ANALOG DEVICES W4.0 Started Guide

W4.0
Getting Started Guide
Analog Devices, Inc. One Technology Way Norwood, Mass. 02062-9106
Revision 1.0, January 2005
Part Number
82-000420-01
a
Copyright Information
© 2005 Analog Devices, Inc., ALL RIGHTS RESERVED. This docu­ment may not be reproduced in any form without prior, express written consent from Analog Devices, Inc.
Printed in the USA.
Disclaimer
Analog Devices, Inc. reserves the right to change this product without prior notice. Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use; nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by impli­cation or otherwise under the patent rights of Analog Devices, Inc.
Trademark and Service Mark Notice
The Analog Devices logo, the CROSSCORE logo, VisualDSP++, Blackfin, SHARC, TigerSHARC, and EZ-KIT Lite are registered trademarks of Analog Devices, Inc.
All other brand and product names are trademarks or service marks of their respective owners.

CONTENTS

PREFACE
Purpose of This Manual ................................................................. vii
Intended Audience ......................................................................... vii
Manual Contents .......................................................................... viii
What’s New in This Manual .......................................................... viii
Technical or Customer Support ....................................................... ix
Supported Processors ........................................................................ x
Product Information ....................................................................... xi
MyAnalog.com .......................................................................... xi
Processor Product Information ................................................... xi
Related Documents .................................................................. xii
Online Technical Documentation ............................................ xiii
Accessing Documentation From VisualDSP++ ...................... xiv
Accessing Documentation From Windows ............................ xiv
Accessing Documentation From the Web ............................... xv
Printed Manuals ........................................................................ xv
VisualAudio or VisualDSP++ Documentation Set .................. xv
Hardware Tools Manuals ....................................................... xv
Processor Manuals ................................................................. xv
VisualDSP++ 4.0 Getting Started Guide iii
Data Sheets ......................................................................... xvi
Contacting DSP Publications ................................................... xvi
Notation Conventions ................................................................... xvi
FEATURES AND TOOLS
VisualDSP++ Features .................................................................. 1-1
New Features in Release 4.0 .......................................................... 1-5
Code Development Tools .............................................................. 1-7
BASIC TUTORIAL
Overview ...................................................................................... 2-1
Exercise One: Building and Running a C Program ......................... 2-3
Step 1: Start VisualDSP++ and Open a Project ......................... 2-4
Step 2: Build the dotprodc Project ........................................... 2-7
Step 3: Run the Program ....................................................... 2-10
Step 4: Run dotprodc ............................................................ 2-15
Exercise Two: Modifying a C Program to Call
an Assembly Routine ............................................................... 2-16
Step 1: Create a New Project ................................................. 2-16
Step 2: Add Source Files to dot_product_asm ........................ 2-22
Step 3: Create a Linker Description File ................................. 2-23
Step 4: Modify the Project Source Files .................................. 2-28
Step 5: Use the Expert Linker to Modify dot_prod_asm.ldf .... 2-32
Step 6: Rebuild and Run dot_product_asm ............................ 2-35
iv VisualDSP++ 4.0 Getting Started Guide
Exercise Three: Plotting Data ...................................................... 2-37
Step 1: Load the FIR Program ................................................ 2-37
Step 2: Open a Plot Window ................................................. 2-39
Step 3: Run the FIR Program and View the Data ................... 2-42
Exercise Four: Linear Profiling ..................................................... 2-51
Step 1: Load the FIR Program ................................................ 2-51
Step 2: Open the Profiling Window ....................................... 2-52
Step 3: Collect and Examine the Linear Profile Data ............... 2-54
ADVANCED TUTORIAL
Overview ...................................................................................... 3-1
Exercise One: Using Profile-Guided Optimization ......................... 3-2
Step 1: Load the Project ........................................................... 3-4
Step 2: Configure a Data Set .................................................... 3-5
Step 3: Attach an Input Stream .............................................. 3-10
Step 4: Configure Additional Data Sets .................................. 3-15
Step 5: Create PGO Files and Optimize the Program .............. 3-17
Step 6: Compare Execution Times ......................................... 3-18
Exercise Two: Using Background Telemetry Channel ................... 3-22
Adding BTC to Your DSP Application ................................... 3-22
Running the BTC Assembly Demo ........................................ 3-24
Step 1: Load the BTC_AsmDemo Project .......................... 3-25
Step 2: Examine the BTC Commands ................................ 3-26
Step 3: Set Up the BTC Memory Window and View Data 3-29
VisualDSP++ 4.0 Getting Started Guide v
Running the BTC FFT Demo ............................................... 3-37
Step 1: Build the FFT Demo ............................................. 3-38
Step 2: Plot BTC Data ...................................................... 3-39
Step 3: Record and Analyze BTC Data .............................. 3-44
INDEX
vi VisualDSP++ 4.0 Getting Started Guide

PREFACE

Thank you for purchasing VisualDSP++™, the development software for Analog Devices processors.

Purpose of This Manual

The VisualDSP++ 4.0 Getting Started Guide provides basic and advanced tutorials that highlight many VisualDSP++ features. By completing the step-by-step procedures, you will become familiar with the VisualDSP++ environment and learn how to use these features in your own digital signal processing (DSP) development projects.

Intended Audience

This manual is intended for DSP programmers who are familiar with Analog Devices processors. The manual assumes that the audience has a working knowledge of Analog Devices processor architecture and instruc­tion set.
DSP programmers who are unfamiliar with Analog Devices processors should refer to their processor’s Hardware Reference and Instruction Set Reference, which describe the processor architecture and instruction set. Note that the ADSP-BF533 Blackfin Processor Hardware Reference includes information about the ADSP-BF531 and ADSP-BF532 processors.
VisualDSP++ 4.0 Getting Started Guide vii

Manual Contents

Manual Contents
This manual consists of:
Chapter 1, “Features and Tools”
Provides an overview of VisualDSP++ features and code development tools
Chapter 2, “Basic Tutorial”
Provides step-by-step instructions for creating sessions, and for building and debugging projects by using examples of C/C++ and assembly sources
The tutorial is organized to follow the steps that you take in developing a typical programming project. Before you begin actual programming, you should be familiar with the architecture of your particular processor and the other software development tools.
Chapter 3, “Advanced Tutorial”
Provides step-by-step instructions for using profile-guided optimization (PGO) and background telemetry channel (BTC)

What’s New in This Manual

This manual contains updated example screens and procedures for the 4.0 Integrated Development and Debugging Environment (IDDE).
viii VisualDSP++ 4.0 Getting Started Guide

Technical or Customer Support

You can reach Analog Devices, Inc. Customer Support in the following ways:
Visit the Embedded Processing and DSP products Web site at
http://www.analog.com/processors/technicalSupport
E-mail tools questions to
dsptools.support@analog.com
E-mail processor questions to
dsp.support@analog.com
Phone questions to 1-800-ANALOGD
Contact your Analog Devices, Inc. local sales office or authorized distributor
Preface
Send questions by mail to:
Analog Devices, Inc. One Technology Way P.O. Box 9106 Norwood, MA 02062-9106 USA
VisualDSP++ 4.0 Getting Started Guide ix

Supported Processors

Supported Processors
The name “Blackfin®” refers to a family of Analog Devices 16-bit, embedded processors. VisualDSP++ currently supports the following Blackfin processors.
ADSP-BF531 ADSP-BF532 (formerly ADSP-21532)
ADSP-BF533 ADSP-BF535 (formerly ADSP-21535)
ADSP-BF534 ADSP-BF536
ADSP-BF537 ADSP-BF538
ADSP-BF539 ADSP-BF566
ADSP-BF561 AD6532
The names “SHARC Devices 32-bit, digital signal processors. VisualDSP++ currently supports the following SHARC processors.
ADSP-21020 ADSP-21261
ADSP-21060 ADSP-21262
ADSP-21061 ADSP-21266
ADSP-21062 ADSP-21267
ADSP-21065L ADSP-21363
ADSP-21160 ADSP-21364
ADSP-21161 ADSP-21365
VisualDSP++ currently supports the following TigerSHARC processors.
ADSP-TS101 ADSP-TS202
ADSP-TS201 ADSP-TS203
®
” and “TigerSHARC®” refer to the family of Analog
x VisualDSP++ 4.0 Getting Started Guide

Product Information

You can obtain product information from the Analog Devices website, from the product CD-ROM, or from the printed publications (manuals).
Preface
Analog Devices is online at
www.analog.com. Our website provides infor-
mation about a broad range of products—analog integrated circuits, amplifiers, converters, and digital signal processors.

