[求助] msp430运用定时器A和比较器A测电阻。不知道问题出在哪里

#include "msp430x14x.h"
#define REF_O (P1DIR |= BIT3)
#define MEA_O (P1DIR |= BIT4)
#define REF_I (P1DIR |= BIT3)
#define MEA_I (P1DIR |= BIT4)
#define REF_H (P1OUT |= BIT3)
#define REF_L (P1OUT &= ~BIT3)
#define MEA_H (P1OUT |= BIT4)
#define MEA_L (P1OUT &= ~BIT4)
#define REF (P1OUT & BIT3)
#define MEA (P1OUT & BIT4)
#define Ref (2000)
unsigned char overflow=0,ref_flag=0,mea_flag=0;
unsigned long int t_ref=0,t_mea=0;

void delay_1s()
{
  unsigned int x;
  unsigned int y;
  for(x=1000;x>0;x--)
    for(y=8000;y>0;y--);
}

void campare_init()
{
  P2SEL |= BIT3;
  P2DIR &= ~BIT3;
  TACTL |= TASSEL_2+ID_3+TAIE+TACLR;
  CACTL1 |= CAREF_1+CAON+CAIE+CARSEL+CAIES;
  CACTL2 |= P2CA0+CAF;  
}

void campare_proceed()
{
    P2SEL |= BIT3;
    P2DIR &= ~BIT3;
    REF_O;
    MEA_O;
    REF_H;
    MEA_L;
    MEA_I;
    delay_1s();
    REF_L;
    TACTL |= MC_2;
    while(!ref_flag);
    REF_L;
    REF_I;
    MEA_O;
    MEA_H;
    delay_1s();
    MEA_L;
    while(!mea_flag);   
}


unsigned int campare_calculate()
{
  return t_mea*Ref/t_ref;
}


#include "msp430x14x.h"
#include "clk_init.h"
#include "clk_init.c"
#include "campare.h"
#include "campare.c"
#include "LCD1602.h"
#include "LCD1602.c"
#include "stdio.h"

int main( void )
{
  unsigned int r_mea=0;
  char p[7];
  // Stop watchdog timer to prevent time out reset
  WDTCTL = WDTPW + WDTHOLD;
  clk_init();
  lcd_init();
  campare_init();
  lcd_display_location(1,1);
  lcd_write_string("Wait...");
  campare_proceed();
  r_mea=campare_calculate();
  sprintf(p,"%u",r_mea);
  lcd_write_string(p);
  while(1)
  {
  }
  return 0;
}

#pragma vector=TIMERA1_VECTOR
__interrupt void timer()
{
  overflow++;
  TACTL &= ~TAIFG;
}

#pragma vector=COMPARATORA_VECTOR
__interrupt void campare_a()
{
  if(REF)
  {
    t_ref=TAR+overflow*0xffff;
    ref_flag=1;
    overflow=0;
  }
  if(MEA)
  {
    t_mea=TAR+overflow*0xffff;
    mea_flag=1;
  }
}