Testing and Debugging

Use the following links to browse through the frequently asked questions relevant to this area of soft design. For more in-depth, visual answers to commonly posed questions, use the links to the corresponding training videos, listed on the right.

Why can't I see the Soft JTAG chain when I have multiple boards in the system?

The FPGA design environment supports the simultaneous development of FPGAs on multiple NanoBoards or connected user boards. If you have multiple FPGA devices present in the Devices view, you must have a valid design downloaded into each device in order to use the Soft JTAG chain. If one FPGA in this chain includes soft (Nexus-enabled) devices and others do not, each design that does not include soft devices must include the two Soft JTAG implementation components – NEXUS_JTAG_PORT and NEXUS_JTAG_CONNECTOR. This is because the Soft JTAG chain must route through all target FPGAs, even if an FPGA does not make use of it.

Why does the custom bitmap i'm using for a Custom Instrument component not display properly in the Devices view?

When creating a customized bitmap it is important to keep in mind that the Devices view will only display an image that is 80x70 pixels in size. Larger than this and it will be cropped, smaller and it will be centered within these bounds accordingly.

Why can't I access an embedded Custom Instrument using Altium's Instrument Dashboard, or the Viewer Edition of Altium Designer?

If you intend to provide access to a Custom Instrument using either Altium's Instrument Dashboard or the Viewer Edition of Altium Designer, you must ensure the From FPGA method of retrieval is specified when configuring the instrument. This option is defined on the Signals tab of the Custom Instrument Configuration dialog.

How can I directly monitor/control part of a bussed signal within my Custom Instrument GUI?

In the value field for the SignalName property, simply select the required signal, then modify the index accordingly. For example, consider an input signal, Data_In[7..0], which is wired to a Custom Instrument on the schematic. On the customized instrument panel, we might want to monitor the individual bits of this signal, using eight Progress Bar controls. Starting with the left-most Progress Bar control, you would simply select each control in turn and set the SignalName property to assign the corresponding signal line of the Data_In[7..0] input. So set Data_In[7] for the leftmost control, then Data_In[6] for the next control, through to Data_In[0] for the right-most control.

Example of 'splitting' a signal over multiple instrument control objects.

Can I use any scripting language to write the event handling code for a Custom Instrument?

No. Only DelphiScript is supported.

How do I get an instrument control on my Custom Instrument GUI to initialize to zero/minimum value?

If the instrument control is being used to monitor an input, use the control's Position or Value property and set to either '0' or the same value as the control's MinValue property, in accordance with design requirements.

If the instrument control is being used to control an output, set the initial value for the signal on the Signals tab of the Custom Instrument Configuration dialog.

I'm using the TInstrumentLEDsPanel/TInstrumentLEDDigits/TInstrumentNumericPanel control in a Custom Instrument GUI, but when I access the run-time panel, the control is not editable – why?

When using any of these three instrument controls – linked to an output signal – the display will only be editable provided the UseDefaultDigitClick property is enabled.

I have a Crosspoint Switch module in my design. What happens to unconnected output blocks?

An unconnected output block will retain and output its previous value, only if it has had a prior connection to it.

Where do I access the live moitoring of physical device pins?

The state of the FPGA pins can be monitored, in real-time, using the device's associated JTAG Viewer panel. From the Devices view, double click on the physical device to access the Instrument Rack - Hard Devices panel. Then click on the JTAG Viewer Panel button. Ensure that the Live Update option is enabled.

Enable the Live Update option in the device's associated JTAG Viewer panel to monitor the state of the FPGA pins in real-time!

Why do my schematic probe directives not update in real time?

For the pin state to be updated in real-time on the schematic, the source FPGA design must be downloaded to the physical FPGA device and the associated JTAG Viewer panel for that device must be open and remain open.