//

//

// MSP430G2xx3

// -----------------

// /|\| XIN|-

// | | |

// --|RST XOUT|-

// | |

// | CCI0B/TXD/P1.1|-------->

// | | 9600 8N1

// | CCI0A/RXD/P1.2|<--------

// Built with IAR Embedded Workbench Version: 5.40

//串口调试助手，下载地址：http://www.sudt.com/download/AccessPort137.zip

//******************************************************************************

#include "msp430g2553.h"

//------------------------------------------------------------------------------

// Hardware-related definitions

//------------------------------------------------------------------------------

#define UART_TXD 0x02 // TXD on P1.1 (Timer0_A.OUT0)

#define UART_RXD 0x04 // RXD on P1.2 (Timer0_A.CCI1A)

//------------------------------------------------------------------------------

// Conditions for 9600 Baud SW UART, SMCLK = 1MHz，设置波特率，仅仅修改下面一下数据即可，如9600，2400

//9600，2400工作稳定。波特率不宜太高。

//------------------------------------------------------------------------------

#define UART_TBIT_DIV_2 (1000000 / (9600 * 2))

#define UART_TBIT (1000000 / 9600)

//------------------------------------------------------------------------------

// Global variables used for full-duplex UART communication

//------------------------------------------------------------------------------

unsigned int txData; // UART internal variable for TX

unsigned char rxBuffer; // Received UART character

//------------------------------------------------------------------------------

// Function prototypes

//------------------------------------------------------------------------------

void TimerA_UART_init(void);

void TimerA_UART_tx(unsigned char byte);

void TimerA_UART_print(char *string);

//------------------------------------------------------------------------------

// main()

//------------------------------------------------------------------------------

void main(void)

{

WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer

DCOCTL = 0x00; // Set DCOCLK to 1MHz

BCSCTL1 = CALBC1_1MHZ;

DCOCTL = CALDCO_1MHZ;

P1OUT = 0x00; // Initialize all GPIO

P1SEL = UART_TXD + UART_RXD; // Timer function for TXD/RXD pins

P1DIR = 0xFF & ~UART_RXD; // Set all pins but RXD to output

P2OUT = 0x00;

P2SEL = 0x00;

P2DIR = 0xFF;

__enable_interrupt();

TimerA_UART_init(); // Start Timer_A UART

TimerA_UART_print("G2553 TimerA UART\r\n");

TimerA_UART_print("READY.Echo Input，and Monitor.\r\n");

for (;;)

{

// Wait for incoming character

__bis_SR_register(LPM0_bits);

// Update board outputs according to received byte，根据接收到的数据点亮发光管

//建议16进制，例如01H P1.0亮 11H P1.0 1.6亮

if (rxBuffer & 0x01) P1OUT |= 0x01; else P1OUT &= ~0x01; // P1.0

if (rxBuffer & 0x02) P1OUT |= 0x08; else P1OUT &= ~0x08; // P1.3

if (rxBuffer & 0x04) P1OUT |= 0x10; else P1OUT &= ~0x10; // P1.4

if (rxBuffer & 0x08) P1OUT |= 0x20; else P1OUT &= ~0x20; // P1.5

if (rxBuffer & 0x10) P1OUT |= 0x40; else P1OUT &= ~0x40; // P1.6

if (rxBuffer & 0x20) P1OUT |= 0x80; else P1OUT &= ~0x80; // P1.7

if (rxBuffer & 0x40) P2OUT |= 0x40; else P2OUT &= ~0x40; // P2.6

if (rxBuffer & 0x80) P2OUT |= 0x80; else P2OUT &= ~0x80; // P2.7

// Echo received character，回传发送的数据

TimerA_UART_tx(rxBuffer); //

}

}

//------------------------------------------------------------------------------

// Function configures Timer_A for full-duplex UART operation

//------------------------------------------------------------------------------

void TimerA_UART_init(void)

{

TACCTL0 = OUT; // Set TXD Idle as Mark = '1'

TACCTL1 = SCS + CM1 + CAP + CCIE; // Sync, Neg Edge, Capture, Int

TACTL = TASSEL_2 + MC_2; // SMCLK, start in continuous mode

}

//------------------------------------------------------------------------------

// Outputs one byte using the Timer_A UART

//------------------------------------------------------------------------------

void TimerA_UART_tx(unsigned char byte)

{

while (TACCTL0 & CCIE); // Ensure last char got TX'd

TACCR0 = TAR; // Current state of TA counter

TACCR0 += UART_TBIT; // One bit time till first bit

TACCTL0 = OUTMOD0 + CCIE; // Set TXD on EQU0, Int

txData = byte; // Load global variable，要发送的数据

txData |= 0x100; // Add mark stop bit to TXData

txData <<= 1; // Add space start bit

}

//------------------------------------------------------------------------------

// Prints a string over using the Timer_A UART

//------------------------------------------------------------------------------

void TimerA_UART_print(char *string)

{

while (*string) {

TimerA_UART_tx(*string++);

}

}

//------------------------------------------------------------------------------

// Timer_A UART - Transmit Interrupt Handler

//------------------------------------------------------------------------------

#pragma vector = TIMER0_A0_VECTOR

__interrupt void Timer_A0_ISR(void)

{

static unsigned char txBitCnt = 10;

TACCR0 += UART_TBIT; // Add Offset to CCRx

if (txBitCnt == 0) { // All bits TXed?

TACCTL0 &= ~CCIE; // All bits TXed, disable interrupt

txBitCnt = 10; // Re-load bit counter

}

else {

if (txData & 0x01) {

TACCTL0 &= ~OUTMOD2; // TX Mark '1'

}

else {

TACCTL0 |= OUTMOD2; // TX Space '0'

}

txData >>= 1;

txBitCnt--;

}

}

//------------------------------------------------------------------------------

// Timer_A UART - Receive Interrupt Handler

//------------------------------------------------------------------------------

#pragma vector = TIMER0_A1_VECTOR

__interrupt void Timer_A1_ISR(void)

{

static unsigned char rxBitCnt = 8;

static unsigned char rxData = 0;

switch (__even_in_range(TA0IV, TA0IV_TAIFG)) { // Use calculated branching

case TA0IV_TACCR1: // TACCR1 CCIFG - UART RX

TACCR1 += UART_TBIT; // Add Offset to CCRx

if (TACCTL1 & CAP) { // Capture mode = start bit edge

TACCTL1 &= ~CAP; // Switch capture to compare mode

TACCR1 += UART_TBIT_DIV_2; // Point CCRx to middle of D0

}

else {

rxData >>= 1;

if (TACCTL1 & SCCI) { // Get bit waiting in receive latch

rxData |= 0x80;

}

rxBitCnt--;

if (rxBitCnt == 0) { // All bits RXed?

rxBuffer = rxData; // Store in global variable

rxBitCnt = 8; // Re-load bit counter

TACCTL1 |= CAP; // Switch compare to capture mode

__bic_SR_register_on_exit(LPM0_bits); // Clear LPM0 bits from 0(SR)

}

}

break;

}

}