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CONTENTS

Speedgoat IO334 Example

Speedgoat IO334 Example — Example showcasing the analog input and analog output interface

Model Name

The model is called IO334_ad_da_hdlc.slx.

Supported Modules

  • IO334-325k

Required Toolboxes

The list of basic software requirements are provided in the prerequisites section of the Getting Started page.

Interfaces

The IO334 example uses the following interfaces:

User Blocks

The example does not utilize any user blocks.

Example

To test the HDL interface functionality, dedicated examples are included in the downloaded archive file. To open the examples, navigate to the corresponding folder. Note that the examples only test I/O channels for which the loopback test method is possible. The terminal board provided must be wired as described. Examples do not test I/O channels that require external hardware (for some examples a function generator or an oscilloscope is required), but running this example will still provide sufficient confirmation of the correct setup of this implementation. The examples only test interface channels which are provided by the base functionality of the I/O module. Please note that the examples provided have been color coded. The green colored subsystem (FPGA domain) is the part of the model which is actually compiled using HDL Coder and ultimately runs on the FPGA. The FPGA domain usually has a sample frequency in the range of 100 MHz and is set in the HDL Workflow Advisor (FPGA Synthesis Software Settings). The blue blocks (CPU domain) which surround the green subsystem are interfaces to the processor section of the model. The CPU domain usually has a sample frequency in the range of 1 kHz. The interrupt subsystem has been given another color (magenta), as its functionality is asynchronous to both the processor and FPGA. The interrupt source can be selected in the generated model in the Interrupt Setup block once the model has been run through the HDL Coder Workflow Advisor.

Open the example model by navigating to the folder containing the "*.slx" model file and double clicking the file. If the example is provided as a Simulink Project, navigate to the corresponding example folder and extract the Simulink project zip file. Then double-click the "*.prj" icon to open the project. After opening the project, open the model by double clicking the "*.slx" file. The model is shown as follows:

The DUT_ad_da subsystem is shown as follows:

Test Wiring

Use the following test wiring to ensure the correct functionality of the example provided.

From RJ45 JackTo RJ45 JackTested Functionality
AO 1:4AI 1:4AO channel 1/2/3/4 to AI channel 1/2/3/4
AO 5:8AI 5:8AO channel 5/6/7/8 to AI channel 5/6/7/8
AO 9:12AI 9:12AO channel 9/10/11/12 to AI channel 9/10/11/12
AO 13:16AI 13:16AO channel 13/14/15/16 to AI channel 13/14/15/16

Running HDL Workflow Advisor

Before the example can be deployed and run on the real-time target machine, you will need to run through the HDL Coder Workflow Advisor steps to actually generate HDL code and a FPGA bitstream using HDL Coder (FPGA Synthesis Software Settings).

New: Reference design parameters, set at step 1.2 now control which interfaces will be available to target in step 1.3 of the workflow. This has reduced the total number of reference designs, and the list of interfaces available. Please remember to select the front plug-in and rear plug-in setting that is appropriate for your module, as well as the Aurora settings that should be used for your model (if applicable). These additional reference design parameter settings are further described in the interface sections for which they are relevant.

New: Prior to running the workflow advisor, be sure to double click the Select Module block in the demo model. If one or more of your modules support the model (due to available interface compatibility), a pop-up will display prompting you to select the module you would like to target. If only a single module is installed, and providing it is compatible, it will be automatically selected when the box is double clicked.

Upon completion, a newly generated model containing the Simulink Real-Time interface subsystem appears. At first sight, this subsystem resembles the FPGA subsystem. However, inside, the Simulink algorithm has been removed and replaced with blocks that the real-time application will use to communicate with the FPGA during simulation execution. The newly generated model is now ready to be deployed to a real-time target machine. To download the FPGA bitstream and the Simulink model to the target, click the Build Model button on the Simulink Editor toolbar. The real-time application loads on the Speedgoat target machine and the FPGA algorithm bitstream loads on the FPGA. If you are using I/O lines, check that you have connected the lines to the external hardware under test. Please note that some example models do have Global Delay Balancing intentionally disabled. If an error is displayed about delay balancing in step 2.3 of the HDL Coder Workflow Advisor, it can be safely ignored by checking the Ignore warnings checkbox.

Real-Time Simulation Outputs

Once the model has been downloaded and the target application has started, double-click the scope to see the following traces:

  • The scope and corresponding SDI signals show the sine wave generated in the FPGA internally, emitted with the analog output, sampled with the analog input and finally logged via PCIe accesses