Hello,

I have a very simple question that should be very easy to answer, but first I'd like to provide
a bit of background on where I am coming from. Feel free to skip over this if you like.

<< Begin Background >>

Although I have had three DSP classes none of these courses exposed me to any type of DSP
embedded programming.  I have never programmed a DSP chip before because all my time, to date,
has been spent on theory (Z-transforms, basics on IIR & FIR filters, using MatLAB for
design of filters and plotting, understanding differences of DFT and FFTs (as well as other
computationally efficient transforms) and even a small bit on polyphase filters).  I found all
of this stuff absolutely fascinating, but I have no practical experience.

In an effort to gain real experience I have decided to spend time learning how to use the
TMS320VC5510 DSK evaluation board along with Code Composer (ver. 3.1.0).  My background is very
limited with regards to programming, however I have taken a few required classes in C
programming as well as an assembly course (for the Motorola 6800 – a very old microprocessor
from the 1970s).  I should be reasonably functional to start.

<< End Background >>

In Code Composer I found a way to operate the LED by writing directly to the CPLD on the
Evaluation board (the CPLD is used for memory decoding as well as controlling the user input
switches and LEDs).  I did this from Code Composer by pressing

View --> Memory...

to bring up the Memory Windows Options dialog box then entering the address

0x300000

into the field that says address. After pressing OK another dialog box comes up showing memory
values in HEX from address 0x300000 to 0x300250. From this window you can change the lower
4-bits of the 16-bit memory location to control the LEDs.  

Now, I would like to write a program to blink the LEDs (or control them in some way).   I am
not sure what would be the easiest way to do this. 

Any suggestions? 

Would anyone care to show how I could write to address 0x300000 using C in Code Composer?

I don't know if this is a good idea or not, but I did consider writing a few lines of assembly
within C code that would directly write to this address. I could do this by hacking into an
existing C source code that can be compiled and run on the C5510 DSK.  If this is a reasonable
approach then I would need to know the command to write in-line assembly code in a C file.

Joe

DSP, in my view, is 2 parts of the same game:  theory and implementation.
You have the theory, which is good.  Now you are learning the
implementation, which is just as challenging ( and fun! )

Here is an example of how I write to the CPLD register using C, for a 6713
DSK:

*(unsigned volatile int *)DSK_CPLD = 0x00030010;

With your c55 kit, there should be some header file like hw.h, where the
addresss of the CPLD is defined.  For a 6713 DSK I have, it is defined as
0x90080004.  It will likely be different for the C55.

For the C55, I also write to some internal registers like this:

*(ioport volatile unsigned int *)DXR1_1 = 0x0000;

All of this can be done in assembly as well.  The inline assembly command is
asm( "instruction" ).  But you could find this in the C55 manuals that are
located at www.ti.com.  I encourage you to find these manuals, and use them
as reference.

Regards,

Robert

www.greatlakessignalprocessing.com
-----Original Message-----
From: c...@yahoogroups.com [mailto:c...@yahoogroups.com] On Behalf Of
j...@yahoo.com
Sent: Saturday, September 02, 2006 11:56 PM
To: c...@yahoogroups.com
Subject: [c55x] Example Program for TMS320VC5510 DSK - controlling LED

Hello,

I have a very simple question that should be very easy to answer, but first
I'd like to provide a bit of background on where I am coming from. Feel free
to skip over this if you like.

<< Begin Background >>

Although I have had three DSP classes none of these courses exposed me to
any type of DSP embedded programming.  I have never programmed a DSP chip
before because all my time, to date, has been spent on theory (Z-transforms,
basics on IIR & FIR filters, using MatLAB for design of filters and
plotting, understanding differences of DFT and FFTs (as well as other
computationally efficient transforms) and even a small bit on polyphase
filters).  I found all of this stuff absolutely fascinating, but I have no
practical experience.

In an effort to gain real experience I have decided to spend time learning
how to use the TMS320VC5510 DSK evaluation board along with Code Composer
(ver. 3.1.0).  My background is very limited with regards to programming,
however I have taken a few required classes in C programming as well as an
assembly course (for the Motorola 6800 - a very old microprocessor from the
1970s).  I should be reasonably functional to start.

<< End Background >>

In Code Composer I found a way to operate the LED by writing directly to the
CPLD on the Evaluation board (the CPLD is used for memory decoding as well
as controlling the user input switches and LEDs).  I did this from Code
Composer by pressing

View --> Memory...

to bring up the Memory Windows Options dialog box then entering the address

0x300000

into the field that says address. After pressing OK another dialog box comes
up showing memory values in HEX from address 0x300000 to 0x300250. From this
window you can change the lower 4-bits of the 16-bit memory location to
control the LEDs.  

Now, I would like to write a program to blink the LEDs (or control them in
some way).   I am not sure what would be the easiest way to do this. 

Any suggestions? 

Would anyone care to show how I could write to address 0x300000 using C in
Code Composer?

I don't know if this is a good idea or not, but I did consider writing a few
lines of assembly within C code that would directly write to this address. I
could do this by hacking into an existing C source code that can be compiled
and run on the C5510 DSK.  If this is a reasonable approach then I would
need to know the command to write in-line assembly code in a C file.

Joe