MyAnalog.com

MyAnalog.com is a free feature of the Analog Devices website that allows
customization of a webpage to display only the latest information on products you are interested in. You can also choose to receive weekly email notification containing updates to the webpages that meet your interests.
MyAnalog.com provides access to books, application notes, data sheets,
code examples, and more.
Registration:
Visit
www.myanalog.com to sign up. Click Register to use MyAnalog.com.
Registration takes about five minutes and serves as means for you to select the information you want to receive.
If you are already a registered user, just log on. Your user name is your email address.

Processor Product Information

For information on embedded processors and DSPs, visit our Web site at
www.analog.com/processors, which provides access to technical publica-
tions, data sheets, application notes, product overviews, and product announcements.
VisualDSP++ 4.0 Getting Started Guide xi
Product Information
You may also obtain additional information about Analog Devices and its products in any of the following ways.
E-mail questions or requests for information to
embedded.support@analog.com
Fax questions or requests for information to
1-781-461-3010 (North America) 089/76 903-557 (Europe)
Access the FTP Web site at
ftp ftp.analog.com or ftp 137.71.23.21 ftp://ftp.analog.com

Related Documents

For information on product related development software, see these publications:
VisualDSP++ 4.0 User’s Guide
VisualDSP++ 4.0 Assembler and Preprocessor Manual
VisualDSP++ 4.0 C/C++ Compiler and Library Manual for SHARC
Processors
VisualDSP++ 4.0 C/C++ Compiler and Library Manual for
TigerSHARC Processors
VisualDSP++ 4.0 C/C++ Compiler and Library Manual for Blackfin
Processors
VisualDSP++ 4.0 Linker and Utilities Manual
VisualDSP++ 4.0 Loader Manual
VisualDSP++ 4.0 Product Release Bulletin
xii VisualDSP++ 4.0 Getting Started Guide
Product Information
VisualDSP++ 4.0 Kernel (VDK) User’s Guide
VisualDSP++ 4.0 Quick Installation Reference Card
For hardware information, refer to your processors’s hardware reference, programming reference, or data sheet. All documentation is available online. Most documentation is available in printed form.
Visit the Technical Library Web site to access all processor and tools man­uals and data sheets:
http://www.analog.com/processors/resources/technicalLibrary

Online Technical Documentation

Online documentation includes the VisualDSP++ Help system, software tools manuals, hardware tools manuals, processor manuals, Dinkum Abridged C++ library, and Flexible License Manager (FlexLM) network license manager software documentation. You can easily search across the entire VisualDSP++ documentation set for any topic of interest using the Search function of VisualDSP++ Help system. For easy printing, supple­mentary
.PDF files of most manuals are also provided.
Each documentation file type is described as follows.
File Description
.CHM Help system files and manuals in Help format
.HTM or .HTML
.PDF VisualDSP++ and processor manuals in Portable Documentation Format (PDF).
Dinkum Abridged C++ library and FlexLM network license manager software doc­umentation. Viewing and printing the Internet Explorer 4.0 (or higher).
Viewing and printing the Reader (4.0 or higher).
.PDF files requires a PDF reader, such as Adobe Acrobat
.HTML files requires a browser, such as
Access the online documentation from the VisualDSP++ environment, Windows
®
Explorer, or the Analog Devices Web site.
xiv VisualDSP++ 4.0 Product Release Bulletin
Product Information
If documentation is not installed on your system as part of the software installation, you can add it from the VisualDSP++ CD-ROM at any time by running the VisualDSP++ installation. Access the online documenta­tion from the VisualDSP++ environment, Windows
®
Explorer, or the
Analog Devices Web site.
Accessing Documentation From VisualDSP++
From the VisualDSP++ environment:
Access VisualDSP++ online Help from the Help menu’s Contents, Search, and Index commands.
Open online Help from context-sensitive user interface items (toolbar buttons, menu commands, and windows).
Accessing Documentation From Windows
In addition to any shortcuts you may have constructed, there are other ways to open VisualDSP++ online Help or the supplementary documenta­tion from Windows.
Help system files (. located in the
CHM) are located in the Help folder, and .PDF files are
Docs folder of your VisualDSP++ installation CD-ROM.
Using Windows Explorer
Double-click the
vdsp-help.chm file, which is the master Help
system, to access all the other .CHM files.
Double-click any file that is part of the VisualDSP++ documenta­tion set.
xiv VisualDSP++ 4.0 Getting Started Guide
Preface
Accessing Documentation From the Web
Download manuals at the following Web site:
http://www.analog.com/processors/resources/technicalLibrary/manuals
Select a processor family and book title. Download archive (.ZIP) files, one for each manual. Use any archive management software, such as WinZip, to decompress downloaded files.

Printed Manuals

For general questions regarding literature ordering, call the Literature Center at 1-800-ANALOGD (1-800-262-5643) and follow the prompts.
VisualAudio or VisualDSP++ Documentation Set
To purchase VisualDSP++ manuals, call 1-603-883-2430. The manuals may be purchased only as a kit.
If you do not have an account with Analog Devices, you are referred to Analog Devices distributors. For information on our distributors, log onto
http://www.analog.com/salesdir/continent.asp.
Hardware Tools Manuals
®
To purchase EZ-KIT Lite
and In-Circuit Emulator (ICE) manuals, call 1-603-883-2430. The manuals may be ordered by title or by product number located on the back cover of each manual.
Processor Manuals
Hardware reference and instruction set reference manuals may be ordered through the Literature Center at 1-800-ANALOGD (1-800-262-5643), or downloaded from the Analog Devices Web site. Manuals may be ordered by title or by product number located on the back cover of each manual.
VisualDSP++ 4.0 Getting Started Guide xv

Notation Conventions

Data Sheets
All data sheets (preliminary and production) may be downloaded from the Analog Devices Web site. Only production (final) data sheets (Rev. 0, A, B, C, and so on) can be obtained from the Literature Center at 1-800-ANALOGD (1-800-262-5643); they also can be downloaded from the Web site.
To have a data sheet faxed to you, call the Analog Devices Faxback System at 1-800-446-6212. Follow the prompts and a list of data sheet code numbers will be faxed to you. If the data sheet you want is not listed, check for it on the Web site.

Contacting DSP Publications

Please send your comments and recommendations for improving our manuals and online Help. You can contact us by sending an email to
dsp.techpubs@analog.com:
Notation Conventions
Text conventions used in this manual are identified and described as follows.
Example Description
Close command (File menu)
{this | that} Alternative required items in syntax descriptions appear within curly
[this | that] Optional items in syntax descriptions appear within brackets and
xvi VisualDSP++ 4.0 Getting Started Guide
Titles in reference sections indicate the location of an item within the VisualAudio environment’s menu system (for example, the Close command appears on the File menu).
brackets and separated by vertical bars; read the example as
that. One or the other is required.
separated by vertical bars; read the example as an optional this or
.
that
this or
Preface
Example Description
[this,…] Optional item lists in syntax descriptions appear within brackets
delimited by commas and terminated with an ellipse; read the example as an optional comma-separated list of
.SECTION Commands, directives, keywords, and feature names are in text with
letter gothic font.
filename Non-keyword placeholders appear in text with italic style format.
Note: For correct operation, ... A Note provides supplementary information on a related topic. In the
L
a
[
online version of this book, the word Note appears instead of this symbol.
Caution: Incorrect device operation may result if ... Caution: Device damage may result if ...
A Caution identifies conditions or inappropriate usage of the product that could lead to undesirable results or product damage. In the online version of this book, the word Caution appears instead of this symbol.
Warn in g: Injury to device users may result if ... A Warning identifies conditions or inappropriate usage of the product that could lead to conditions that are potentially hazardous for devices users. In the online version of this book, the word Wa rnin g appears instead of this symbol.
this.
L
VisualDSP++ 4.0 Getting Started Guide xvii
Additional conventions, which apply only to specific chapters, may appear throughout this document.
Notation Conventions
xviii VisualDSP++ 4.0 Getting Started Guide

1 FEATURES AND TOOLS

This chapter contains the following topics.
“VisualDSP++ Features” on page 1-1
“New Features in Release 4.0” on page 1-5
“Code Development Tools” on page 1-6

VisualDSP++ Features

VisualDSP++ provides these features:
Extensive editing capabilities. Create and modify source files by using multiple language syntax highlighting, drag-and-drop, book­marks, and other standard editing operations. View files generated by the code development tools.
Flexible project management. Specify a project definition that identifies the files, dependencies, and tools that you use to build projects. Create this project definition once or modify it to meet changing development needs.
VisualDSP++ 4.0 Getting Started Guide 1-1
VisualDSP++ Features
Easy access to code development tools. Analog Devices provides these code development tools: C/C++ compiler, assembler, linker, splitter, and loader. Specify options for these tools by using dialog boxes instead of complicated command-line scripts. Options that control how the tools process inputs and generate outputs have a one-to-one correspondence to command-line switches. Define options for a single file or for an entire project. Define these options once or modify them as necessary.
Flexible project build options. Control builds at the file or project level. VisualDSP++ enables you to build files or projects selectively, update project dependencies, or incrementally build only the files that have changed since the previous build. View the status of your project build in progress. If the build reports an error, double-click on the file name in the error message to open that source file. Then correct the error, rebuild the file or project, and start a debug session.
VisualDSP++ Kernel (VDK) support. Add VDK support to a project to structure and scale application development. The Kernel page of the Project window enables you to manipulate events, event bits, priorities, semaphores, and thread types.
Flexible workspace management. Create up to ten workspaces and quickly switch between them. Assigning a different project to each workspace enables you to build and debug multiple projects in a single session.
Easy movement between debug and build activities. Start the debug session and move freely between editing, build, and debug activities.
1-2 VisualDSP++ 4.0 Getting Started Guide
Features and Tools
Figure 1-1 shows the Integrated Development and Debugging
Environment (IDDE).

