CHAPTER 2 Getting Started

Overview 2-3

Starting DAI Signalscan 2-3

Invoking in UNIX 2-4

Invoking in Windows NT 2-5

A Quick Tour of DAI Signalscan 2-6

Opening the SST2 Database 2-6

Opening the Design Browser 2-7

Displaying Waveforms 2-8

Viewing Sequence Time 2-9

Creating a Register Page 2-11

Creating Events 2-12

Tracing Variables 2-13

Mnemonic Mapping 2-15

Exiting DAI Signalscan 2-16

Overview

This chapter introduces the basic features of DAI Signalscan. In this chapter you will use the Verilog design file simple.v and the SST2 Database files simple.trn , simple.stc , and simple.dsn . These files are available as part of your distribution.

DAI Signalscan has two modes of operation: a post-simulation data analysis mode and an interactive simulation mode. This chapter introduces only the post-simulation mode.

In the example used in this chapter, the post-simulation SST2 Database is saved in the files simple.trn and simple.dsn . Information on generating the SST2 Database from the simulation is discussed in "Interfacing DAI Signalscan to Your Verilog Simulator", "Using Signalscan and VHDL", and "Analog Features".

Since this chapter deals with the post-simulation data, use of the Source Code Window is not explained here. Refer to "Working With Source Code" for details on how to use the Source Code Window.

Starting DAI Signalscan

Signalscan attempts to execute an optional Do-File, .signalscanrc , from the current directory when it is first invoked. If it cannot find a .signalscanrc file in the current working directory, it looks in your home directory.

Copy the files simple.trn , simple.stc , and simple.dsn into your current working directory. These sample SST2 Database files are included in the Signalscan distribution ( $DAI_HOME/signalscan- version /examples ). Make sure the environment variable $DAI_HOME is set to the directory where Signalscan is installed. Then invoke Signalscan as described in either "Invoking in UNIX" or "Invoking in Windows NT" below.

Invoking in UNIX

To invoke Signalscan, enter the following command on the command line:

where input_file_name is a .trn file, as in the following example:

or input_file_name is a .do file if you specify the -do option, as in the following example:

To see a list of the options that can be used with Signalscan, enter:

Table 2-2 describes these options:

Invoking in Windows NT

Use any of the following methods to invoke Signalscan in Windows NT:

• · Double-click on a .trn file.
• · Select the Signalscan version you want from the DAI Signalscan program group on your Start menu.
• · Enter signalscan at the command prompt. You will have to enter the entire pathname if you have not updated your PATH .

A Quick Tour of DAI Signalscan

When you invoke Signalscan, the Control Window (Figure 2-1) is displayed on your screen.

Figure 2-1. DAI Signalscan Control Window

Opening the SST2 Database

You must open the SST2 Database that you want to use for your analysis.

To open a design file:

1. 1. Click the OpenSimFile button in the Button Bar.

An Open File dialog box is displayed. By default the *.trn filter is used to display the list of .trn files available in the current directory. To list other files, edit the Filter field and click the Filter button.

2. 2. Select the file simple.trn by double-clicking on the file name.

The design information is now loaded into Signalscan. You can view the design hierarchy and select signals to view using the Design Browser Window.

Opening the Design Browser

To open the Design Browser:

• · Click on the DesBrows button in the Button Bar.

The Design Browser Window (Figure 2-2) is displayed. The Current File field displays the file name simple.dsn . This is your current design file. The Current Scope field is empty, since you are at the top level scope of your design. The instance names of modules instantiated in the current scope are shown in the Scopes Pane and the variables in this scope are shown in the Variables Pane.

Figure 2-2. Design Browser

To descend a level in the design hierarchy:

• · Using the left mouse button, click on an instance name in the Scopes Pane.

This brings you down a level in the design. The scopes and variables for this level are now displayed.

