Just enough information to program a Blackfin
Familiarization assignment for the Analog Devices’ VisualDSP++Integrated Development Environment
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 2 / 27
This will help to get ahead on the assignments
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 3 / 27
Tackled today
Recipe for Just in time knowledge Need a dollop of “C++” code A smizzen of knowledge to build the
simplest possible Blackfin assembly language for-loop { } and while { }
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 320.
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 4 / 27
VisualDSP++ IDE
Analog Devices’ integrated development environment (IDE) has been used in the following courses
Blackfin – ADSP-BF533 ENCM415 – Assembly language and interfacing (2004) ENSF413 – Switching to Blackfin for 2008 ENCM491 – Real Time Systems (2003) ENCM511 – New project oriented microcontroller course (2008) ENEL619.23 -- High speed embedded system architectures (2004) ENEL583/589 – Many 4th year team projects (2004)
TigerSHARC – ADSP-TS201 ENCM515 – Comparative Processor Architectures for DSP (Since
1999) ENEL619.23 -- High speed embedded system architectures (2004)
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 5 / 27
Just enough to know If time today will do a demo.
Build a directory <HOME>:/ENCM415/Assignment Remember to insert the BF533 board power plug (check that lights
on board flash) Activate VisualDSP -- Log into a station and use Analog devices
CONFIGURATOR to set up a “BF533 session” to connect to the hardware Use VisualDSP++ and activate a Blackfin BF533 session – lights should
pause
Build a Blackfin Project, add to your directory Add your C++ files to the project Compile, Link and Run using the equivalent commands as with Microsoft
Visual Basic, Visual Studio etc
Add your assembly ASM files to the Blackfin project Compile, Link and Run using the equivalent commands as with Microsoft
Visual Basic, Visual Studio etc
Don’t forget to add some tests so that you know the code is working
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 6 / 27
Analog Devices CONFIGURATOR
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 7 / 27
Run VisualDSP – Add New Project
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 8 / 27
WRITE main.cpp, ADD to Project
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 9 / 27
Then BUILD (which causes a LOAD)
Build and load
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 10 / 27
Then Debug | Run the code
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 11 / 27
Prepare for Assignment – C++ result
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 12 / 27
C++ Version of an assignment
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 13 / 27
“auto-increment” of a pointer. Here is how to “try” to get compiler to do it
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 14 / 27
Prepare main( ) to call assembly codeand CHECK the results
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 15 / 27
We thought we needed to build the function Assignment1_ASMversion( )
However the linker is worried about not finding _Assignment1_ASMversion__Fv
Build WITHOUT ADDING assembly code fileError message is VERY SPECIAL
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 16 / 27
Standard Format “Assembly code” stub assignment1ASM.asm
Header info
Prologue
Code toreturn value
EpilogueA “stub” provides “just enough code” not to crash the development system.
It acts as a “test” for the correct call from “main()”
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 17 / 27
Result using “Assembly code” stub
Exactly the result we expected
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 18 / 27
Keyword – R0 – 32-bit Data Register
R0 = 7; // This returns value 7 …
Assembly code comment
End of line marker
32 bit data register -- R0, R1, R2, R3, R4, R5, R6, R7
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 19 / 27
Keyword – P0 – 32-bit pointer Register
32 bit pointer register -- P0, P1, P2, P3, P4
Careful – when not in the assembler, the linker may give errors which mention p0 which stands for processor 0. The blackfin hardware can come in multi-core version (p0 and p1 for BF561) or multi-processor version.
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 20 / 27
Keyword 32-bit Frame pointer
32 bit Frame pointer -- FP
As on many processors LINK and UNLINK instructions
involve hidden operations on FP and SP (stack pointer)
More on that in a later class
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 21 / 27
Keyword – Memory operations
32 bit memory read [ ] – long-word access R0 = [FP + 4];
If FP contains the value 0x20000000 then fetch the 32-bit value starting at memory location 0x20000004 and place in data register R0
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 22 / 27
Keyword – Memory operations
16 bit memory read W[ ] –word access R1.H = W[FP + 28];
If FP contains the value 0x20000000 then fetch the 16-bit value starting at memory location 0x20000028 and place in data register R1.H which is the UPPER part of the register R1 (R1.H and R1.L)
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 23 / 27
Keyword – Memory operations
8 bit memory reads are also possible B[FP + 4];
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 24 / 27
Perhaps time for a working example
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 25 / 27
Programmer’s model
32 bit data register R0, R1, R2, R3, R4, R5, R6, R7
16 bit data register R0.H, R1.H, R2.H, R3.H ……. R7.H R0.L, R1.L, R2.L, R3.L ………. R7.L
32 bit Pointer register (“address”) P0, P1, P2, P3, P4
NO 16 bit Pointer (“address”) registers You need to have 32 pointers to access 16-bit
values stored ANYWHERE in the memory 32 bit Frame Pointer -- FP 32 bit Stack Pointer -- SP
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 26 / 27
Memory access MUST be done via a Pointer register
32-bit Memory access Place value 0x2000 into register P1 THEN R0 = [P1] accesses (reads) the 32-bit value at
0x2000 and leaves P1 unchanged (P1 still equals 0x2000)
R0 = [P1 + 4] accesses (reads) the 32-bit value at 0x2004 and leaves P1 unchanged (P1 still equals 0x2000)
R0 = [P1++] accesses (reads) the 32-bit value at 0x2000 and autoincrements P1 by the size of a long word (4 bytes) (P1 NOW equals 0x2004)
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 27 / 27
Memory access MUST be done via a Pointer register
16-bit Memory access Place value 0x4000 into register P2 THEN R0 = W[P2] accesses (reads) the 16-bit value
at 0x4000 and leaves P2 unchanged (P2 still equals 0x4000)
R0 = W[P2 + 4] accesses (reads) the 16-bit value at 0x4004 and leaves P2 unchanged (P2 still equals 0x4000)
R0 = W[P2++] accesses (reads) the 16-bit value at 0x4000 and autoincrements P2 by the size of a word (2 bytes) (P2 NOW equals 0x2002)
M. Smith -- ENCM415 Assembly Language and Interfacing on the Blackfin ADSP-BF533 microcontroller 28 / 27
Just enough to know If time today will do a demo.
Build a directory U:/ENCM415/Assignment Remember to insert the BF533 board power plug (check that lights
on board flash) Activate VisualDSP Log into a station and use Analog devices
CONFIGURATOR to set up a “BF533 session” to connect to the hardware Use VisualDSP++ and activate a Blackfin BF533 session – lights should
pause
Build a Blackfin Project, add to your directory Add your C++ files to the project Compile, Link and Run using the equivalent commands as with Microsoft
Visual Basic, Visual Studio etc
Add your ASM files to the project Compile, Link and Run using the equivalent commands as with Microsoft
Visual Basic, Visual Studio etc
Don’t forget to add some tests so that you know the code is working
Top Related