Custom Instrument Tutorial - Defining Base Options for the Instrument

From the design schematic, right-click on the symbol for the Custom Instrument and choose Configure from the context menu. The Custom Instrument Configuration dialog appears, with the Signals tab active by default (Figure 1).

As customization of the instrument extends to the title used at the bottom-right of the instrument's panel, let's change it. Enter Example Instrument in the Title field.

We will keep the default settings to show the Options and Synchronize buttons on the panel.

The bitmap used to represent the instrument in the Soft Devices JTAG chain of the Devices view can also be cusomized. Enable the Use Custom Bitmap option and click on the Select Bitmap button. Use the subsequent dialog to navigate to the \Examples\NanoBoard Common\FPGA Hardware\Custom Instrument Design folder of the Altium Designer installation and open the ExampleInstrumentIcon.bmp file.

The Configuration File region of the tab is where the file, into which all configuration information will be stored, is specified. Storage of configuration information in a separate file (*.Instrument) allows for portability of customized instruments between projects and installations – why use someone else's instrument, when you can take your favorite with you!

Let's go ahead and specify the name and location for our new configuration file.

Click on the folder icon to the right of the Configuration File Name field. Use the Save Configuration File To dialog that appears to save the configuration file as Custom_Instrument_Example.Instrument, in the same folder as the parent project.

When a custom instrument is detected in the Soft Devices JTAG chain, there are two methods by which Altium Designer can access the relevant configuration information:

• From Project – the configuration information is retrieved from the corresponding .Instrument file for the instrument, which resides alongside the project file. The project must be open in order to show the instrument from the Devices view.

• From FPGA – the configuration information is downloaded with the design to the physical device, and stored in Block RAM. It is retrieved directly from here and the project need not be open.

For this tutorial, let's have the configuration for the instrument stored in the target physical FPGA device. Enable the From FPGA option in the Configuration Retrieval region of the tab.

The Signals tab of the dialog, now fully configured for our requirements, should look like the image in Figure 2.