Figure 1-1. The VisualDSP++ IDDE

VisualDSP++ 4.0 Getting Started Guide 1-3
VisualDSP++ Features
VisualDSP++ reduces debugging time by providing these key features:
Easy-to-use debugging activities. Debug with one common, easy-to-use interface for all processor simulators and emulators, or hardware evaluation and development boards. Switch easily between these targets.
Multiple language support. Debug programs written in C, C++, or assembly, and view your program in machine code. For programs written in C/C++, you can view the source in C/C++ or mixed C/C++ and assembly, and display the values of local variables or evaluate expressions (global and local) based on the current context.
Effective debug control. Set breakpoints on symbols and addresses and then step through the program’s execution to find problems in coding logic. Set watchpoints (conditional breakpoints) on registers, stacks, and memory locations to identify when they are accessed.
Tools for improving performance. Use the trace, profile, and linear and statistical profiles to identify bottlenecks in your DSP application and to identify program optimization needs. Use plotting to view data arrays graphically. Generate interrupts, outputs, and inputs to simulate real-world application conditions.
1-4 VisualDSP++ 4.0 Getting Started Guide

New Features in Release 4.0

Release 4.0 includes these new features and enhancements:
Support for new processors. VisualDSP++ supports these new Blackfin processors: ADSP-BF534, ADSP-BF536, ADSP-BF537, ADSP-BF538 ADSP-BF539, ADSP-BF566
New Project Wizard. This feature lets you create and configure a DSP project with code that sets up peripherals like cache, DMA ports, I/O ports, and so on. An LDF can be added to the project to link in only necessary libraries, and plug-ins can be added to ana­lyze system performance and determine optimal parameters for the peripherals. Selecting New and then Project from the File menu now launches a New Project Wizard where you specify project options such as Name, Directory, Project type (standard applica­tion or multithreaded application using VDK), Processor, Silicon revision, Output type (executable file or Loader file).
Features and Tools
Build engine enhancements. You can select multiple files in the Project window and issue a Build Files command to build multiple
files simultaneously. You can use a Batch Build command to open a dialog box that lets you manage batch builds for multiple build targets. In the Output window, you now have the option of displaying only file names instead of command lines while building a project. A new Project Group file lets you store project group information in a file to allow the quick restoring and convenient sharing of information. The Project menu includes new project group options (Open Project Group, Save Project Group, Save Project Group As, and Close Project Group).
VisualDSP++ 4.0 Getting Started Guide 1-5
New Features in Release 4.0
Changes to Image Viewer. In addition to Grayscale 8 and RGB24, these pixel formats are now supported: Grayscale 12, Grayscale 16, RGB555, RGB565, and RGB32. These YUV pixel formats are also supported: YUV2 (4:2:2), YVYU (4:2:2), UYVY (4:2:2), and IYU2 (4:4:4). Display and processing speed has been improved through the use of the graphics device interface (GDI+). Image Viewer can now convert color formats from YUV to RGB and visa-versa, and transfer JPEG binary data to and from DSP memory. New functions have been added for advanced image processing (rotating and flipping images, filtering, auto-refreshing). New controls have been added to the Image Configuration dialog box, a toolbar has been added to the Image Viewer window.
New Project Options dialog box. A tree navigation control on the left side of the dialog box has replaced tabs for selecting the page view (General, Compiler, Assemble, Link, Load, Pre-build, or Post-build). Other changes include new fields and pages for configuring project options.
Changes to licensing management. Three types of licenses are available: TST (evaluation), KIT (evaluation), and ADI (permanent).
A TST (test drive) license provides unlimited (unrestricted) access to VisualDSP++ for emulation and simulation. You must register the software to receive a TST serial number, which expires 90 days after installation. After the 90 days, the software is inoperable.
A KIT license provides 10 days to register and validate the installa­tion. Once validated, the KIT licence extends to 90 (ninety) days of a full evaluation in total. At the end of the evaluation period,
unless you have added a permanent license, simulator and emulator connections become prohibited and the size of the user program is
limited.
1-6 VisualDSP++ 4.0 Getting Started Guide
An ADI license provides 30 (thirty) days to register and validate the installation for a permanent use. If you fail to register and vali­date your installation during the 30-day evaluation period, your copy of VisualDSP++ 4.0 becomes inoperable.
Code Development Tools
Code development tools include:
C/C++ compiler
Run-time library with over 100 math, DSP, and C run-time library routines
•Assembler
•Linker
Features and Tools
Splitter
•Loader
Simulator
Emulator (must be purchased separately from VisualDSP++)
These tools enable you to develop applications that take full advantage of your processor’s architecture.
The VisualDSP++ linker supports multiprocessing, shared memory, and memory overlays.
VisualDSP++ 4.0 Getting Started Guide 1-7
Code Development Tools
The code development tools provide these key features:
Easy-to-program C, C++, and assembly languages. Program in C/C++, assembly, or a mix of C/C++ and assembly in one source. The assembly language is based on an algebraic syntax that is easy to learn, program, and debug.
Flexible system definition. Define multiple types of executables for a single type of processor in one Linker Description File ( Specify input files, including objects, libraries, shared memory files, overlay files, and executables.
Support for overlays, multiprocessors, and shared memory executables. The linker places code and resolves symbols in multi­processor memory space for use by multiprocessor systems. The loader enables you to configure multiple processors with less code and faster boot time. Create host, link port, and PROM boot images.
.LDF).
Software and hardware tool kits include context-sensitive Help and manuals in PDF format.
For details about assembly syntax, refer to the VisualDSP++ 4.0 Assembler and Preprocessor Manual for your target processor.
1-8 VisualDSP++ 4.0 Getting Started Guide

2 BASIC TUTORIAL

This chapter contains the following topics.
“Overview” on page 2-1
“Exercise One: Building and Running a C Program” on page 2-3
“Exercise Two: Modifying a C Program to Call an Assembly Rou-
tine” on page 2-16
“Exercise Three: Plotting Data” on page 2-37
“Exercise Four: Linear Profiling” on page 2-51

Overview

The Basic Tutorial demonstrates key features and capabilities of the VisualDSP++ Integrated Development and Debugging Environment (IDDE). The exercises use sample programs written in C and assembly for Blackfin processors.
You can use different Blackfin processors with only minor changes to the Linker Description Files (.LDFs) included with each project. VisualDSP++ includes basic Linker Description Files for each processor type in the folder. For Blackfin processors, the folder’s default installation path is:
Program Files\Analog Devices\VisualDSP 4.0\Blackfin\ldf
The source files for these exercises are installed during the VisualDSP++ software installation.
VisualDSP++ 4.0 Getting Started Guide 2-1
ldf
Overview
The tutorial contains four exercises:
•In Exercise One, you start up VisualDSP++, build a project containing C source code, and profile the performance of a C function.
•In Exercise Two, you create a new project, create a Linker Description File to link with the assembly routine, rebuild the project, and profile the performance of the assembly language routine.
•In Exercise Three, you plot the various waveforms produced by a Finite Impulse Response (FIR) algorithm.
•In Exercise Four, you use linear profiling to examine the efficiency of the FIR algorithm used in Exercise Three. Using the collected linear profile data, you pinpoint the most time-consuming areas of the algorithm, which are likely to require hand tuning in the assembly language.
The ADSP-BF53x Family Simulator and ADSP-BF533 processor are used for all exercises.
Tip: Become familiar with the VisualDSP++ toolbar buttons, shown in
Figure 2-1. They are shortcuts for menu commands such as Open a file
and Run a program. Toolbar buttons and menu commands that are not available for tasks are disabled and displayed in gray.

Figure 2-1. VisualDSP++ Toolbar Buttons

2-2 VisualDSP++ 4.0 Getting Started Guide
Basic Tutorial
L
VisualDSP++ is a licensed software product. To run the software, you must have a valid license installed on your system. If you try to run VisualDSP++ and a license is not installed, a message window opens to let you add a license. For details about license manage­ment, see the VisualDSP++ 4.0 User’s Guide or VisualDSP++ online Help.

