fet140_spi0_slav0.c

430单片机的基本例程。都已经调通可以使用。是新手上路必备

//******************************************************************************
//  MSP-FET430P140 Demo - USART0 SPI full-Duplex 3-wire Slave P1.x Exchange
//
//  Description: SPI Master communicates at fast as possible, full-duplex with 
//  SPI Slave using 3-wire mode. The level on P1.4/5 is TX'ed and RX'ed to P1.0
//  and P1.1. Master will pulse slave Reset on init to insure synch start.  
//  Slave normal mode is LPM4.  
//  ACLK = n/a, MCLK = SMCLK = DCO ~ 800kHz, ULCK = external
//
//             fet140_slav0               fet140_mstr0
//             MSP430F169 Slave           MSP430F169 Master
//             -----------------          -----------------
//            |              XIN|-    /|\|              XIN|-
//            |                 |      | |                 |
//            |             XOUT|-     --|RST          XOUT|-
//            |                 | /|\    |                 |
//            |              RST|--+<----|P3.0             |
//      LED <-|P1.0             |        |             P1.4|<- 
//      LED <-|P1.1             |        |             P1.5|<- 
//          ->|P1.4             |        |             P1.0|-> LED
//          ->|P1.5             |        |             P1.1|-> LED
//            |       SIMO0/P3.1|<-------|P3.1             |     
//            |       SOMI0/P3.2|------->|P3.2             |   
//            |        UCLK/P3.3|<-------|P3.3             | 
//
//  M. Buccini
//  Texas Instruments, Inc
//  February 2004
//  Updated for IAR Embedded Workbench Version: 2.21B
//******************************************************************************

#include  <msp430x14x.h>

void main(void)
{

  WDTCTL = WDTPW + WDTHOLD;                 // Stop watchdog
  P1OUT = 0x00;                             // P1.0 setup for LED output
  P1DIR |= 0x03;  
  P3SEL |= 0x0E;                            // P3.1,2,3 SPI option select
  U0CTL = CHAR + SYNC + SWRST;              // 8-bit, SPI
  U0TCTL = CKPL + STC;                      // Polarity, 3-wire
  U0BR0 = 0x02;                             // SPICLK = SMCLK/2
  U0BR1 = 0x00; 
  U0MCTL = 0x00; 
  ME1 |= USPIE0;                            // Module enable
  U0CTL &= ~SWRST;                          // SPI enable
  IE1 |= URXIE0 + UTXIE0;                   // RX and TX interrupt enable

  _BIS_SR(LPM4_bits + GIE);                 // Enter LPM4 w/ interrupt
}

#pragma vector=USART0RX_VECTOR
__interrupt void SPI0_rx (void)
{
  P1OUT = RXBUF0;                           // RXBUF0 to TXBUF0
}
                  
#pragma vector=USART0TX_VECTOR
__interrupt void SPI0_tx (void)
{
  unsigned int i;

  i = P1IN;            
  i = i >> 4;
  TXBUF0 = i;                               // Transmit character
}