MSP430f149 timer

Manmesha,

i am not sure whether i understand your problem completely. Maybe if you could provide your code that will be helpful to understand how you do the polling.

However i also see that the information you gave is somehow confusing. You said that you are using SMCLK to source the Timer_A (TASSEL_2), and the SMCLK is 32768 Hz. Referring to the User's Guide document, Figure 4-1 the Basic Clock Block Diagram, you can see that SMCLK can only be source from either DCO or XT2 by selectin SELS bit. The XT2 itself only accepts 1-8MHz frequency. So the question is what do you exactly mean by using 32768 Hz SMCLK?

-Leo-

hi,

 Thanks for your  reply....

Yes, u r right. SMCLK uses the DCO clock. But according to my info DCO frequency is= 32768Hz. !!!

#include "io430.h"

 //#include <io430x11x1.h> // Specific device
//#include <msp430f149.h>
// Pins for LEDs
#define LED1 BIT3
#define LED2 BIT4
#define SW1 BIT0
#define B1 BIT1
unsigned int x,i,w;



void delay_1_sec(void)

{
      int i,x;
     
      x=0;
     // WDTCTL = WDTPW|WDTHOLD; // Stop watchdog timer
      P2OUT =  LED1; // Preload LED1 on , LED2 off
      P2DIR = LED1|LED2; // Set pins for LED1 ,2 to output
      TACTL = MC_2|ID_0|TASSEL_1|TACLR; // Set up and start Timer A
// Continuous up mode , divide clock by 8, clock from SMCLK , clear timer
      //for (;;)
     
     
      do
     // {   
      //for(i=0; i<1; i++)
     { // Loop forever
         {
            // do
       //{

        if(( P1IN & SW1)==0)
                  {
                    
     
                               do
                                   {
                                     P2DIR=   0X0a;  // PORT PIN P1.1 IS SET AS OUTPUT PIN
                                       P2OUT = 0x0a;  //set the LED connected to the port pin p2.3(timer led  1sec ) and p2.1 (not connected)
                             }while ((P1IN & SW1)==0);  
                                            
                                         x=x+1;    
                      }            
        else
         {
              P2DIR=   0X0a;  // PORT PIN P1.1 IS SET AS OUTPUT PIN
              P2OUT = 0x08; // only timer led is on and the led for switch is off.
         }
        //do
     //    {
        //     } while ((P1IN & SW1)==0);  //wait till the switch is released...
   
            //P2DIR=   0X0a;  // PORT PIN P1.1 IS SET AS OUTPUT PIN
            //P2OUT = 0x0a;  // LED connected to the port pin p2.1 indicating switch status is kept on. and led connected to p2.3 indicating time delay of 1 sec. is kept on.  
            // x=x++;
     // }while(1);
// Wait for overflow
} // doing nothing
     
     
   
     
}  while (TACTL_bit.TAIFG == 0);
 // Back around infinite loop

P2DIR=   0X0a;  // PORT PIN P1.1 IS SET AS OUTPUT PIN
P2OUT = 0x02;  // LED connected to the port pin p2.1 indicating switch status is kept on. and led connected to p2.3 indicating time delay of 1 sec. is kept on.  
   //   P2OUT =(((LED1)|(LED2))^P2OUT); // Toggle LEDs    /switch off the led as the 1sec. of time is over.
   // x= (x/2);

do{
}while(1);

}






void main (void)
{
 
    // P1OUT = 0x02; // only timer led is on and the led for switch is off.
     //                   P1DIR=   0X02;  // PORT PIN P1.1 IS SET AS OUTPUT PIN
        WDTCTL = WDTPW|WDTHOLD; // Stop watchdog timer
      x=0;
      w=0;
  // do
      for (w=0; w<1; w++)
      {   
      delay_1_sec();
      }//while();
}
---------------------------------------------------------------------------------------------------------------- 

//

//explaination---

In above code, I am polling port pin P2.1 to a switch/ function generator.

and P2.3 to a LED that will glow till the timer of 1 sec. is running. 

hope u will get some more info from above code. thanks once again..