laboratory 1 – encm415 familiarization with the analog devices’ visualdsp++ integrated...

Laboratory 1 – ENCM415

Familiarization with the Analog Devices’ VisualDSP++Integrated Development Environment

M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller

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Lab. 1 -- this afternoon

Recipe for Just in time knowledge Need a dollop of “C++” code from

assignment 1 main( ), HelloWorldTest( ), MeasureTemperature( ) Hopefully you’ve just handed-in working code at the

start of the class A smizzen of knowledge to build the simplest

possible Blackfin assembly language for-loop A pinch of Window’s Experience And a bowl to put the ingredients in (a

computer account with password) and somebody else to do all the clean-up (a partner) and a desk in Labs ICT318 and 318.


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VisualDSP++ IDE

Analog Devices’ integrated development environment (IDE) ENCM415 – Assembly language and interfacing (2004) ENCM491 – Real Time Systems (2003) ENCM505 – Multi-processor course (2004) ENCM515 – Comparative Processor Architectures for

DSP (Since 1999)

Dr. Smith has been awarded the Analog Devices’ University Ambassadorship for 2001/2002, 2002/2003, 2003/2004


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Just enough to know

Build U:/ENCM415/Lab1 Directory Activate VisualDSP++ 16-bit processor Family

simulator session and activate a Blackfin simulator session

Build a Blackfin Project, add to your directory Add your Assignment1 C++ files to the project Compile, Link and Run using the equivalent

commands as with Microsoft Visual Basic, Visual Studio etc

If time today will do a demo.


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Blackfin C++ code STUB

A function stub has just enough code to Compile, link and run

int main(void) { unsigned short int timeUsed1, timeUsed2;

HelloWorld(FRANCE); timeUsed1 = UseTime(0x5000);

timeUsed2 = UseTimeASM(0x5000);}


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Valid main stub

int main(void);void HelloTest(const short int);

typedef unsigned short int ushort; // Define a variable typeushort UseTime (ushort int);extern “C” ushort UseTimeASM(ushort int);

#define FRANCE 5void int main(void) { ushort timeUsed1, timeUsed2; HelloTest(FRANCE); timeUsed1 = UseTime (0x5000); timeUsed2 = UseTimeASM(0x5000);}


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HelloTest

You provide the stub needed for the “C++” function HelloTest( )

Note that you don’t need to know any details of the function (other than its prototype) to build a stub


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ushort UseTime(ushort);

This routine is written in “C++” It must return a value

When first developing the code – return an error value

You write the stub


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ushort UseTimeASM(ushort);

The customer wants this written (for some reason) in assembly code

It is “assembled” and not “compiled” However activating the compiler will cause the

assembler to be activated automatically Place in a file with extension “.asm” and

add to your project – UseTimeASM.asm Have you seen the expression “extern C”

used in a program before? What does the stub look like?

See Lab. 1 web pages for more detail Why does the stub look like that?


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Assembly code Stub in file UseTimeASM.asm

#include <defBF533.h>#include <macros.h> .section program; .global _UseTimeASM; .align 2;#define UseTimeASMSTACK 16 _UseTimeASM: // unsigned short int UseTimeASM(unsigned short int timeToUse) { LINK UseTimeASMSTACK; // Code goes here and replaces next line R0 = 0; // return 0;

P0 = [FP + 4 ]; UNLINK; JUMP (P0); // }_UseTimeASM.end:


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Code for ushort UseTime(ushort); First thing – compile and link the stubs, check that they work

(run). Provide the “C++” code for ushort UseTime(ushort);

It must return the parameter passed to it It must “waste time” accurately – meaning that

UseTime(2000) must take twice as long to execute as UseTime(1000) (to within a certain error limit)

Then develop the simplest code needed – get that to work How can you “check” that it works?

Then “refactor” the code -- and add quality to the code – check that still works

Don’t use a “for loop” – since we know from MIPS experience that assembly code does not support “for loops”

Actually the Blackfin BF5xx processor family DOES support a maximum of 2 hardware loops in assembly code – but that is not many


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Code for ushort UseTimeASM(ushort);

First thing – compile and link the assembly code stubs, check that they work (run).

Get the “C++” code for ushort UseTime(ushort); to work

Now translate that code (one line at a time) into assembly code ushort UseTimeASM(ushort); using the “C++” code as “comments” . Techniques for Control Code (CC) Bit Management

are detailed in Section 6 of the Blackfin Processor Instruction Set Reference.

Arithmetic operations are detailed in Section 10 of the Blackfin Processor Instruction Set Reference.

More details can be found in Task 6 of Laboratory 1


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VisualDSP – working example

Now lets put some of these ideas together as a working demo

Note – more slides walking you through setting up a VisualDSP session follow – your responsibility

A little hint for the laboratories Check the performance of the simulator before

and after code optimization – that is “DEBUG MODE” (before) and “RELEASE MODE with DEBUG information” (after)


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Activating VDSP environment

Hold CONTROL key down while activating to ensure that you get a choice of session to use

Lab. 1 session – Blackfin Family simulator


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Activate required session


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Select new project, save .dpj file


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Project Options


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Say no here – or start again


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Add your main.cpp file to the project


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Display in window and set Editor tab


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Build project

Build file in window, if the file is in the project

Build project (only changed files rebuilt and will cause load if successful)

Rebuild all files whether changed or not

Click here to jump to error in source file


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Build, Load, Run


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After running

NOTE: Disassembly window shows that program has found the C++ stop here optionDON’T ACTIVATE “RUN” AGAIN

String in output window


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Mixed mode allows you to see “C++” source and equivalent assembly code

RIGHT-CLICK IN SOURCE WINDOW


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Mixed mode allows you to see assembly source code and assembly

Debug assembler option must be ON


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Other useful VisualDSP++ options

MEMORY DISPLAY

REGISTER DISPLAY

PLOT WINDOW


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Tackled today

Just enough information to activate a simulator session for Lab. 1


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Information taken from Analog Devices On-line Manuals with permission http://www.analog.com/processors/resources/technicalLibrary/manuals/

Information furnished by Analog Devices is believed to be accurate and reliable. However, Analog Devices assumes no responsibility for its use or for any infringement of any patent other rights of any third party which may result from its use. No license is granted by implication or otherwise under any patent or patent right of Analog Devices. Copyright Analog Devices, Inc. All rights reserved.

laboratory 1 – encm415 familiarization with the analog devices’ visualdsp++ integrated...

Documents

assembly code

blackfin c code stub

stub slide

blackfin project

ushort timeused1

encm415 familiarization

blackfin simulator session

function stub