about RTI,I need an example-urgent_MC13213

[Beijing2008]

Hi all:

I'm using MC13213 and CW6.1,Now I would like to generate a timer,trigger a timer interrupt per N*second.

how to use the RTI(real-time interrupt)? please give me an simple example!

thanks and best regards,
Charly

[bigmac]

Hello Charly,

I will assume that you have set up the RTI module to generate an interrupt once per second.  Then your ISR might contain the following code -

if (tcounter) {

   tcounter--;

   if (!tcounter) {

      // Do timeout action here

   }

}

where tcounter is a global variable of a suitable size.  To commence a timeout period, set the value of tcounter to the number of seconds required.  If the action required on timeout is too time consuming to be included within the ISR, you would need to poll for the occurrence of timeout - simply test whether the global variable has reached a value of zero.

Regards,

Mac

[Beijing2008]

Hi bigmac :

  Thanks for your help!
  I'm sorry that the above description is not clear enough!

  It's sure that I don't konw how to set up the RTI module for generating a RTI interrupt,such as the SRTISC register or need other registers!
  The following code is a small test program,compiler under the CW6.1 and MC13213.

#include <hidef.h>
#include "derivative.h"

void Init_RTI(void)
{
 SRTISC=0xff;  //set up the SRTISC register,how to config it?
}

void Init_IO()
{
 PTDD_PTDD4 = 1; 
   PTDDD_PTDDD4=1; //output,for lighting a led
}

void main(void) {
  Init_RTI();
  Init_IO();
  EnableInterrupts;
  for( ; ; )  {
    __RESET_WATCHDOG();
  }    
 
}

interrupt VectorNumber_Vrti void RTI_ISR(void)  //RTI interrupt,but cann't be trigger here,WHY?
{
  if((SRTISC&0x80)==0x80){
   SRTISC_RTIACK=1;              //clear
   PTDD_PTDD4=~PTDD_PTDD4;  //on or off
  }
}

Running it,but the led was never lighted,I think the RTI module initializtion is wrong!

Please give me some hints!

Thanks again.

Best regards,
Charly

Message Edited by Beijing2008 on 2008-07-31 04:47 AM

[bigmac]

Hello Charly,

It is possible that you do not have the correct RTI clock source selected, and this will depend on the operating mode when RTI operation is required.  According to the datasheet, there are the following restrictions for the clock source -

Run mode - External reference clock only

Wait mode - External reference clock only

Stop3 - Either clock source

Stop2 - Internal RTI clock only

Stop1 - RTI inoperative

Assuming your tests use run mode, you will need to provide an external reference signal, and set the control bit SRTISC_RTICLKS.

Regards,

Mac