C Programing Language Doccumentation

Hi Peter

From what I can recall "sleep()" is a OS (operating system) API function. There is no such functionality in TI's  C implementation that I know of (I may be wrong).

One possible solution is to used US_DELAY macro, which is included in DSP's Preipheral header files and examples - check the ADC example code. Thou it works, you must be warned, that this code actually executes a loop for n-times in order to achieve desired delay. If some interrupt happens within the loop, the delay will thus be longer for a interrupt processing time. Not an accurate way to generate delays.

The other possibility is to use a RTOS package (DSP/BIOS comes to mind), which provides such an API call

For the documentation check the following documents: SPRU514C and SPRU625

I hope this helps

Regards, Mitja

Hey Mitja

Thank you for taking the time to answer my questions. I have found some of what i was searching for, in SPRU514, in which there is a chapter called "TMS320C28x C/C++ Language Implementation". This chapter explains alot about e.g. datatypes that is useful if you don't have that much experience with programming C for MCUs. I was unable to find the "US_DELAY" macro you are talking about, so for now i'll stick to the solution I'm using, with a timer and a loop.

I have another question which i don't think is touched that much by the documentation: Interrupts. The topic is somewhat covered in SPRU514, but i have no idea of how to actually implement interrupt handling, since there are no examples. For instance, when a timer generates an interrupt, i would like to run the function interrupt_function1(). From what i read, you need to implement the function like

#pragma INTERRUPT (interrupt_handler);

interrupt void interrupt_handler()
{
unsigned int flags;
...
}

SPRUFN3C ( TMS320F2802x/TMS320F2802xx Piccolo System Control and Interrupts) tells a lot about interrupts and how they work, and it is clear that somehow you need to specify which code to run when the different interrupts are raised. But i have no idea how to do that. I can't find any examples in the code examples, that uses CPU interrupts.. Have i missed something? Where can i find info on this?

best regards

Peter C

Hi Peter

Sorry about the name of the delay macro. it is DELAY_US and NOT the US_DELAY (I make this kind of mistakes happen a lot lately). The function it calls is in the "DSP2802x_usDelay.asm", while the macro is define in "DSP2802x_Examples.h".

Regarding the interrupts I found that the best example of interrupt code is in "Example_2802xCpuTimer.c". You can see how the interrupt function address is put in PIE vector table (lines 112-114), how the interrupt is enabled within PIE (line 164), how different interrupts are enabled within the CPU (lines 159-161) and how interrupts are enabled globally (line 167).

When you cover this we can further discuss the ERTM instruction (line 168) and its impact on debugging.

One other thing. If you use interrupt keyword with function declaration, you do not need to use #pragma extension. It is one or the other.

Hope this helps, Mitja

Peter,

You can download the examples Mitja mentions here:

http://focus.ti.com/docs/toolsw/folders/print/sprc832.html

-Lori

For Piccolo, I recommend our new controlSUITE

www.ti.com/controlSUITE

Once you install and select the F2802x series (and I recommend the controlSTICK as well) you'll find DSP2802x_usDelay.asm here:

C:\ti\ControlSUITE\device_support\f2802x\v125\DSP2802x_common\source

Hello everyone

Thank your for your answers.I will look at the delay system ASAP, but for now i'll just use the one i created. I do however find it a bit confusing, that there are several example collections. On the CD  that came with the stick, there are 2 examples "simpleDACtoADC" and "blinkingLED". Then i found another example library, which included comparator, ADC and PWM examples(installs to the same path as the one from the stick: c:\Texas Instruments\Piccolo controlSTICK\). And now i found a third one, which i guess are the ones you talk about, which installs to C:\tidcs\c28\DSP2802x\v121, and is called "DSP2802x header files and examples".  I'll try to install the controlSUITE program and see what comes from that.

Best regards

Peter

Peter,

I understand your confusion.

Your Piccolo controlSTICK CD only comes with the simple DAC to ADC and LED demo.  After this tool was released we created more examples that we placed on the website. (it looks like you found those).

When we release a device series we also include a set of Header Files and Code Examples that work agnostic of any of our development tools.  For F2802x this is here: http://focus.ti.com/docs/toolsw/folders/print/sprc832.html

What we are doing as of yesterday with our controlSUITE announcement is giving customers a single place to go for all their software needs.  The controlSUITE installer will always show you everything that's available for a given device or development tool, and it re-organizes everything into a common file structure.  This will ensure that what you went through doesn't happen again. You will always know WHAT is available, and you will always have the latest collateral and revisions as soon as we place them on our server.  

http://www.ti.com/controlsuite