Exercise One: Building and Running a C Program

In this exercise, you:
Start up the VisualDSP++ environment
Open and build an existing project
Examine windows and dialog boxes
Run the program
The sources for this exercise are in the dot_product_c folder. The default installation path is:
Program Files\Analog Devices\VisualDSP 4.0\Blackfin\Examples\ Tutorial\dot_product_c
VisualDSP++ 4.0 Getting Started Guide 2-3
Exercise One: Building and Running a C Program

Step 1: Start VisualDSP++ and Open a Project

To start VisualDSP++ and open a project:
1. Click the Windows Start button and select Programs, Analog Devices, VisualDSP++ 4.0, and VisualDSP++ Environment.
If you are running VisualDSP++ for the first time, the New Session dialog box (Figure 2-6 on page 2-11) opens to enable you to set up a session.
a. Select the values shown in Table 2-1.
Table 2-1. Session Specification
Box Value
Debug Target ADSP-BF5xx Blackfin Family Simulator
Platform ADSP-BF5xx Single Processor Simulator
Session Name ADSP-BF533 Simulator
Processor ADSP-BF533
b. Click OK. The VisualDSP++ main window appears.
If you have already run VisualDSP++ and the Reload last project at
startup option is selected on the Project page under Settings and Preferences, VisualDSP++ opens the last project that you worked
on. To close this project, choose Close from the Project menu, and then click No when prompted to save the project. Since you have made no changes to the project, you do not have to save it.
2. From the File menu, choose Open and then Project.
VisualDSP++ displays the Open Project dialog box.
2-4 VisualDSP++ 4.0 Getting Started Guide
Basic Tutorial
3. In the Look in box, open the folder and double-click the following subfolders in succession.
VisualDSP 4.0\Blackfin\Examples\Tutorial\dot_product_c
This path is based on the default installation.
Program Files\Analog Devices
L
4. Double-click the dotprodc project (.dpj) file.
VisualDSP++ loads the project in the Project window, as shown in
Figure 2-2. The environment displays messages in the Output
window as it processes the project settings and file dependencies.
Figure 2-2. Project Loaded in the Project Window
dotprodc project comprises two C language source files,
The
dotprod.c and dotprod_main.c, which define the arrays and
calculate their dot products.
VisualDSP++ 4.0 Getting Started Guide 2-5
Exercise One: Building and Running a C Program
5. From the Settings menu, choose Preferences to open the Preferences dialog box, shown in Figure 2-3.
Figure 2-3. Preferences Dialog Box
6. On the General page, under General Preferences, ensure that the following options are selected.
Run to main after load
Load executable after build
7. Click OK to close the Preferences dialog box.
The VisualDSP++ main window appears. You are now ready to build the project.
2-6 VisualDSP++ 4.0 Getting Started Guide

Step 2: Build the dotprodc Project

To build the dotprodc project:
1. From the Project menu, choose Build Project.
VisualDSP++ first checks and updates the project dependencies and then builds the project by using the project source files.
As the build progresses, the Output window displays status messages (error and informational) from the tools. For example, when a tool detects invalid syntax or a missing reference, the tool reports the error in the Output window.
If you double-click the file name in the error message, VisualDSP++ opens the source file in an editor window. You can then edit the source to correct the error, rebuild, and launch the debug session. If the project build is up-to-date (the files, dependencies, and options have not changed since the last project build), no build is performed unless you run the Rebuild All command. Instead, you see the message “Project is up to date.” If the build has no errors, a message reports “Build completed
successfully.”
Basic Tutorial
VisualDSP++ 4.0 Getting Started Guide 2-7
Exercise One: Building and Running a C Program
In this example (Figure 2-4) notice that the compiler detects an undefined identifier and issues the following error in the Build view of the Output window.
Figure 2-4. Example of Error Message
2. Double-click the error message text in the Output window.
VisualDSP++ opens the C source file
dotprod_main.c in an editor
window and places the cursor on the line that contains the error (see Figure 2-5).
The editor window in Figure 2-5 shows that the integer variable declaration int has been misspelled as itn.
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Figure 2-5. Output Window and Editor Window
3. In the editor window, click on itn and change it to int. Notice that int is now color coded to signify that it is a valid C keyword.
4. Save the source file by choosing File dotprod_main.c from the FileSave menu.
5. Build the project again by choosing Build Project from the Project menu. The project is now built without any errors, as reported in the Build view of the Output window.
VisualDSP++ 4.0 Getting Started Guide 2-9
Exercise One: Building and Running a C Program
Now that you have built your project successfully, you can run the example program.

Step 3: Run the Program

In this procedure, you:
Set up the debug session before running the program
View debugger windows and dialog boxes
Since you enabled Load executable after build on the General page in the Preferences dialog box, the executable file dotprodc.dxe is automatically downloaded to the target. If the debug session’s processor does not match the project’s build target, VisualDSP++ reports this discrepancy and asks if you want to select another session before downloading the executable to the target. If VisualDSP++ does not open the Session List dialog box, skip steps 1–4.
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To set up the debug session:
1. In the Session List dialog box, click New Session to open the New Session dialog box, shown in Figure 2-6.
For subsequent debugging sessions, use the New Session command on the Sessions menu to open the New Session dialog box.
Figure 2-6. New Session Dialog Box
2. Specify the target and processor information listed in Table 2-2.
Table 2-2. Session Specification
Box Value
Debug Target ADSP-BF5xx Blackfin Family Simulator
Platform ADSP-BF5xx Single Processor Simulator
Session Name ADSP-BF533 Simulator
Processor ADSP-BF533
VisualDSP++ 4.0 Getting Started Guide 2-11
Exercise One: Building and Running a C Program
3. Click OK to close the New Session dialog box and return to the Session List dialog box.
4. With the new session name highlighted, click Activate.
L
If you do not click Activate, the session mismatch message appears again.
VisualDSP++ closes the Session List dialog box, automatically loads your project’s executable file (dotprodc.dxe), and advances to the main function of your code (see Figure 2-7).
Figure 2-7. Loading dotprodc.dxe
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5. Look at the information in the open windows.
The Output window’s Console page contains messages about the status of the debug session. In this case, VisualDSP++ reports that the
dotprodc.dxe load is complete.
The Disassembly window displays the assembly code for the executable. Use the scroll bars to move around the Disassembly window.
Note that a solid red circle and a yellow arrow appear at the start of the program labeled “main”. The solid red circle ( ) indicates that a breakpoint is set on that instruction, and the yellow arrow ( ) indicates that the processor is currently halted at that instruction. When VisualDSP++ loads your C program, it automatically sets two breakpoints, one at the beginning and one at the end of code execution. Your breakpoint locations may differ slightly from those shown in the examples in this book.
6. From the Settings menu, choose Breakpoints to view the break­points set in your program. VisualDSP++ displays the Breakpoints dialog box, shown in Figure 2-8.
VisualDSP++ 4.0 Getting Started Guide 2-13
Exercise One: Building and Running a C Program
Figure 2-8. Breakpoints Dialog Box
The breakpoints are set at these C program locations:
at main + 0x04
at __lib_prog_term
The Breakpoints dialog box enables you to view, add, and delete breakpoints and to browse for symbols. In the Disassembly and editor windows, double-clicking on a line of code toggles (adds or deletes) breakpoints. In the editor window, however, you must place the mouse pointer in the gutter before double-clicking.
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These tool buttons set or clear breakpoints:
Toggles a breakpoint for the current line
Clears all breakpoints
7. Click OK or Cancel to exit the Breakpoints dialog box.

Step 4: Run dotprodc

To run dotprodc, click the Run button or choose Run from the Debug menu.
VisualDSP++ computes the dot products and displays the following results on the Console view (Figure 2-9) of the Output window.
Dot product [0] = 13273595 Dot product [1] = –49956078 Dot product [2] = 35872518
Figure 2-9. Results of the dotprodc Program
You are now ready to begin Exercise Two.
VisualDSP++ 4.0 Getting Started Guide 2-15

Exercise Two: Modifying a C Program to Call an Assembly Routine

Exercise Two: Modifying a C Program to Call an Assembly Routine
In Exercise One, you built and ran a C program. In this exercise, you:
Modify the C program to call an assembly language routine
Create a Linker Description File to link with the assembly routine
Rebuild the project
The project files are largely identical to those of Exercise One. Minor modifications illustrate the changes needed to call an assembly language routine from C source code.

