fet140_sd16_grpchcontconv_isr.c

msp430f14x 系列片内外设的实例代码

//******************************************************************************
//  MSP-FET430P140 Demo - SD16, Continous Conversion on Group of Channels
// 
//  This example shows how to perform a continous conversion on a Group 
//  of channels using ISR. It performs continous conversions on channels 0,1 & 2.
//  The conversion results are stored in SD16MEM0, MEM1 & MEM2. Test by 
//  applying a voltage to channels, then setting and running to a break point at the 
//  mentioned instruction. To view the conversion results, open watch
//  window in C-Spy and view the contents of "Ch0results", "Ch1results", and 
//  "Ch2results" after running to the breakpoint.
//
//               MSP430FE427
//             ---------------
//            |               |
//            |           I1+ |<---- Vin 1+
//            |           I1- |<---- Vin 1-
//            |           I2+ |<---- Vin 2+
//            |           I2- |<---- Vin 2-
//            |           V1+ |<---- Vin 3+
//            |           V1- |<---- Vin 3-
//            |               |
//
//
//  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 Ch0results[Num_of_Results];  // These need to be global in 
static unsigned int Ch1results[Num_of_Results];  // this example. Otherwise, the 
static unsigned int Ch2results[Num_of_Results];  // compiler removes them because
                                                 // they are not used

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
  SD16CCTL0 |= SD16GRP;                // Enable Grouping with next higher channel
  SD16CCTL1 |= SD16GRP;                // Enable Grouping with next higher channel
  SD16CCTL2 |= SD16IE;                 // Enable Interrupts
  _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;
  
  Ch0results[index] = SD16MEM0;        // Move Ch0 results, IFG is cleared
  Ch1results[index] = SD16MEM1;        // Move Ch1 results, IFG is cleared
  Ch2results[index] = SD16MEM2;        // Move Ch2 results, IFG is cleared    

  index++;                             // Increment results index
  if (index == 8)
  {
    index = 0;                         // SET BREAKPOINT HERE
                                       
  }

}