【MSP430】进入LPM3模式后，仍可以产生TB0时钟中断？

探索者W · 发表于 2019-12-16 17:13:37

      使用MSP430FR2153芯片，设置TB0时钟来源为SMCLK，程序在进入LPM3后，还是产生了TIMERB0_ISR中断。
      按芯片手册上说明的进入LPM3后，CPU、MCLK、SMCLK关闭。调试时，相关的标志位SCG1=1、SCG0=1、CPUOFF=1、GIE=1。

进入LPM3时SR状态

等待一段时间后，进入了中断。

LPM3模式下进入中断

   SMCLK已经关闭，为什么还是产生了TIMERB0_ISR中断？

   以下为程序全部内容：
#include <msp430.h>

int main(void)
{
WDTCTL = WDTPW | WDTTMSEL | WDTCNTCL | WDTIS2 | WDTSSEL__ACLK;// WDT ~3s, ACLK, interval timer

SFRIE1 |= WDTIE;                                           // Enable WDT interrupt

CSCTL4 = SELMS__DCOCLKDIV | SELA__VLOCLK;                   // MCLK=SMCLK=DCO; ACLK=VLO

// Port Configuration all pins to output low
P1OUT = 0x00; P2OUT = 0x00;
P3OUT = 0x00; P4OUT = 0x00;
P5OUT = 0x00; P6OUT = 0x00;
P1DIR = 0xff; P2DIR = 0xff;
P3DIR = 0xff; P4DIR = 0xff;
P5DIR = 0xff; P6DIR = 0xff;

P1SEL1 |= BIT1;                                              // Output ACLK through P1.1

//定时器 TB0 配置
TB0CCTL0 |= CCIE;                            // TBCCR0 interrupt enabled
TB0CCR0 = 50000;
TB0CTL = TBSSEL__SMCLK | MC__UP;          // SMCLK, UP mode

// Disable the GPIO power-on default high-impedance mode
// to activate previously configured port settings
PM5CTL0 &= ~LOCKLPM5;

__bis_SR_register(LPM3_bits | GIE);                         // Enter LPM3
__no_operation();                                           // For debug
}

// Watchdog Timer interrupt service routine
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=WDT_VECTOR
__interrupt void WDT_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(WDT_VECTOR))) WDT_ISR (void)
#else
#error Compiler not supported!
#endif
{
P1OUT ^= BIT0;                                              // Toggle P1.0 (LED) every 3s
}
// Timer0_B0 interrupt service routine
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector = TIMER0_B0_VECTOR
__interrupt void Timer0_B0_ISR (void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(TIMER0_B0_VECTOR))) Timer0_B0_ISR (void)
#else
#error Compiler not supported!
#endif
{
  P1OUT ^= BIT0;
}