Logic Analyzer

To visualize data in the Logic Analyzer, you must enable signal logging for the model. (Logging is on by default.) To enable signal logging, open Model Settings from the toolstrip, navigate to the Data Import/Export pane, and select Signal logging.

When you open the Logic Analyzer, all signals marked for logging are listed. You can add and delete waves from your Logic Analyzer while it is open. Adding and deleting signals does not disable logging, only removes the signal from the Logic Analyzer.

Open the Logic Analyzer and select a wave by double-clicking the wave name. Then from the Wave tab, set parameters specific to the individual wave you selected. Any setting made on individual signals supersedes the global setting. To return individual wave parameters to the global settings, click Reset.

1. Open the Logic Analyzer and select a wave by clicking the wave name.

   

2. From the Logic Analyzer toolstrip, click . The wave is removed from the Logic Analyzer.

3. To restore the wave, from the Logic Analyzer toolstrip, click .

   A divider named Restored Waves is added to the bottom of your channels, with all deleted waves placed below it.

   

1. Open the Logic Analyzer and select the Trigger tab.

   

2. To attach a signal to the trigger, select Attach Signals, then select the signal you want to trigger on. You can attach up to 20 signals to the trigger. Each signal can have only one triggering condition.

3. By default, the trigger looks for rising edges in the attached signals. You can set the trigger to look for rising or falling edges, bit sequences, or a comparison value. To change the triggering conditions, select Set Conditions.

   If you add multiple signals to the trigger, control the trigger logic using the Operator option:

   • AND - match all conditions.

   • OR - match any condition.

4. To control how many samples you see before triggering, set the Display Samples option. For example, if you set this option to 500, the Logic Analyzer tries to give you 500 samples before the trigger. Depending on the simulation, the Logic Analyzer may show more or fewer than 500 samples before the trigger. However, if the trigger is found before the 500th sample, the Logic Analyzer still shows the trigger.

5. Control the trigger mode using Display Mode.

   • Once - The Logic Analyzer marks only the first location matching the trigger conditions and stops showing updates to the Logic Analyzer. If you want to reset the trigger, select Rearm Trigger. Relative to the current simulation time, the Logic Analyzer shows the next matching trigger event.

   • Auto - The Logic Analyzer marks every location matching the trigger conditions.

6. Before running the simulation, select Enable Trigger. A blue cursor appears as time 0. Then, run the simulation. When a trigger is found, the Logic Analyzer marks the location with a locked blue cursor.

The Logic Analyzer enables you to bit-expand fixed-point and integer waves.

1. In the Logic Analyzer, click the arrow next to a fixed-point or integer wave to view the bits.

   The least significant bit and the most significant bit are marked with lsb and msb next to the wave names.

   

2. Click Settings, and then select Display Least Significant bit first to reverse the order of the displayed bits.

   

1. Open the Programmable FIR Filter model (dspprogfirhdl).

   

2. Open the Logic Analyzer and select the Trigger tab.

3. To add a trigger, in the toolstrip, select Attach Signals and attach the write enable Write En signal. An icon appears in front of the signal name to indicate it is attached to a trigger. The icon changes depending on the type of trigger.

4. Select Set Conditions and change the trigger condition for the Write En signal to Falling Edge. The trigger will show when the write enable signal was sent.

5. Attach the Write Done signal to the trigger. Keep the trigger condition for this signal as the default, Rising Edge. Now, the trigger will also show when the write was completed.

   If you open the Set Conditions drop down, you see an Operator field. This field appears when multiple signals are attached to the trigger. Change the operator to OR so that the trigger will show instances where a write was started or completed.

   

6. Set the Display Mode to Auto. With this setting, the Logic Analyzer marks all locations where the trigger conditions are met.

7. Select Enable Trigger and run the simulation.

   Each time the trigger conditions are met, the Logic Analyzer marks the time with a locked blue cursor. At each marked location, Write En is 0 and Write Done is 1. If you examine each location marked by a trigger, you can verify that each time a write is sent, it is also completed.