//******************************************************************************
//  MSP-Test44x Demo - USART0 UART 2400 Ultra-low Power Echo ISR, 32kHz ACLK
//  SEND DAT  FOREXAMPLE 01 02 03 04 05 06 07 08
//  Description; Echo a received character, RX ISR used. In the Mainloop UART0
//  is made ready to receive one character with interrupt active. The Mainloop
//  waits in LPM3. The UART0 ISR forces the Mainloop to exit LPM3 after 
//  receiving eight character which echo's back the received character.
//  lcd is used to show the character receverd .
//  ACLK = UCLK0 = LFXT1 = 32768, MCLK = SMCLK = DCO ~ 800k  
//  Baud rate divider with 32768hz XTAL @2400 = 32768Hz/2400 = 13.65 (000Dh)
//  //*An external watch crystal is required on XIN XOUT for ACLK*//	  
//              
//                MSP430F449
//             -----------------
//         /|\|              XIN|-  
//          | |                 | 32768Hz  
//          --|RST          XOUT|-
//            |                 |
//            |             P2.4|-----------> 
//            |                 | 2400 - 8N1
//            |             P2.5|<-----------
//
//       
//  Lierda, Inc
//  February 2006.03
//  Built with IAR Embedded Workbench Version: 1.26B
//  ID：  MSP430-TEST44X
//  DATA：2005-7-12
//  REV： 2.0A
//  硬件連接如下：
//  1、PC機串口連接TEST44X學習板的9芯串行接口 J5_232
//  2、對撥動開關P_232、P1、U_USART，只有撥動開關 U_USART 的P2腳和P5腳撥到ON 的位置；
//     
//******************************************************************************
#include <msp430x44x.h>
static unsigned char RXTXBUFF[8];             //recever (send)data buffer
const unsigned char digit[16] = {
0x7B,  /* "0" */
0x12,  /* "1" */
0x4F,  /* "2" */
0x1F,  /* "3" */                              //0-F display table
0x36,  /* "4" */
0x3D,  /* "5" */
0x7D,  /* "6" */
0x13,  /* "7" */
0x7F,  /* "8" */
0x3F,  /* "9" */
0x77,  /* "A" */
0x7C,  /* "B" */
0x69,  /* "c" */
0x5E,  /* "D" */
0x6D,  /* "E" */
0x65,  /* "F" */
};

//-------------------------------------------------------
//------------mian ------------------------------------
//-------------------------------------------------------
void main(void)
{
  int i;    
  WDTCTL = WDTPW + WDTHOLD;              // Stop WDT
  FLL_CTL0 |= XCAP14PF;                  // Configure load caps
  UTCTL0 = SSEL0;                        // UCLK = ACLK
  UBR00 = 0x0d;                          // 32k/2400 - 13.65
  UBR10 = 0x00;                        
  UMCTL0 = 0x6B;                         // Modulation
  UCTL0 = CHAR+PENA+PEV;                 // 8-bit character *SWRST* AND EVEN BIT
  //UCTL0 = CHAR;                        // no EVEN OR ODD BIT
  ME1 |= UTXE0 + URXE0;                  // Enable USART0 TXD/RXD
  IE1 |= URXIE0;                         // Enable USART0 RX interrupt
  P2SEL |= 0x30;                         // P2.4,5 = USART0 TXD/RXD
  P2DIR |= 0x10;                         // P2.4 output direction
  LCDCTL = LCDON + LCD4MUX + LCDP2;      // STK LCD 4Mux, S0-S17
  BTCTL = BTFRFQ1;                       // STK LCD freq 
  P5SEL = 0xFC;                          // Common and Rxx all selected       
  for (i=0; i<7; ++i)                    // Display "6543210" 
  LCDMEM[i] = digit[i];                  // Test display is ok?
  LCDMEM[7]=0x0D;
  i=0;
  _EINT();                               // Enable interrupts
  
// Mainloop
  for (;;)                             
  {
   _BIS_SR(LPM3_bits);                   // Wait in LPM3 until character RXed
   _NOP();
     for (i=0;i<=7;i++)
    {
     while ((IFG1 & UTXIFG0) == 0);      // USART0 TX buffer ready?
     TXBUF0 = RXTXBUFF[i];                      // RXBUF0 to TXBUF0
     }
  }
}

// UART0 RX ISR will for exit from LPM3 in Mainloop
interrupt[UART0RX_VECTOR] void usart0_rx (void)
{                                        //i=rxtxbuff num,j=lcd display bit num,k=recever data num 
    static int i,j,k;     
    RXTXBUFF[i]=RXBUF0;                  // RXBUF0 TO BUFF
    LCDMEM[j]=digit[RXTXBUFF[i]&0x0F];   // display the date of recever      
    LCDMEM[j+1]=digit[RXTXBUFF[i]>>4];
    LCDMEM[6]=digit[k];                  // display 0---f
    LCDMEM[7]=0x00;                      // lcd high bit clear 0 
    j=j>=4?0:j+2;                                
    k=k<0xF?k+1:0;                       
    i++;
   if (i>=8)                             // recever data =8 ?                
    {i=0;                                // =8 ,send the data to cmputer
     _BIC_SR_IRQ(LPM3_bits);             

     }    // Clear LPM3 bits from 0(SR)
}