Step 1: Create a New Project

To create a new project:
1. From the File menu, choose Close and then Project dotprodc to close the dotprodc project.
Click Yes when prompted to close all open source windows.
If you have modified your project during this session, you are prompted to save the project. Click No.
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2. From the File menu, choose New and then Project to open the Project Wizard, shown in Figure 2-10.
Figure 2-10. Project Wizard – General Page
3. Click the browse button to the right of the Directory field to open the Browse For Folder dialog box. Locate the dot_product_asm tutorial folder and click OK. By default this directory is in the follow­ing location.
Program Files\Analog Devices\VisualDSP 4.0\Blackfin\ Examples\Tutorial\dot_product_asm
VisualDSP++ 4.0 Getting Started Guide 2-17
Exercise Two: Modifying a C Program to Call an Assembly Routine
4. In the Name field, type
dot_product_asm and click Finish. The new
project is created and is shown in the Project window of the IDDE.
5. From the Project menu click the Project Options command to display the Project Options dialog box (Figure 2-11).
Figure 2-11. Project Options Dialog Box – Project Page
This dialog box enables you to specify project build information.
6. Take a moment to view the various pages in the Project Options dialog box by selecting them from the tree on the left: Project,
General, Compile, Assemble, Link, Load, Pre-Build, and Post-Build. On each page, you specify the tool options used to
build the project.
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7. On the Project page (Figure 2-11), verify that the values shown in
Table 2-3 are entered here.
Table 2-3. Completing the Project Page
Field Value
Processor ADSP-BF533
Revision Automatic
Type Executable file
Name dot_product_asm
Settings for configuration Debug
These settings specify information for building an executable file for the ADSP-BF533 processor. The executable contains debug information, so you can examine program execution.
8. Click the Compile tab to display the Compile page, shown in
Figure 2-12.
VisualDSP++ 4.0 Getting Started Guide 2-19
Exercise Two: Modifying a C Program to Call an Assembly Routine
Figure 2-12. Project Options Dialog Box – Compile Page
9. Specify these settings in the Code Generation group box:
a. Select the Enable optimization check box to enable
optimization.
b. Select the Generate debug information check box, if it is
not already selected, to enable debug information for the C source.
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These settings direct the C compiler to optimize code for the ADSP-BF533 processor. Because the optimization takes advantage of DSP architecture and assembly language features, some of the C debug information is not saved. Therefore, debugging is performed through debug information at the assembly language level.
10. Click OK to apply changes to the project options and to close the Project Options dialog box. When prompted to add support for the VisualDSP++ kernel, click No.
You are now ready to add the source files to the project.
VisualDSP++ 4.0 Getting Started Guide 2-21
Exercise Two: Modifying a C Program to Call an Assembly Routine

Step 2: Add Source Files to dot_product_asm

To add the source files to the new project:
1. Click the Add File button , or from the Project menu, choose Add to Project, and then choose File(s).
The Add Files dialog box (Figure 2-13) appears.
Figure 2-13. Add Files Dialog Box – Adding Source Files to the Project
2. In the Look in box, locate the project folder,
dot_product_asm.
3. In the Files of type box, select All Source Files from the drop-down list.
4. Hold down the Ctrl key and click dotprod.c and dotprod_main.c. Then click Add.
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To display the files that you added in step 4, open the
Files folder in the Project window.
You are now ready to create a Linker Description File for the project.

Step 3: Create a Linker Description File

In this procedure, you use the Expert Linker to create a Linker Description File for the project.
To create a Linker Description File:
1. From the Tools menu, choose Expert Linker and then choose Create LDF to open the Create LDF Wizard, shown in
Figure 2-14.
Source
VisualDSP++ 4.0 Getting Started Guide 2-23
Exercise Two: Modifying a C Program to Call an Assembly Routine
Figure 2-14. Create LDF Wizard
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2. Click Next to display the Create LDF – Step 1 of 3 page, shown in
Figure 2-15.
Figure 2-15. Create LDF – Step 1 of 3 Page
This page enables you to assign the LDF file name (based on the project name) and to select the Project type.
VisualDSP++ 4.0 Getting Started Guide 2-25
Exercise Two: Modifying a C Program to Call an Assembly Routine
3. Accept the values selected for your project and click Next to display the Create LDF – Step 2 of 3 page, shown in Figure 2-16.
Figure 2-16. Create LDF – Step 2 of 3 Page
This page enables you to set the System type (defaulted to Single processor), the Processor type (defaulted to ADSP-BF533 to match the project), and the name of the linker Output file (defaulted to the name selected by the project).
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4. Accept the default values and click Next to display the Create LDF – Step 3 of 3 page, shown in Figure 2-17.
Figure 2-17. Create LDF – Step 3 of 3 Page
VisualDSP++ 4.0 Getting Started Guide 2-27
Exercise Two: Modifying a C Program to Call an Assembly Routine
5. Review the Summary of choices and click Finish to create the file.
You now have a new .LDF file in your project. The new file is in the Linker Files folder in the Project window.
The Expert Linker window opens with a representation of the new
.LDF file. This file is complete for this project. Close the Expert
Linker window.
6. Click the Rebuild All button to build the project. The C source file opens in an editor window, and execution halts.
The C version of the project is now complete. You are now ready to modify the sources to call the assembly function.

Step 4: Modify the Project Source Files

In this procedure, you:
•Modify dotprod_main.c to call a_dot_c_asm instead of a_dot_c
Save the modified file
.LDF
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To modify
dotprod_main.c to call the assembly function:
1. Resize or maximize the editor window for better viewing.
2. From the Edit menu, choose Find to open the Find dialog box, shown in Figure 2-18.
Figure 2-18. Find Dialog Box: Locating Occurrences of /*
3. In the Find What box, type /*, and then click Mark All.
The editor bookmarks all lines containing /* and positions the cursor at the first instance of /* in the extern int a_dot_c_asm declaration.
VisualDSP++ 4.0 Getting Started Guide 2-29
Exercise Two: Modifying a C Program to Call an Assembly Routine
4. Select the comment characters
/* and use the Ctrl+X key combina-
tion to cut the comment characters from the beginning of the
a_dot_c_asm declaration. Then move the cursor up one line and
use the Ctrl+V key combination to paste the comment characters at the beginning of the a_dot_c declaration. Because syntax coloring is turned on, the code changes color as you cut and paste the comment characters.
Repeat this step for the end-of-comment characters */ at the end of the a_dot_c_asm declaration. The a_dot_c declaration is now fully commented out, and the a_dot_c_asm declaration is no longer commented.
5. Press F2 to move to the next bookmark.
The editor positions the cursor on the /* in the function call to
a_dot_c_asm, which is currently commented out. Note that the
previous line is the function call to the a_dot_c routine.
6. Press Ctrl+X to cut the comment characters from the beginning of the function call to a_dot_c_asm. Then move the cursor up one line and press Ctrl+V to paste the comment characters at the begin­ning of the call to a_dot_c.
Repeat this step for the end-of-comment characters */. The main() function is now calling the a_dot_c_asm routine instead of the
a_dot_c function (previously called in Exercise One).
Figure 2-19 shows the changes made in step 6.
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Figure 2-19. Modifying dotprod_main.c to Call a_dot_c_asm
7. From the File menu, choose Save and then File dotprod_main.c to save the changes to the file.
8. Place the cursor in the editor window. Then, from the File menu, choose Close and then File dotprod_main.c to close the
dotprod_main.c file.
You are now ready to modify
dotprodasm.ldf.
VisualDSP++ 4.0 Getting Started Guide 2-31
Exercise Two: Modifying a C Program to Call an Assembly Routine

Step 5: Use the Expert Linker to Modify dot_prod_asm.ldf

In this procedure you:
View the Expert Linker representation of the
.LDF file that you
created
Modify the
.LDF file to map in the section for the a_dot_c_asm
assembly routine
To examine and then modify dot_prod_asm.ldf to link with the assembly function:
1. Click the Add File button .
2. Select dotprod_func.asm and click Add.
3. Build the project by performing one of these actions:
Click the Build Project button .
From the Project menu, choose Build Project.
4. Notice the linker error in the Output window (Figure 2-20).
Figure 2-20. Output Window: Linker Error
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5. In the Project window, double-click in the
dot_prod_asm.ldf file.
The Expert Linker window (Figure 2-21) opens with a graphical representation of your file.
Resize the window to expand the view and change the view mode. To display the tree view shown in Figure 2-21, right-click in the right pane, choose View Mode, and then choose Memory Map Tree.
Figure 2-21. Expert Linker Window
The left pane (Input Sections) contains a list of the input sections that are in your project or are mapped in the
.LDF file. A red X is
over the icon in front of the section named “my_asm_section” because Expert Linker has determined that the section is not mapped by the .LDF file.
The right pane (Memory Map) contains a representation of the memory segments that Expert Linker defined when it created the
.LDF file.
VisualDSP++ 4.0 Getting Started Guide 2-33
Exercise Two: Modifying a C Program to Call an Assembly Routine
6. Map
my_asm_section into the memory segment named MEM_PROGRAM
as follows.
In the Input Sections pane, open my_asm_section by clicking on the plus sign in front of it. The input section expands to show that the linker macros $COMMAND_LINE_OBJECTS and $OBJECTS and the object file dotprod_func.doj have a section that has not been mapped. In the Memory Map pane, expand MEM_L1_CODE and drag the icon in front of $OBJECTS onto the program_ram output section under MEM_L1_CODE.
As shown in Figure 2-22, the red X should no longer appear because the section my_asm_section has been mapped.
Figure 2-22. Dragging $OBJECTS onto Program Output Section
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7. From the Tools menu, choose Expert Linker and Save to save the modified file. Then close the Expert Linker window.
If you forget to save the file and then rebuild the project, VisualDSP++ will see that you modified the file and will automatically save it.
You are now ready to rebuild and run the modified project.

