#include <msp430x14x.h>

#define uint unsigned int
#define uchar unsigned char
             //P1.2接RD(第9腳)
#define MOD1_1 P1OUT |= BIT0 //P1.0接MOD1(第14腳)
#define MOD1_0 P1OUT &= ~BIT0
#define MOD2_1 P1OUT |= BIT1 //P1.1接MOD2(第15腳)
#define MOD2_0 P1OUT %= ~BIT1

void SysInit(uint x)
{
    if (x == 1)
    {
      P1DIR = 0XFF;P1OUT = 0XFF; //初始化P1
      P2DIR = 0XFF;P2OUT = 0XFF; //初始化P2
      P3DIR = 0XFF;P3OUT = 0XFF; //初始化P3
      P4DIR = 0XFF;P4OUT = 0XFF; //初始化P4
      P5DIR = 0XFF;P5OUT = 0XFF; //初始化P5
      P6DIR = 0XFF;P6OUT = 0XFF; //初始化P6
      WDTCTL = WDTPW + WDTHOLD;  //關閉看門狗
    }

}

int main( void )
{
      SysInit(1);
      MOD2_0;                 //使用模式1，即解調模式
      MOD1_1;
      P3DIR = 0x00;         //設置P1.2為輸入狀態
      P4OUT = P3IN & BIT2;

      while (1)
      {

      P4OUT = P3IN & BIT2;
      if(P4OUT == 0)    //AI輸入為2100Hz
      {
        P2OUT &= ~BIT0;
      }
      else
      {
        P2OUT &= ~BIT1;
      }

      }
}