interface has the same name as the Simulink model.

  • QCD has one sheet, sheet1.

  • All IBIS files is copied into the QCD project si_lib/ibis folder.

  • All Tx and Rx model parameter values from Simulink is set in the QCD solution space.

  • Simulation parameters are set: UI, Samples_Per_Bit, and TargetBER.

Create QSI Project

To create a QSI project, set the QCD/QSI project dropdown menu to New QSI project (create) and click the Create QSI button. The process is otherwise similar to that for QCD. Typically, IBIS-AMI models are used in QSI for analysis of single-ended DDR4/5 DQS signals with equalization. If that is the case, double click the Configuration block in the Simulink model to open it, and set Signaling to Single-ended before creating the QSI project.

For QSI the following simulation parameters are set:

  • The QSI interface has the same name as the Simulink model.

  • QSI has one sheet, sheet1.

  • All IBIS files is copied into the QSI project si_lib/ibis folder.

  • All Tx and Rx model parameter values from Simulink is set in the QSI solution space.

  • Simulation parameters are set: UI, Samples_Per_Bit, and TargetBER.

  • The Tx rise_time is copied from the typical corner value in the IBIS file.

  • Time_Domain_Stop is set to Ignore_Bits + 20,000 UI.

  • Record_Bits is set to 100 and Record_Start is set accordingly.

Import QCD or QSI Simulation Data into Simulink

After simulating in QCD or QSI, you can import data to reproduce a simulation in Simulink. You must select the project in the QCD/QSI project dropdown menu. Click the Browse... button to choose a desired QCD or QSI project if it is not listed in the QCD/QSI project dropdown menu.

The following data are copied from QCD/QSI to Simulink, as enabled by the Import section checkboxes:

  • All Tx and Rx model parameter values from the selected simulation are set in corresponding blocks in the Simulink model.

  • Modulation, SymbolTime, and SampleInterval are set in the Configuration block.

  • The time domain stimulus pattern is set in the Stimulus block, even if only statistical simulations are run in QCD/QSI.

  • The channel impulse response from QCD/QSI is set in the Analog Channel block.

A report is generated giving the details of the import.

Update QCD or QSI with New Data from Simulink

To support iterative development, selectively update a QCD or QSI project with data from Simulink. When a QCD or QSI project path is selected in QCD/QSI project dropdown menu, the Create QCD (or Create QSI) button becomes Update QCD (or Update QSI). The checkboxes above the button are enabled to choose the data to be updated. If Update .ibs file is checked, the checkboxes for .ami files and .dll/.so files are forced on, since importing the .ibis file in QCD or QSI always imports the other files along with it.

Clicking Update QCD (or Update QSI) runs the QCD (or QSI) to open the project and makes the changes. To avoid conflicts, you must close the project before updating it.

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