Step 6: Rebuild and Run dot_product_asm

To run dot_product:
1. Build the project by performing one of these actions:
Click the Build Project button .
From the Project menu, choose Build Project.
At the end of the build, the Output window displays this message in the Build view:
Build completed successfully.
VisualDSP++ loads the program, runs to main, and displays the Output, Disassembly, and editor windows (shown in Figure 2-23).
VisualDSP++ 4.0 Getting Started Guide 2-35
Exercise Two: Modifying a C Program to Call an Assembly Routine
Figure 2-23. Windows Left Open from the Previous Debugger Session
2. Click the Run button to run
dot_product_asm.
The program calculates the three dot products and displays the results in the Console view of the Output window. When the program stops running, the message “
Halted” appears in the status
bar at the bottom of the VisualDSP++ main window. The results, shown below, are identical to the results obtained in Exercise One.
Dot product [0] = 13273595 Dot product [1] = –49956078 Dot product [2] = 35872518
You are now ready to begin Exercise Three.
2-36 VisualDSP++ 4.0 Getting Started Guide

Exercise Three: Plotting Data

In this exercise, you:
Load and debug a prebuilt program that applies a simple Finite Impulse Response (FIR) filter to a buffer of data
Use VisualDSP++’s plotting engine to view the different data arrays graphically, both before and after running the program

Step 1: Load the FIR Program

To load the FIR program:
1. Keep the Disassembly window and Console page (of the Output window) open, but close all other windows.
2. From the File menu, choose Load Program or click . The Open a Processor Program dialog box appears.
Basic Tutorial
3. Select the FIR program to load as follows.
a. Open the Analog Devices folder and double-click:
VisualDSP 4.0\Blackfin\Examples\Tutorial\fir
b. Double-click the Debug subfolder.
c. Double-click FIR.DXE to load the program.
If VisualDSP++ does not open an editor window (shown in
Figure 2-24), right-click in the Disassembly window and
select View Source.
VisualDSP++ 4.0 Getting Started Guide 2-37
Exercise Three: Plotting Data
Figure 2-24. Loading the FIR Program
4. Look at the source code of the FIR program.
You can see two global data arrays:
IN
OUT
You can also see one function, fir, that operates on these arrays.
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You are now ready to open a plot window.

Step 2: Open a Plot Window

To open a plot window:
1. From the View menu, choose Debug Windows and Plot. Then choose New to open the Plot Configuration dialog box, shown in
Figure 2-25.
Here you add the data sets that you want to view in a plot window.
Basic Tutorial
Figure 2-25. Plot Configuration Dialog Box
VisualDSP++ 4.0 Getting Started Guide 2-39
Exercise Three: Plotting Data
2. In the Plot group box, specify the following values.
•In the Type box, select Line Plot from the drop-down list.
•In the Title box, type
fir.
3. Enter two data sets to plot by using the values in Table 2-4.
Table 2-4. Two Data Sets: Input and Output
Box Input Data
Set
Name Input Output Data set
Memory BLACKFIN
Memory
Address IN OUT The address of this data set is that of the
Count 128 128 The array is 260 elements long, but you are
Stride 1 1 The data is contiguous in memory.
Data short short Input and Output are arrays of int values.
Output Data Set
BLACKFIN Memory
Description
Data memory
Input or Output array. Click Browse to select the value from the list of loaded symbols.
plotting the first 128 elements.
After entering each data set, click Add to add the data set to the Data sets list on the left of the dialog box.
The Plot Configuration dialog box should now look like the one in
Figure 2-26.
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Figure 2-26. Plot Configuration Dialog Box with Input/Output Data Sets
4. Click OK to apply the changes and to open a plot window with these data sets.
The plot window now displays the two arrays. By default, the simulator initializes memory to zero, so the Output data set appears as one horizontal line, shown in Figure 2-27.
VisualDSP++ 4.0 Getting Started Guide 2-41
Exercise Three: Plotting Data
Figure 2-27. Plot Window: Before Running the FIR Program
Resizing the plot window changes the scale on the x and y axis.
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5. Right-click in the plot window and choose Modify Settings. On the General page, in the Options group box, select Legend and click OK to display the legend box.

Step 3: Run the FIR Program and View the Data

To run the FIR program and view the data:
1. Press F5 or click the Run button to run to the end of the program.
When the program halts, you see the results of the FIR filter in the Output array. The two data sets are visible in the plot window, as shown in Figure 2-28.
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Figure 2-28. Plot Window After Running the FIR Program to Completion
Next you will zoom in on a particular region of interest in the plot window to focus in on the data.
VisualDSP++ 4.0 Getting Started Guide 2-43
Exercise Three: Plotting Data
2. Click the left mouse button inside the plot window and drag the mouse to create a rectangle around the area of interest. Then release the mouse button to magnify the selected region.
Figure 2-29 shows the selected region, and Figure 2-30 shows the
magnified result.
Figure 2-29. Plot Window: Selecting a Region to Magnify
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Figure 2-30. Plot Window: Magnified Result
To return to the previous view (before magnification), right-click in the plot window and choose Reset Zoom from the pop-up menu. You can view individual data points in the plot window by enabling the data cursor, as explained in the next step.
3. Right-click inside the plot window and choose Data Cursor from the pop-up menu. Move to each data point in the current data set by pressing and holding the Left () or Right () arrow key on the keyboard. To switch data sets, press the Up () or Down (↓) arrow key. The value of the current data point appears in the lower-left corner of the plot window, as shown in Figure 2-31.
VisualDSP++ 4.0 Getting Started Guide 2-45
Exercise Three: Plotting Data
Figure 2-31. Plot Window: Using the Data Cursor Feature
4. Right-click in the plot window and choose Data Cursor from the pop-up menu.
Next you will look at data sets in the frequency domain.
5. Right-click in the plot window and choose Modify Settings to open the Plot Settings dialog box.
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6. Complete these steps:
a. Click the Data Processing tab to display the Data Process-
ing page, shown in Figure 2-32.
Basic Tutorial
Figure 2-32. Data Processing Page
b. In the Data Sets box, ensure that Input (the default) is
selected. In the Data Process box, choose FFT Magnitude. c. In the Sample rate (Hz) box, type 10000. d. In the Data Sets box, select Output. In the Data Process
box, choose FFT Magnitude
VisualDSP++ 4.0 Getting Started Guide 2-47
Exercise Three: Plotting Data
e. Click OK to exit the Plot Settings dialog box.
VisualDSP++ performs a Fast Fourier Transform (FFT) on the selected data set before it is plotted. The FFT enables you to view the signal in the frequency domain, as shown in
Figure 2-33.
Figure 2-33. FFT Performed on a Selected Data Set
Now, complete the following steps to look at the FIR filter’s response in the frequency domain.
1. From the View menu, choose Debug Windows and Plot. Then choose New to open the Plot Configuration dialog box.
2. Set up the Filter Frequency Response plot by completing the Plot and Data Setting group boxes as shown in Figure 2-34.
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Figure 2-34. Filter Frequency Response Data Set
3. Click Add to add the data set to the Data sets box.
4. Click OK to apply the changes and to open the plot window with this data set.
5. Right-click in the plot window and choose Modify Settings to open the Plot Settings dialog box.
VisualDSP++ 4.0 Getting Started Guide 2-49
Exercise Three: Plotting Data
6. Click the Data Processing tab to display the Data Processing page, shown in Figure 2-32 on page 2-47. Complete this page as follows.
a. In the Data Sets box, select h.
b. In the Data Process box, choose FFT Magnitude.
c. In the Sample rate (Hz) box, type 10000.
d. Click OK to exit the Data Processing page.
VisualDSP++ performs a Fast Fourier Transform (FFT) on the selected data set, and enables you to view the filter response plot in the frequency domain, as shown in Figure 2-35.
Figure 2-35. Filter Frequency Response Plot
This plot shows that the low-pass FIR filter cuts off all frequency components above 4,000 Hz. When you apply a low-pass filter to the input signal, the resulting signal has no output above 4,000 Hz.
You are now ready to begin Exercise Four.
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Exercise Four: Linear Profiling