To return to a previous level in the design hierarchy:

• · Click the CDUpScope button.
• · Create a bookmark (enter Ctrl+k or select the Edit>Create>Bookmark menu option) and then select it.
• · Using the right mouse button, click anywhere in the Scopes Pane.

If there are any variables available for the scope, they are then displayed in the Variables Pane.

As you traverse through the design hierarchy, the Current Scope field at the top of the Design Browser Window is updated with the full path of the current scope.

Displaying Waveforms

Variables and their values in the design file can be examined in a number of ways using Signalscan. One way is to display the value of the variable as a signal in the Waveform Window. This section shows you how to copy variables from the Design Browser Window to the Waveform Window.

To view all the variables in the current design:

1. 1. In the Scopes Pane, make sure you are at the top of the design hierarchy.

The Current Scope should be blank and modules "Analog" and "Top" listed. Use the hierarchy traversal information above to return to this scope if you are not already there.

2. 2. Click on the GetDeepAll button.

This gets all the variables at all the different levels of your design, from the current scope down to the lowest level scope.

To add the variables to the Waveform Window:

• · In the Design Browser Window, click on the AddToWave button in the button bar.

The Waveform Window is displayed (Figure 2-3). The variables are listed in the Names Pane of this window; their waveforms are displayed in the Waveform Pane.

Figure 2-3. Waveform Window

Viewing Sequence Time

Sequence Time allows you to view and debug activities that conceptually take place at the same instant, but that are actually executed in a specific order by the simulator. Sequence Time works with another feature, Multivalue Indication, which marks places where a variable has changed value more than once at the same simulation time (see Figure 2-4). Multivalue Indication points on a waveform are identified by pink dots.

Figure 2-4. Sequence Time in the Waveform Window

To expand a time point to see the true sequential ordering of events:

1. 1. Use the left mouse button to click on a pink dot in the Waveform Window.

This positions Cursor1 at this point.

2. 2. Select View>Expand Sequence Time>At Cursor1 .

The time point expands to show the sequence of all the events that take place at that point in time, as shown in Figure 2-4. It is likely the expanded time will extend beyond the right hand end of the Waveform Window. Click on ZoomOutX to condense the waveforms so that all of the sequence time area is visible.

Creating a Register Page

To create a Register Page (Figure 2-5):

Figure 2-5. Register Page

1. 1. In the Names Pane of the Waveform Window, select the first four variables.

To select multiple variables, press the left mouse button on the first variable in the list, drag the mouse over the variables you want to select, and then release the mouse button.

2. 2. In the Waveform Window, select Edit>Create>Register Page .

A Register Page dialog box is displayed.

3. 3. Type rpage1 as the register page name and press Return .

A Register Page, named rpage1 , is created and is displayed in the Register Window. The selected variables are listed in the Register Pane of this window.

The register values are displayed for the time indicated by the TimeA cursor. In the Waveform window, this cursor can be moved by using the left mouse button to drag its label in the Times Pane or by double-clicking on the time of interest in the Waveform Pane. (Double-clicking also changes Cursor1.)

To move a selected variable:

1. 1. In the Register Window, click the left mouse button on the variable dir to select it.

Move the variable around the Register Page by holding the left mouse button down while moving the mouse.

2. 2. Position the variable at a particular location on the Register Page by releasing the mouse button.

The variable remains highlighted on the Register Page.

The Register Window can display multiple Register Pages. You can switch between the pages by clicking on the Register Page name in the Multi-List Pane on the right-hand side of the Register Window.

Creating Events

An event is a query template consisting of variables with a certain configuration of values.

To create an event:

1. 1. In the Waveform Window, click the left mouse button to select the variable in2[3:0] from the Names Pane.
2. 2. Select Edit>Create>Event to create the event.

An Events Window (Figure 2-6) is displayed.

3. 3. Click the Paste button in the Events Window.

The event event001 is created using the selected variable.

Figure 2-6. Events Window

To change the value of a variable in an event:

• · Click on the value part of the variable.

