1. VisualDSP++ and Test Driven Development What happened last lecture?
Note – Developing the C++ Rectify code will be part of Familiarization Lab. and Pre-lab 1 Assignments

2. Concepts of TDD, M. Smith, ECE, University of Calgary, Canada
Developing software radio on the TigerSHARC
Concept of test driven development – An “Agile” software development concept
Writing the customer tests
Understanding the E-TDD testing framework
Writing the CPP rectify code
Will be trying these ideas out in the laboratory this afternoon.
12/31/2018
Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

3. Conventional “AM” radio
RF STAGE
Antenna
Pickup
AUDIO STAGE
Low pass Filter + amplifier
Low pass Filter
Rectifier
Mixer
Local Oscillator
IF STAGE
Audio out
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

4. Software “AM” radio concept
RF STAGE
Antenna
Pickup
AUDIO STAGE
Low pass Filter + amplifier
Low pass Filter
Rectifier
Mixer
Local Oscillator
IF STAGE
Audio out
Most stages handled with high speed software
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

5. A basic example for the coding practices adopted through the term
Going to use the rectification stage of this “soft-radio” as a “code example” all through the course.
We may also look at “single-side band modulation” (involves IIR filtering) as a second “code example” followed all though the term.
12/31/2018
Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

6. Customer Requirements
Wants to get “product out of the door” as fast as possible
Less time spend on development the better, but it has to work
Developing in C++ is easier than developing in assembler code, but is it fast enough
Risk analysis – take one representative part of the code and explain the differences between the speeds from C++ code (Debug and Release Mode) and assembly code
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

7. Standard testing practice
Heavy on documentation
TLD
Test Last Development
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

8. Test Driven Development
Work with customer to check that the tests properly express what the customer wants done. Iterative process with customer “heavily involved” – “Agile” methodology.
CUSTOMER
DEVELOPER
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

9. Lets apply TDD to rectification issue
Overall technique
Decide on a particular test action with the customer
Write the test(s)
Write the simplest possible code to satisfy the test(s)
“Refactor” the code to improve “quality”
Definition of “quality” is unclear in the literature
Ease of “use” or “reuse” of code
Reliable to use – “robust”
My additional idea – meets speed requirements for the embedded situation
See paper handed out for more details
12/31/2018
Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

10. Files and directories needed TDD and many tests files available on web
ENCM515 WEB
Rectify Tests – Assign1Tests
HalfWaveDebugModeTests.cpp
HalfWaveReleaseModeTests.cpp
HalfWaveAMSTests.cpp
TDD files in E-TDDIncludes dir
ActivateTests.cpp
TS201_char32_TDDLib_dlb
Various TDD_includes.h
TDD_Tests1Jan05.h
Rectify code developed in Assign1 directory
Rectify.h
TS201.ldf (loader description file for 1 processor)
HalfWaveDebugMode.cpp (float and int code)
HalfWaveReleaseMode.cpp (float and int code)
HalfWaveIntASM.asm
HalfWaveFLoatASM.asm
Lab1
Lab1Tests
Lab2
Lab2Tests
LabX
LabXTests
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

11. Concepts of TDD, M. Smith, ECE, University of Calgary, Canada
E-TDD Test.cpp files have four main components. Many error messages if not present
Include Files – cut-and-paste (always the same)
TEST_CONNECT (TestFileInfo)
TEST(testNAME, testTYPE)
NOTE: Tests execute from LAST in file to FIRST. As normally the LAST test is the most recently added test, this is good.
You test if new code works and then check (regression test) that you did not break anything
LINK_TEST(TestFileInfo, testTYPE)
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

12. Now expand the Customer Tests to do what the customer has requested
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

13. Now expand the Customer Tests to do what the customer has requested
E-TDD TEST SYNTAX
CHECK( ) – if condition is true
XF_CHECK( ) – expected failure meaning you know its wrong and plan to fix later. Passing an XF_CHECK( ) (SUCCESS) is considered a failure. ARRAYS_EQUAL( ) – basically a loop of CHECK( )s.
MEASURE_EXECUTION_TIME( ) automatically uses an internal TigerSHARC clock. Value returned in “processor cycles”.
REPORT – currently printf( )
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