In this exercise, you:
Load and debug the FIR program from the previous exercise
Use linear profiling to evaluate the program’s efficiency and to determine where the application is spending the majority of its exe­cution time in the code
VisualDSP++ supports two types of profiling: linear and statistical.
You use linear profiling with a simulator. The count in the Linear Profiling Results window is incremented every time an assembly instruction is executed.
You use statistical profiling with a JTAG emulator connected to a processor target. The count in the Statistical Profiling Results window is based on random sampling of the program counter.
Basic Tutorial

Step 1: Load the FIR Program

To load the FIR program:
1. Close all open windows except the Disassembly window and the Output window.
2. From the File menu, choose Load Program, or click . The Open a Processor Program dialog box appears.
VisualDSP++ 4.0 Getting Started Guide 2-51
Exercise Four: Linear Profiling
3. Select the program to load as follows.
a. Open the
VisualDSP 4.0\Blackfin\Examples\Tutorial\fir
Analog Devices folder and double-click:
b. Double-click the Debug subfolder.
c. Double-click FIR.DXE to load and run the FIR program.
If VisualDSP++ does not open an editor window (shown in
Figure 2-37), right-click in the Disassembly window and
select View Source.
You are now ready to set up linear profiling.

Step 2: Open the Profiling Window

To open the Linear Profiling Results window:
1. From the Tools menu, choose Linear Profiling and then choose New Profile.
Figure 2-36. Setting Up Linear Profiling for the FIR Program
The Linear Profiling Results window opens without any data.
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2. Click in the profiling window’s title bar and then drag and drop the window to the top of the VisualDSP++ main window, as shown in Figure 2-37. You will have a better view of the profile data.
Figure 2-37. Linear Profiling Results Window (Empty)
The Linear Profiling Results window is initially empty. Linear profiling is performed when you run the FIR program. After you run the program and collect data, this window displays the results of the profiling session.
You are now ready to collect and examine linear profile data.
VisualDSP++ 4.0 Getting Started Guide 2-53
Exercise Four: Linear Profiling

Step 3: Collect and Examine the Linear Profile Data

To collect and examine the linear profile data:
1. Press F5 or click to run to the end of the program.
When the program halts, the results of the linear profile appear in the Linear Profiling Results window.
2. Examine the results of your linear profiling session.
The Linear Profiling Results window is divided into two three-column panes.
The left pane shows the results of the profile data. You can see the percentages of total execution time consumed, by function and by address.
Double-clicking a line with a function enables you to display the source file that contains that function. For example, double-click the fir function to display the assembly source file (fir.asm) in the right pane, as shown in Figure 2-38.
Figure 2-38. Linear Profiling Results, FIR Program Performance Analysis
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The field values in the left pane are defined as follows.
Histogram A graphical representation of the percentage of time
spent in a particular execution unit. This percentage is based on the total time that the program spent running, so longer bars denote more time spent in a particular execution unit. The Linear Profiling Results window always sorts the data with the most time-consuming (expensive) execution units at the top.
% The numerical percent of the same data found in
the Histogram column. You can view this value as an absolute number of samples by right-clicking in the Linear Profiling Results window and by select- ing View Sample Count from the pop-up menu.
Execution Unit The program location to which the samples belong.
If the instructions are inside a C function or a C++ method, the execution unit is the name of the func­tion or method. For instructions that have no corresponding symbolic names, such as hand-coded assembly or source files compiled without debug­ging information, this value is an address in the form of
PC[xxx], where xxx is the address of the
instruction.
If the instructions are part of an assembly file, the execution unit is either an assembly function or the assembly file followed by the line number in parentheses.
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Exercise Four: Linear Profiling
In Figure 2-38 on page 2-54 the left pane shows that the
fir function
consumes over 93% of the total execution time. The right (source) pane, shown in Figure 2-39, displays the percentage that each line in the fir function consumes.
Figure 2-39. Linear Profile Data for fir.asm
You have now completed the Basic Tutorial.
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3 ADVANCED TUTORIAL

This chapter contains the following topics.
“Overview” on page 3-1
“Exercise One: Using Profile-Guided Optimization” on page 3-2
“Exercise Two: Using Background Telemetry Channel” on
page 3-22

Overview

This tutorial demonstrates advanced features and techniques that you can use in the VisualDSP++ Integrated Development and Debugging Environ­ment (IDDE). The exercises use sample programs written in C and assembly for Blackfin processors.
•In Exercise One: Using Profile-Guided Optimization, you build a project with PGO support, create PGO files, compile the project without using the information in the PGO files, recompile the project by using the PGO files to optimize the build, check the PGO results, and compare execution times.
•In Exercise Two: Using Background Telemetry Channel, you add BTC to your DSP application and then run two demos that demonstrate BTC functionality.
The ADSP-BF53x Family Simulator and ADSP-BF533 processor are used in Exercise One. The EZ-KIT Lite USB emulator, HPPCI-ICE, and ADSP-BF533 processor are used in Exercise Two.
VisualDSP++ 4.0 Getting Started Guide 3-1

Exercise One: Using Profile-Guided Optimization

Exercise One: Using Profile-Guided Optimization
Profile-guided optimization (PGO) is an optimization technique that uses collected profile information to guide the compiler optimizer’s decisions.
Traditionally, a compiler compiles each function only once and attempts to produce generated code that will perform well in most cases. The compiler has to make decisions about the best code to generate. For example, given an
if…then…else construct, the compiler has to decide whether the most com-
mon case is the then or the else. You can offer crude guidelines—compile for speed or compile for space—but, usually, the compiler has to make a default decision.
With PGO, the compiler makes these decisions based on data collected during previous executions of the generated code. This process involves the following steps.
1. Compiling the application to collect profile information
2. Running the application in a simulator session by using representative data sets
The simulator accumulates profile data indicating where the applica­tion spends most of its time.
3. Recompiling the application by using the collected profile data
The compiler uses the collected information rather than the applica­tion’s default behavior to make decisions about the relative importance of parts of the application.
The profile data collected from a simulator run is stored in a file with a .PGO suffix. You can process multiple data sets to cover the spectrum of potential data and create a separate can accept multiple
3-2 VisualDSP++ 4.0 Getting Started Guide
.PGO file for each data set. The recompilation stage
.PGO files as input.
Advanced Tutorial
You must complete these basic steps to use PGO:
1. Build the application with PGO support.
2. Set up one or more streams in the simulator to provide a set of data inputs that represent what the application would see in a real target environment.
3. Tell the simulator to produce a
.PGO file with a specified file name.
4. Load and run the application to produce the .PGO file.
5. Rebuild the application and pass all .PGO files to the compiler, which uses the generated PGO results to optimize the application.
In this exercise, you:
Load the PGO example project in the VisualDSP++ environment
Create data sets for profile-guided optimization
Attach input streams to the data sets
•Create .PGO files by executing the project with the data sets as input
Recompile the project by using the .PGO files to optimize the build
Run the optimized version of the project with the same data sets as input
Compare the execution times of all three executions
The files used for this exercise are in the
pgo folder. The default installation
path of this folder is:
Program Files\Analog Devices\VisualDSP++ 4.0\Blackfin\Examples\ Tutorial\pgo
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Exercise One: Using Profile-Guided Optimization

Step 1: Load the Project

To open a VisualDSP++ project:
1. Start VisualDSP++ and connect to an ADSP-BF533 simulator session. For information about connecting to a session, refer to “Step 1: Start
VisualDSP++ and Open a Project” on page 2-4.
2. Open the PgoExample.dpj project. For details about opening projects, see “Step 1: Start VisualDSP++ and Open a Project” on page 2-4.
This project contains a C file, PgoExample.c. When you run the pro­gram, it reads data from an address and counts the number of even and odd values. This counting is done with an if…then…else statement. If the majority of values read are odd, the program will spend most of its time in the then… branch. If the majority of values are even, the pro­gram will spend most of its time in the else… branch. Normally, the compiler has no way of knowing which branch will be taken more often. By using PGO, the compiler can determine which branch is used most often and optimize the next build.
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This project also contains a Visual Basic script that demonstrates how to use the VisualDSP++ Automation API to perform PGO. The automation functionality is beyond the scope of this tutorial. Refer to online Help for more information about automation.
Three data files are used as input to the C program. These simple text files contain lists of values.
Dataset_1.dat has 128 even values (50%) and 128 odd values
• (50%).
Dataset_2.dat has 192 even values (75%) and 64 odd values (25%).
Dataset_3.dat has 256 even values (100%) and 0 odd values
(0%).
Advanced Tutorial
To view these files, choose the Open command on the File menu in VisualDSP++. The two possible values in all three files are either or
0x02. Each file contains 256 values.
0x01
In this exercise, assume that this program will be used in the real world, and that you can expect a similar distribution of values as input from the real world.
By looking at the C code and the potential input, you can easily see that the executed program will spend more time in the than in the
then… branch. Without using PGO, the compiler cannot
make this same conclusion. By default, it will expect the
else… branch
then… branch
to be executed most frequently and will compile the code without optimizing execution time.
Since the example program and input are very simple, you could fix the problem by making a few minor changes to the code. Manually tweaking a large program to speed up execution time, however, would take far too long, and you would have to analyze sample input on your own. PGO provides a quick and easy way to enable the compiler to make these adjustments for you.

