www.coware.com

1

Getting Started

Introduction

The CoWare® Signal Processing Worksystem (SPW) provides tools that you can use to interactively capture, simulate, test, and implement a broad range of digital signal processing (DSP) designs. Typical applications include digital communication systems, image processing, radar systems, control systems, digital audio, and high-definition television.

This manual contains a collection of tutorial lessons to help you get started using SPW. Each chapter presents a software component of SPW (such as the Block Diagram Editor or Signal Calculator) or an application example for you to work on. You learn about the software by using it as directed in the tutorial.

The tutorial lessons are not intended cover all SPW topics in full detail. For more information on a particular program module, consult the applicable manual such as the BDE User's Guide or Signal Calculator User's Guide.

Tutorial Manual Chapters

The first six tutorial chapters cover the core modules of SPW. The tutorial chapters should be done in order, from Chapter 1 through Chapter 6. This set of six chapters is a prerequisite for the remaining tutorial chapters and for the tutorials found in other SPW product manuals.

Chapters 7 through 11 are independent lessons. You can choose to do only the tutorial lessons that you need, in any order. The SPB-C chapter requires installation and licensing since it is an SPW add-on product. An evaluation license may be available for the optional product; see your CoWare sales representative for details.

Chapter 12 lists the tutorials available in other SPW-related product manuals.

Before You Start

Before you can start the tutorial, SPW must be installed and licensed at your site. If you have difficulty in getting SPW started, see your system administrator or SPW site administrator for assistance, or see the SPW User's Guide for setup information.

The File Manager

The File Manager is a unified tool that lets you manage SPW data files. To invoke the File Manager, type the command "spw" at the operating system prompt.

Your File Manager window should resemble the one shown in Figure 1-1. The command icons and list box entries might vary, depending on the optional products installed at your site.

Figure 1-1  File Manager Window

The list box lists the data files of the type specified by the Browser Filter option button (BDE Models, SigCalc Signals, or FDS Filters). The command icons along the left side of the File Manager window let you invoke the SPW program modules.

SPW Libraries and Files

SPW creates many types of data files such as block diagrams, signal files, simulation run files, and filter designs. All such data files are stored in directories called libraries. When you create a new library, you specify its UNIX directory path. After that, you do not need to be concerned about where the library resides. To gain access to a data file, you only need to specify the library name and file name.

For BDE files, there are two sets of parallel names called logical grouping and logical file names. For example, the tutorial model used later in this chapter has both a logical grouping (>Misc>LMS Example) and a logical file name (spb_demo/lmsdemo.system). A logical grouping name consists of a series of words separated by right-pointing angle brackets, whereas a logical file name consists of three names in the form of library/cell.view.

Create a Library

In order to perform the tutorial procedures in the remaining chapters of this manual, you need to create one or more libraries in which to store your SPW data files. To create such a library, do the following:

  1. In the File Manager window, execute the command: 
    2. Libraries-Setup 
 
    
This displays the Library Setup dialog box shown in Figure 1-2. The Create New Library button is toggled on by default.
Figure 1-2  Library Setup Dialog Box

  1. Click on the Next button.

    2. This displays the Create New Library dialog box shown in Figure 1-3. The Create Unmanaged Library button is toggled on by default.

Figure 1-3  Create New Library Dialog Box

  1. Click on the Next button.

    2. This displays the Create Unmanaged Library dialog box shown in Figure 1-4.

Figure 1-4  Create Unmanaged Library Dialog Box

  1. In the Library Name field, enter a name for your library. For example, if your name is Joe, you could enter the name "joelib". In the text of the tutorial manual, the name yourlib is used to represent the name of your library.
  2. In the Path to Library field, specify the UNIX directory path where you want the library directory to be created, up to (but not including) the name of the library itself. For example, you can enter the path of your home directory. Click on the Options ... button to choose from a list of directories.
  3. Click on the OK button.

The File Manager creates the library in the specified directory path. The system message area of the File Manager displays a message indicating that the library was added.

Design Management

In the process of creating a new library, you specify whether you want to create an unmanaged or managed library. In the absence of design management, SPW maintains one current revision and a single backup (.bak) revision of each design.

If you are familiar with RCS or ClearCase design management, you can choose to use one of these tools for managing your data files. Then you can maintain a database of design revisions using the DM commands in the File Manager. However, using RCS or ClearCase is beyond the scope of this manual. See the SPW User's Guide for information on design management.

Library List

The list of accessible libraries is contained in a file called ~/spwfiles/cds.lib (where the tilde character represents the path of your home directory). Each user has a cds.lib file that is separate from those of other users, so the list of accessible libraries can vary from user to user. You can gain access to an existing library by using the Use Existing Library option in the Library Setup dialog box.

