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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

Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Elec 220 lab course (escape). OpenStax CNX. Apr 07, 2013 Download for free at http://cnx.org/content/col11513/1.1
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