main.c.bak

基于MSP430系列单片机的485串口通信程序。

//******************************************************************************
//   MSP430F22x4 Demo - USCI_A0, Ultra-Low Pwr UART 9600 Echo ISR, 32kHz ACLK
//
//   Description: Echo a received character, RX ISR used. Normal mode is LPM3,
//   USCI_A0 RX interrupt triggers TX Echo.
//   ACLK = BRCLK = LFXT1 = 32768Hz, MCLK = SMCLK = DCO ~1.2MHz
//   Baud rate divider with 32768Hz XTAL @9600 = 32768Hz/9600 = 3.41
//   //* An external watch crystal is required on XIN XOUT for ACLK *//
//
//                MSP430F22x4
//             -----------------
//         /|\|              XIN|-
//          | |                 | 32kHz
//          --|RST          XOUT|-
//            |                 |
//            |     P3.4/UCA0TXD|------------>
//            |                 | 9600 - 8N1
//            |     P3.5/UCA0RXD|<------------
//
//   A. Dannenberg
//   Texas Instruments Inc.
//   October 2006
//   Built with IAR Embedded Workbench Version: 3.41A
//******************************************************************************
#include  "msp430x22x2.h"
#define TI_CC_LED2_PxOUT         P4OUT
#define TI_CC_LED2_PxDIR         P4DIR
#define TI_CC_LED2              0x01

unsigned char xx;
void delay(int a,int b)
{
 for(int i=a;i>0;i--)
   for(int j=b;j>0;j--);
}

void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT

  BCSCTL1 = CALBC1_1MHZ;                    // Set DCO
  DCOCTL = CALDCO_1MHZ;
  P3SEL = 0x30;                             // P3.4,5 = USCI_A0 TXD/RXD
  P3DIR |= 0x50;                             // All P3.x outputs
  P3DIR &= ~0x20;                             // All P3.x outputs
  TI_CC_LED2_PxDIR = TI_CC_LED2 ;
  TI_CC_LED2_PxOUT |=  TI_CC_LED2;
  UCA0CTL1 |= UCSSEL_2;                   // CLK = ACLK
  UCA0CTL1 |= UCSSEL_1;                     // CLK = ACLK
  UCA0BR0 = 0x68;                           // 32kHz/9600 = 3.41
  UCA0BR1 = 0x00;                           //
  UCA0MCTL |=  UCBRS0     ;     // Modulation UCBRSx = 3UCBRS1 + UCBRS0;
  UCA0MCTL = UCBRS1 + UCBRS0; 
  UCA0CTL1 &= ~UCSWRST;                     // **Initialize USCI state machine**
  IE2 |= UCA0RXIE;
  while (!(IFG2&UCA0TXIFG));                         // Enable USCI_A0 RX interrupt
  P3OUT &=~0x40; 
  delay(100,100);
  P3OUT |=0x40;     
 _EINT(); 
  
  
  //delay(100,100);
                             //中断使能
 for (;;)
  {
    
  __bis_SR_register(LPM3_bits + GIE);         // Enter LPM3, interrupts enabled
  _NOP();                          
  }  

}
#pragma vector=USCIAB0RX_VECTOR
__interrupt void USCI0RX_ISR(void)
{ 
     P3OUT &=~0x40;
  UCA0TXBUF = UCA0RXBUF;  
  while (!(IFG2&UCA0TXIFG));  
  TI_CC_LED2_PxOUT |=  TI_CC_LED2;
   delay(100,100);
   delay(100,100);
   TI_CC_LED2_PxOUT &=  ~TI_CC_LED2;
   delay(100,100);
   delay(100,100);
  P3OUT |=0x40;
}