//
//MSP430G2xx3
//-----------------
///||XIN|-
//| ||
//--|RSTXOUT|-
//||
//|CCI0B/TXD/P1.1|-------->
//|| 9600 8N1
//|CCI0A/RXD/P1.2|<--------
// Built withIAR Embedded Workbench Version: 5.40

//串口調(diào)試助手，下載地址：http://www.sudt.com/download/AccessPort137.zip
//******************************************************************************

#include "msp430g2553.h"

//------------------------------------------------------------------------------
// Hardware-related definitions
//------------------------------------------------------------------------------
#define UART_TXD0x02// TXD on P1.1 (Timer0_A.OUT0)
#define UART_RXD0x04// RXD on P1.2 (Timer0_A.CCI1A)

//------------------------------------------------------------------------------
// Conditions for 9600 Baud SW UART, SMCLK = 1MHz，設(shè)置波特率，僅僅修改下面一下數(shù)據(jù)即可，如9600，2400
//9600，2400工作穩(wěn)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");
TimerA_UART_print("READY.Echo Input，and Monitor.");

for (;;)
{
// Wait for incoming character
__bis_SR_register(LPM0_bits);

// Update board outputs according to received byte，根據(jù)接收到的數(shù)據(jù)點(diǎn)亮發(fā)光管
//建議16進(jìn)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，回傳發(fā)送的數(shù)據(jù)
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 TXd
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，要發(fā)送的數(shù)據(jù)
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;
}
}