Step 2: Configure a Data Set

The first step in the PGO process is to create a data set—a collection of sample input for the program being optimized. A data set feeds the input into the executing program, and this input causes the program to be executed along certain paths. Some paths will be used more often than others. This information is recorded by the simulator and stored in a compiler to use later for optimization. The most commonly used paths will be optimized to run quickly, and less common paths will run more slowly.
VisualDSP++ 4.0 Getting Started Guide 3-5
.PGO file for the
Exercise One: Using Profile-Guided Optimization
To create the first of three data sets for this exercise:
1. From the Tools menu, choose PGO and then Manage Data Sets, as shown in Figure 3-1.
Figure 3-1. Manage Data Sets Menu Option
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The Manage Data Sets dialog box (Figure 3-2) is displayed.
Figure 3-2. Manage Data Sets Dialog Box
This dialog box is where you manage data sets. Note the Optimiza- tion level slider bar. This control allows you to customize your optimization. Moving the slider all the way to the left enables you to build as small an executable as possible, but may sacrifice execution speed. Moving the slider all the way to the right enables you to build a fast executable, with a potential space tradeoff. Placing the slider between the two extremes provides varying ratios of space versus speed optimization. For this exercise, move the slider all the way to the right.
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Exercise One: Using Profile-Guided Optimization
2. Click the New button to open the Edit Data Set dialog box, shown in
Figure 3-3.
Figure 3-3. Edit Data Set Dialog Box
3. Replace the default Data set name with a more descriptive name. Since the first data file contains an equal number of even and odd values, use a name such as
50% Even – 50% Odd.
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4. Specify the Output filename (where the optimization information produced by this data set will be saved). Optimization information is saved in files with a
.PGO suffix.
Type in a file name such as dataset_1.pgo. The file will be saved in the project directory. To save the files elsewhere, type in a full path name. You can use Command line arguments for more advanced control of the data set, but they are not covered in this tutorial.
For more information about command-line arguments, see the
VisualDSP++ 4.0 C/C++ Compiler and Library Manual for Blackfin Processors.
Now you have to attach an input stream to this data set.
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Exercise One: Using Profile-Guided Optimization

Step 3: Attach an Input Stream

In this step you attach an input stream to the data set.
1. Click the New button to open the Edit PGO Stream dialog box, shown in Figure 3-4.
Figure 3-4. Edit PGO Stream Dialog Box
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An input stream maps a data file to a destination device. In this exer­cise, the input streams map the three data files to the simulator. The input stream provides the program with input as needed during execution.
For more information about streams, see the “Debugging” chapter in the VisualDSP++ 4.0 User’s Guide.
2. Complete the Input Source File group box as described in Table 3-1.
Table 3-1. Input Source File Group Box Settings
Field/Control Action/Value
Filename Specify a file name by clicking the file browse button and selecting the
input source file dataset_1.dat from the pgo directory.
Format The data in this file is in hexadecimal format, so leave the format set-
ting as is.
Rewind on reset or restart Select this option. When you run a program with an input stream, the
program may or may not work through all of the data in the stream. If the program encounters a reset or restart event before working through the entire data stream and this option is enabled, the next execution starts at the beginning of the input stream. Otherwise, execution continues where it left off.
Circular Select this option. It allows the program to read through an input
stream many times during a single execution.
3. In the Destination Device group box, specify where the data from the input stream is sent. Refer to Table 3-2.
VisualDSP++ 4.0 Getting Started Guide 3-11
Exercise One: Using Profile-Guided Optimization
Table 3-2. Destination Device Group Box Settings
Field/Control Action/Value
Processor This field lets you specify a peripheral in another processor as the
destination device. For this tutorial, you are connected to a single processor session, so this field is disabled.
Device This field lets you choose any stream device supported by the simula-
tor target as the destination. Devices can include a memory address or various peripherals. Available devices depend on the processor you are using. For more information on devices, see the hardware manual for your processor. The program reads the input streams from memory, so leave this field as it is.
Address Specify where in memory the input will be sent. Since the program in
this exercise reads data from address
PgoExample.c), enter this value.
0xFFD00000 (refer to
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The completed dialog box should now look like Figure 3-5.
Figure 3-5. A Configured PGO Stream
VisualDSP++ 4.0 Getting Started Guide 3-13
Exercise One: Using Profile-Guided Optimization
4. Click OK to return to the Edit Data Set dialog box. The dialog box with your configured data set should match Figure 3-6.
Figure 3-6. A Configured Data Set
5. Click OK to save the data set and close the dialog box.
You now have to create the remaining two data sets.
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Advanced Tutorial

Step 4: Configure Additional Data Sets

To create the remaining two data sets, you can repeat the steps used to create the first data set and substitute the appropriate files, or use the Copy button.
The following steps explain how to use the Copy button to create a data set.
1. Highlight the
50% Even – 50% Odd data set, and click the Copy
button.
The Edit Data Set dialog box opens with the information for the
50% Even – 50% Odd data set. Clicking the OK button makes a copy
of the 50% Even – 50% Odd data set. For this exercise, however, you will edit the data set.
2. In the Data set name field, specify an appropriate name for the new data set.
The second input source file contains three times as many even values as odd values, so use a name such as 75% Even – 25% Odd.
3. In the Output filename field, type the name dataset_2.pgo to save the .PGO file in the project directory.
To save the file elsewhere, click the file browse button ( ) to specify a full path.
4. In the Input streams box, highlight the dataset_1.dat Input File and click the Edit button.
5. Click the file browse button ( ) to change the Input Source File
dataset_1.dat to dataset_2.dat.
from
6. Click the OK button to return to the Edit Data Set dialog box.
The second data set is now complete.
7. Click the OK button to return to the Manage Data Sets dialog box.
VisualDSP++ 4.0 Getting Started Guide 3-15
Exercise One: Using Profile-Guided Optimization
8. Create the third data set from scratch or modify a copy of one of the existing data sets.
Make sure that you use the
dataset_3.pgo and dataset_3.dat files.
The third data set contains all even values, so give it a name such as
100% Even – 0% Odd. When you are finished, expand the three data
sets listed in the Manage Data Sets dialog box and compare them with the data sets in Figure 3-7.
Figure 3-7. Expanded Data Sets
If your data sets match those in Figure 3-7, you have the data sets needed to optimize the program.
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9. Click OK to save the data sets and close the dialog box.
You are now ready to create
.PGO files.

Step 5: Create PGO Files and Optimize the Program

Now that you have configured the data sets, you are ready to optimize your program.
From the Tools menu, choose PGO and then Execute Data Sets, as shown in Figure 3-8.
Figure 3-8. Execute Data Sets Menu Option
Several things happen during the execute process. First, the project is built with the
–pguide switch, which enables the collection of the PGO data that is
later fed back into the compiler. The compiler makes default assumptions about which sections of code will be most commonly executed. Next, the resulting executable is run once with each data set. While the program is run­ning, the simulator monitors the paths of execution through the program, and the number of cycles used in the execution. As stated before, this information is stored in the
.PGO file that you specified when creating each data set.
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Exercise One: Using Profile-Guided Optimization
Once the program has been run with each data set, the project is recompiled. This time, however, the compiler uses the information found in the to optimize the resulting executable. This optimized executable is then run with the input provided by each data set, and again, the simulator monitors each execution.
You are now ready to examine the results of the optimization.
.PGO files

Step 6: Compare Execution Times

When the execution is completed, an XML report of the PGO optimization results is generated and displayed in a browser window. This file is in the
pgo\debug folder and is named PgoReport.date and time.xml (for example, PgoReport.20031027145428.xml).
At the top of the report is a header, shown in Figure 3-9.
Figure 3-9. PGO Results – Report Header
The header provides basic information such as the project name, location, and when the report was generated. Also listed is the optimization level (which you specified with the slider bar in the Manage Data Sets dialog box, Figure 3-2 on page 3-7), and an average result. The Average result is the difference in total cycle counts on all executions from before and after optimization.
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The Average result obtained on your machine may vary slightly from the result shown in Figure 3-9.
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