MSP430FR5728: 无法达到低功耗的效果

#include <msp430.h>

int main(void)
{
  WDTCTL = WDTPW + WDTHOLD;
  P1DIR = 0; 
  P1OUT = 0; 
  P1REN = 0xFF;
  
  P2DIR = 0; 
  P2OUT = 0; 
  P2REN = 0xFF;
    
  PJDIR = 0xFF;
  PJOUT = 0;
  
  // XT1 Setup 
    
  CSCTL0_H = 0xA5;
  CSCTL1 |= DCOFSEL0 + DCOFSEL1;             // Set max. DCO setting
  CSCTL2 = SELA_3 + SELS_3 + SELM_3;        // set ACLK = XT1; MCLK = DCO
  CSCTL3 = DIVA_1 + DIVS_1 + DIVM_1;        // set all dividers 
  
  // Turn off Temp sensor
  REFCTL0 |= REFTCOFF; 
  REFCTL0 &= ~REFON;
  ADC10CTL0 &= ~ADC10ON;

  // Turn on LED 
  P1DIR |= BIT0;
  __bis_SR_register(LPM1_bits+GIE);
  
}