MSP430G2553,I/O動作異常

我使用MSP430G2553 LaunchPad

將P2.3作為輸出，無論程序怎麼改變，P2.3都需要保持high。

但P2.3會在中斷程序發生時，瞬間變成low，不知道是不是設置有誤?

程序如下：

#include"msp430g2553.h"

#define PERIOD 200

#define naturalF 118800

int flag_IE=1;

int count=2;

void delayus(int us)

{

int i;

for(i=0;i<us;i++)

{

   __delay_cycles(1);

}

}

void main(void)

{

   WDTCTL=WDTPW+WDTHOLD;

   DCOCTL|=DCO1+DCO0;

   BCSCTL1|=RSEL3;

   CACTL1 =CAON+ CAREF_0+CAIE + CAIES;

   CACTL2 = P2CA1 + P2CA0 + CAF;    

     P1DIR |= BIT0+BIT1+BIT4+BIT5+BIT6+BIT7;

     P1SEL2= 0;

     P1SEL = 0;

     P1REN=0;

      P2DIR |= BIT5+BIT1+BIT2+BIT3+BIT4+BIT7;

     P2SEL = 0;

     P2SEL2= 0;

     P2REN=0;

     P1OUT&=~BIT4+BIT5+BIT6+BIT7;

     P2OUT&=~BIT2+BIT4;

     P2OUT|=BIT5+BIT1+BIT3;

     __enable_interrupt();

}

#pragma vector=COMPARATORA_VECTOR

__interrupt void comp(void)

{

   //P1IE=0;

   CACTL1 &=~ CAIE;

   P2OUT|=BIT5+BIT3;

               if(flag_IE==1)

               {

                 P1OUT&=~BIT5+BIT6;

                 P2OUT&=~BIT1+BIT2;

                 P1OUT|=BIT4+BIT7;

                P2OUT|=BIT5+BIT4+BIT3;

                 delayus(26); //9.947us

                 //P2OUT|=BIT3+BIT7;

                 P2OUT&=~BIT1;

                 P2OUT|=BIT5+BIT2+BIT3;

                 P1OUT&=~BIT3+BIT4+BIT5+BIT6+BIT7;

                 delayus(22);

                 // P2OUT|=BIT3+BIT7;

                 P1OUT&=~BIT4+BIT7;

                 P1OUT|=BIT5+BIT6;

                 P2OUT&=~BIT1+BIT2;

                 P2OUT|=BIT5+BIT3;

                 delayus(26);

                 //P2OUT|=BIT3+BIT7;

                 P1OUT&=~BIT3+BIT4+BIT5+BIT6+BIT7;

                 P2OUT|=BIT5+BIT1+BIT3;

                 P2OUT&=~BIT2+BIT4;

                 flag_IE=0;

                 CACTL1 &=~ CAIES;

               }

              else          

               {

                 P1OUT&=~BIT4+BIT7;

                 P1OUT|=BIT5+BIT6;

                 P2OUT&=~BIT1+BIT2;

                 P2OUT|=BIT5+BIT3+BIT4;

                 delayus(26);

                 P2OUT&=~BIT1;

                 P2OUT|=BIT5+BIT2+BIT3+BIT4;

                 P1OUT&=~BIT3+BIT4+BIT5+BIT6+BIT7;

                 delayus(22);

                 P1OUT&=~BIT5+BIT6;

                 P2OUT&=~BIT1+BIT2;

                 P1OUT|=BIT4+BIT7;

                  P2OUT|=BIT5+BIT3+BIT4;

                 delayus(26);

                 P1OUT&=~BIT3+BIT4+BIT5+BIT6+BIT7;

                 P2OUT|=BIT5+BIT3+BIT1+BIT4;

                 P2OUT&=~BIT2+BIT4;

                 flag_IE=1;

                 CACTL1 |= CAIES;

                 // P1IES|=BIT0;                

               }

   CACTL1|= CAIE;

     CACTL1 &=~ CAIFG;

}

黃色為輸入訊號(介於P1.0 & P1.1)

藍色為P2.3的輸出訊號

放大之後如下：

  我該怎麼調整呢?

灰小子：

程序里没看出p2.3有什么问题。你的外部电路是怎么样的？

xyz549040622：

P2.3的输出没问题，你中断中的逻辑的问题，仔细整理逻辑吧。

Susan Yang：

请把 Launchpad上J3 的 RXD TXD 跳帽拔掉再测量，它们使用的是P1.1 和 P1.2

gaoyang9992006：

一步一步的调试，看看是走到哪一行代码出行了这个低脉冲。