fet140_sd16_singchcontconv.c

msp430f14x 系列片内外设的实例代码

//******************************************************************************
//  MSP-FET430P140 Demo - SD16, Continous Conversion on Single Channel
// 
//  This example shows how to perform a Multiple continous SD16 conversion on a 
//  single channel. It uses internal reference and performs a multiple conversions 
//  on channel 2. Each conversion result is moved to an 8-element array called 
//  results[].
//  Test by applying a voltage to channel 2, then running. To view the conversion 
//  results, open a watch window and view 'results' after running to the break 
//  point
//
//               MSP430FE427
//             ---------------
//            |               |
//            |           V1+ |<---- Vin +
//            |           V1- |<---- Vin -
//            |               |
//
//
//  Harman Grewal
//  Texas Instruments, Inc
//  Oct, 2004
//  IAR Embedded Workbench Version: 2.21B
//******************************************************************************

#include          "msp430xE42x.h"             // Standard Equations

#define   Num_of_Results   8

static unsigned int results[Num_of_Results];  // Needs to be global in this
                                              // example. Otherwise, the
                                              // compiler removes it because it 
                                              // is not used for anything.

void main(void)
{ 
  volatile unsigned int i;
  
  WDTCTL = WDTPW+WDTHOLD;                     // Stop watchdog timer
  FLL_CTL0 |= XCAP14PF;                       // Set load capacitance for xtal.
  for (i = 0; i < 20000; i++);                // Delay - to allow watch crystal to stabilize.
  SD16CTL = SD16REFON+SD16SSEL0;              // Turn on SD16 Ref,SMCLK
  SD16CCTL2 |= SD16IE ;                       // Interrupt Enable for Ch2
  SD16INCTL2 |= SD16INTDLY0;                  // First Interrupt on 3rd Sample
  _EINT();                                    // Enable interrupts
  for ( i=0; i<0x3600; i++)                   // Delay for reference start-up
  {
  }                
  
  SD16CCTL2 |= SD16SC;                        // Start conversion
  _BIS_SR(LPM0_bits);                         // Enter LPM0

}  
#pragma vector=SD16_VECTOR
__interrupt void SD16ISR (void)
{
  static unsigned int index = 0;
   
  results[index] = SD16MEM2;                  // Move results
  index++;                                    // Increment results index
  if (index == 8)
  {
    index = 0;                                // SET BREAKPOINT HERE
  }  
}