14. Concepts of TDD, M. Smith, ECE, University of Calgary, Canada
Note that writing the tests has automatically generated the function interface information
Why int* and float* rather than just void as you are passing in the address of the output
Design decision – sort of standard with “C” to pass back a pointer to thing being changed
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

15. Concepts of TDD, M. Smith, ECE, University of Calgary, Canada
Floating point version of the Tests Essentially a cut-and-paste version of integer code
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

16. Stage 1 – Compile / Link the tests
Obviously the Link is not going to work – as the code for functions HalfWaveRectifyXXX( ) have not been written
If obviously going to fail – WB (why bother)?
Basically – You are TESTING THE TESTS
Are you calling the functions you expect to call.
Better handled by doing Code Review first, and then use compiler / linker to CHECK the Code Review did not miss something (PSP – personal software process).
C++ can overload function names (done via name mangling).
What are the name-mangled names needed for the assembly code? – This stage will show you.
12/31/2018
Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

17. Name mangled names can be seen from linker
C++ name as used The name mangled name generated by
in C++ code by the C++ compiler in response to function
overloading. These are the “assembly code”
names
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

18. Next step: Write just enough code to satisfy the linker – C++ stubs
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

19. Write the assembly language stub
We lost control of the processors in the debug environment.
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

20. Concepts of TDD, M. Smith, ECE, University of Calgary, Canada
Recovery process
Don’t lose control – write good code
Do incremental builds so you are continually writing and testing code
E-TDD encourages this – write a test, then write just enough code to satisfy the tests
If you lose control
Try selecting each processor (DSPA then DSPB) in processor window. Then select DEBUG | HALT
If that fails, then in this order (easier restart process)
Exit from E-TDD GUI,
Exit from VisualDSP IDDE
Power down the board
Walk-around your chair twice (or count to 10) 
Power up board, then reactivate VisualDSP IDDE and the GUI
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

21. We “accidentally” pass some tests without writing any code
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

22. Concepts of TDD, M. Smith, ECE, University of Calgary, Canada
Write “just enough code to satisfy” Cpp tests. During design may identify more tests.
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

23. Build the code incrementally to satisfy tests
See speed change now we
Are executing code – but why failures
Note what if N < = 0
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

24. Concepts of TDD, M. Smith, ECE, University of Calgary, Canada
Add test to check that works if N <= 0 Do another code review and spot problemS
NEW TESTS
CHECKING WRONG THING
OVER-WRITING EXPECTED RESULTS
12/31/2018
Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

25. Concepts of TDD, M. Smith, ECE, University of Calgary, Canada
Weird test results
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

26. Concepts of TDD, M. Smith, ECE, University of Calgary, Canada
Weird test results
I forgot to add the new code for the pt = NULL if N <= 0, yet some tests pass
ASM passes since stub sets pt = NULL before returning
I did not do any assembly code – yet the tests act as if the code is working
Release code passes
ASM code passes
Poor test design because we did not set the “result_array[ ]” back to zero
FIX THE TEST AS PART OF ASSIGNMENT 1
12/31/2018
Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

27. Incrementally added the code to HalfWaveReleaseMode( )
Test that past before are now failing
Compiler does not know difference between “debug” and “release” mode
12/31/2018
Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

28. Select file – then right click and select FILE OPTIONS
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

29. Click on “File Specific Settings” and then on COMPILE | General
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

30. Click on ENABLE OPTIMIZATION, Click okay and then rerun the tests
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Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

31. Concepts of TDD, M. Smith, ECE, University of Calgary, Canada
Note
Special marker
Compiler optimization
FLOATS 927  THREE FOLD
INTS 960  150 – SIX FOLD
Why the difference, and can we do better, and do we want to?
Note the failures – what are they
12/31/2018
Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

32. Concepts of TDD, M. Smith, ECE, University of Calgary, Canada
Use GUI to find out
Okay – at this point in time – we are expecting that to fail
12/31/2018
Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

33. Concepts of TDD, M. Smith, ECE, University of Calgary, Canada
Concepts tackled
Developing software radio on the TigerSHARC
Concept of test driven development – An “Agile” software development concept
Writing the customer tests
Understanding the E-TDD testing framework
Writing the CPP rectify code
Will be trying these ideas out in the laboratory this afternoon.
12/31/2018
Concepts of TDD, M. Smith, ECE, University of Calgary, Canada