Quick Simulation Example

In the following procedure, you display a prebuilt demonstration system design using the Block Diagram Editor (BDE), simulate it with the Simulation Program Builder (SPB-I), and display the results in the Signal Calculator (SigCalc).

Display the Demonstration Model

  1. In the list box of the File Manager, find the logical grouping name Misc>. Use the scroll bar to scroll the list if needed. The names are listed in alphabetical order.
  2. Double-click on Misc> in the list box.

    3. This selects the Misc> logical grouping and displays its members in the list box. The Search field shows you the hierarchical path to the current list.

  3. Double-click on LMS Example in the list box.

    4. After a brief delay, the File Manager displays a BDE design window containing the selected system model, >Misc>LMS Example, as shown in Figure 1-5.

Figure 1-5  LMS Example Block Diagram

This system uses three different Least Mean Squared adaptive filters, each operating as a notch (bandstop) filter to remove a 60-Hz sine wave "hum" signal added to a speech signal. The purpose of this system is to compare the performance of the three filter algorithms.

Simulate the Demonstration Model

  1. In the BDE design window, execute the following command: 
    2. Tools-Simulation Manager 
 
    
This displays the Simulation Manager window as shown in Figure 1-6.
Figure 1-6  Simulation Manager Window

Before you can run a simulation, you must save the current simulation setup into a "toolrun" data file.

  1. In the Simulation Manager window, execute the following command: 
    2. File-Save As 
 
    
This displays the dialog box shown in Figure 1-7.
Figure 1-7  Simulation Manager File Save As Dialog Box

  1. In the New logical name field, replace the library name spb_demo with the name of your own library:

    2. demo_out/lmsdemo.toolrun

Important icon By default, the demo_out library is attributed to the $SPW_HOME/site_data/demo directory. You can confirm this location by viewing the cds.lib file available in the $SPW_HOME/CDS/share directory. The demo_out library can be viewed and its contents overwritten, by any user. Therefore, as soon as you perform this task, ensure that the lmsdemo/toolrun directory generated in that library, has your login id attributed to it.

  1. Click on the OK button.

    2. The name of the toolrun view is displayed at the top of the Simulation Manager window.

Note: A "view" is an SPW data file stored under the naming convention "library/cell.view".

  1. Click on the Start button.
  2. Allow the simulation to run to completion. Look for a full-length green bar in the status line, as shown in Figure 1-8.
Figure 1-8  Simulation Manager Status Line and Messages

View the Simulation Results

Before viewing the simulation results using SigCalc, ensure that the generated signal files have your user id attributed to them. These signal files are generated in the demo_out library.

  1. In the Simulation Manager window, click on the SigCalc button.

    2. This displays the simulation Files Preview dialog box.

  2. In the dialog box, click on the OK button.

    3. This displays the simulation results in the SigCalc window, as shown in Figure 1-9.

Note: Your view of the simulation results may be somewhat different from what is shown in the figure, depending on your previous option settings (such as the signal window size).

Figure 1-9  Simulation Results in SigCalc

The first three signals are designated S1, S2, and S3. S1 and S2 are the input signals, a speech signal and a 60-Hz sine wave "hum" signal. S3 is a simulation output signal, created by adding the two input signals. This signal is 1000 data points long because the simulation ran for 1000 iterations.

  1. Using the scroll bar, scroll down the signal display to view the last three signals.

    2. The last three signals are designated S4, S5, and S6. These are the outputs of the three notch filters in the block diagram.

    To change the viewing scale of an output signal, do the following:

  2. Click on the S4 button at the upper-left corner of the S4 signal display frame.

    3. This selects and highlights signal S4.

  3. In the SigCalc window, execute the following command:
    4. View-Change Scale-Override 
 
    
This displays the dialog box shown in Figure 1-10.
Figure 1-10  Override Scale Dialog Box

  1. Change the High Axis Value to 0.1 and the Low Axis Value to -0.1, then click on the OK button.

    2. SigCalc redraws signal S4 using the specified new scale.

Close the SigCalc and Simulation Manager Windows

  1. In the SigCalc window, execute the following command: 
    2. File-Close
  2. In the dialog box, click on Yes to confirm that you want to close and remove SigCalc.
  3. In the Simulation Manager window, execute the following command: 
    4. File-Exit
  4. In the dialog box, click on Yes to confirm that you want to close and remove the Simulation Manager.

You will learn more about the capabilities of BDE, the Simulation Manager, and SigCalc in Chapters 2 through 6.

At this point, you can continue with the next tutorial chapter, which teaches you how to use BDE to create block diagrams. If you would prefer to continue at another time instead, execute the File-Close command in the BDE design window and then in the File Manager window to close those windows.

CoWare
 CoWare's Web Site
Phone: 1-888-269-2738
CoWare Customer Support