Change the value to 3.

You can use an event to search for occurrences of this event in your design in the Waveform Window.

To search for an event in the Waveform Window:

1. 1. In the Waveform Window, select the down arrow in the top right corner of the Multi-List Pane on the right-hand side of the window (to the right of the title Groups in Figure 2-3).
2. 2. Select Events from the pop-up list.

A list of the currently defined events is displayed.

3. 3. Click your left mouse button on an event name.

Cursor1 is moved to the next occurrence of that event.

You can toggle between the forward and backward search directions of your Event search by clicking on the >> button next to the Events title in the Multi-List Pane of the Waveform Window.

Tracing Variables

To aid in debugging variables with incorrect values, Signalscan lets you create schematics on the fly that show you the drivers of a selected signal. Use the Schematic Tracer Window to do this. You can select a signal from any window and get a graphical view of its drivers in the Schematic Tracer Window.

To trace a variable in your design:

1. 1. In the Waveform Window, click your left mouse button on a[3:0] in the Names Pane.
2. 2. Select Control>Go To>Schematic .

The Schematic Tracer Window (Figure 2-7) is displayed with the trace information for the selected vector at TimeA.

Figure 2-7. Schematic Tracer Window

To go to the next value change of the vector sumOutStructure[4:0] , enter Ctrl+n in the Schematic Tracer Window.

To traverse the design hierarchy, double-click on modules or signal names. You may need to use the scroll bars to get to the appropriate signals.

To trace the value of a pin, double-click on that pin.

To go down into a level of hierarchy, double-click in the instance aStructure of the Adder4Structural module. The internal structure of aStructure is displayed in a new Schematic Tracer.

Mnemonic Mapping

Signalscan allows you to define mnemonics for bus values, and to display those mnemonics in the Waveform, Schematic Tracer, and Register Windows. Figure 2-8 shows the Define Mnemonic Mapping dialog box.

Figure 2-8. Define Mnemonic Mapping Dialog Box

To open this dialog box:

• · Select Options>Define Mnemonic Maps .

The dialog box opens with a default name, and one value/mnemonic pair that maps Default to <`h> (hexadecimal). The Default value cannot be removed, but the mnemonic can be changed.

To enter a new value/mnemonic pair:

1. 1. Click anywhere in the Value pane.

A text cursor appears at the next new entry point.

2. 2. Enter the value.
3. 3. Press Tab to move to the Mnemonic pane (or click next to the mnemonic entry point).
4. 4. Enter the mnemonic for that value.

In the above example, the value 1 is mapped to the word ONE . The mnemonic may include one of <`b> (binary), <`o> (octal), <`d> (decimal), <`h> (hexadecimal), <`s> (signed decimal), or <`a> (ascii).

Once the mnemonic mapping is created, it can be applied to buses:

1. 1. Select the appropriate bus (in the Waveform Window, for example).
2. 2. Select Format>Variable Radix .

The mnemonic mapping(s) appear on the list of options.

3. 3. Select a mapping to apply it to the selected signal.

Selecting the map number in the leftmost column allows individual mnemonic/value pairs to be copied, cut, or deleted. The Default pair cannot be deleted.

To create a new map, click on the New Map button. To delete a new map, click on the Delete Map button. Use the Value Radix pull-down menu to set the display radix of the mapping window. Use the Mnemonic Map Name pull-down menu to view a list of available maps, select a map from the list, or change a map name. To change a map name, select that name and then enter the new name in the Mnemonic Map Name field.

Exiting DAI Signalscan

You now should be familiar with the user interface and have a good idea of the basic operations that you can perform in Signalscan.

To close the session or exit from Signalscan:

1. 1. Select File>Exit from any window that has a File menu.

A dialog box is displayed showing the message: "Are you sure you want to exit DAI Signalscan?"

2. 2. Click Exit .

See also "Saving and Restoring Your Configuration".