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The code perspective and writing code

Code Composer supports assembly code, “classic” C, and C++. For this class we will focus on assembly code and standard C. Most of your coding will happen in the coding perspective, a view where the screen is dominated by a massive text editing window. Code Composer’s editor can be setup in a range from straight forward wyswig to auto-tabbing, auto-highlighting, and auto-completing. Again, explore the options (window→preferences) and find what works best for you and your lab partner.

Writing assembly:

To write assembly in Code Composer, you first need to create a new project following the steps above (be sure to select “ Empty Assembly-only Project ”!). Once you have your empty project, insert a new file (file → new → file). When you input the file name, be sure to give it an “ .asm ” extension. Now that you have your freshly created asm file, you can start writing code in the code window (the big blank white space in the middle of the screen). In assembly mode, code composer parses the column most left as labels, so any non-label code must be indented at least one tab (and conversely labels cannot be indented). You will learn more about the specific components required for a functional assembly file in your specific labs, but in general, you need five common lines. The first, “.cdecls C, LIST, “msp430g2231.h”” defines all of your programming constants (such as P1IN, WDTCTL, etc.). The second “.text” tells the assembler where your actual code begins. The label “RESET” goes at the start of your program so the hardware knows where to begin code execution after a power reset. At the end of your code, you need to leave the memory address of your reset label. To do this, use the command [.sect “.reset”] to tell the compiler you are in the reset section, and then [.word RESET]to place the address of the RESET label into memory.

Writing c:

Code composer really shines writing C and C++. Like in assembly, you will need to create a new project for your new program. This time leave “treat as an assembly-only project” unchecked. Now you will create a new “c source file” (file→ new → source file). When you input the file name this time, be sure to give it a “ .c ” extension. In c mode, you don’t have to worry about line spacing or tabbing for the functionality of the program, just your own sanity and code readability. To include the file you used in the .asm projects that defined all the hardware constants, put the line “ #include “msp430g2231.h” ” at the top of your code. You won’t have to worry about the reset vector or anything like that—the c compiler will take care of it all for you. The only thing actually required in your c program is the function “ void main() {… YOUR CODE… } ”. Other more advanced operations (like interrupts) require special c syntax, but you will cover that in the specific labs when it comes up.

Debug mode, stepping, breakpoints, and watches

Debug mode differentiates an IDE like CCS4 from simpler command line tools. For better or for worse, simply pressing the debug button magically translates your source code into a running program on your attached MSP430. You will notice that after the debugger finally starts up though, your code will not actually be running. This is because the debugger starts in step mode with the first line of your code highlighted. In other words, the hardware is waiting for you to let it execute that one line of code, so your slow human reflexes can process and verify what it can do in a fraction of a second. Stepping through your code one line at a time helps you find subtle errors and see exactly where a program goes off track. Yes, as you can imagine, simply stepping through a real world multi-thousand line program (or the larger programs you will write later in this course) is inefficient and unfeasible. Breakpoints allow you to tell the debugger to stop if/when the processor gets to a certain point in your code, letting you run quickly through the code you trust and only stop at certain problematic sections you want to look into more closely. You can set several breakpoints at once, and once the program has broken, you will be able to actively see all register and memory values and step through line by line just as if you had started step mode at your break point. Watches are a little bit more abstract and more useful for larger programs, but they allow you to set a watch on a particular variable (in c) or memory location/register (in asm) and only break the program when it tries to change that particular value. This can help you find where exactly where and when a value changes into an erroneous state.

Using a combination of breakpoints, watches, and careful stepping, you can pick apart any complicated program to hunt down errors and really understand what goes on during the program’s execution.

Questions & Answers

what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
How can I make nanorobot?
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
how can I make nanorobot?
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
in a comparison of the stages of meiosis to the stage of mitosis, which stages are unique to meiosis and which stages have the same event in botg meiosis and mitosis
Leah Reply
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Source:  OpenStax, Intro to computational engineering: elec 220 labs. OpenStax CNX. Mar 11, 2013 Download for free at http://cnx.org/content/col11405/1.2
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