MSP430F1612, RS232 communication

Did you check source code examples? Which part you did not understand?

Nicolae Miron said:

Can anybody help me?

To help you, you need to show us the part of the code which; initialize, sent/receive and the ISR for the USART.

Nicolae Miron said:

For receiving characters from PC using also idle-line mode

If you just want to receive what's on the line, don't use idle line multiprocessor mode.

Thanks everybody for trying to help me. For better understanding, you have the code below:

#include <io430x16x.h>
#include <intrinsics.h>

void main(void)
{
  //Stop WDT
  WDTCTL = WDTPW + WDTHOLD + WDTTMSEL; 
 //dis GIE
  __bic_SR_register(GIE);
 
  // 9600 baud; 
  unsigned char u0br_1 = 0x00;
  unsigned char u0br_0 = 0x6D;
  unsigned char u0_mctl = 0x03;
  //store RsDat in  RAM starting at 0x2480
  unsigned short rx_ram_adr = 0x2480;
 

  // ========= for TxD only =========
  // "$"
 // unsigned char u0_txdat_1 = 0x24;
  // "1"
 // unsigned char u0_txdat_2 = 0x31;
  // "2"
 // unsigned char u0_txdat_3 = 0x32;
  // "3"
 // unsigned char u0_txdat_4 = 0x33;
  // "space"
 // unsigned char u0_txdat_idle = 0xFF;
  // array
 // unsigned char chArray[5];
 // chArray[0] = u0_txdat_1;
 // chArray[1] = u0_txdat_2;
 // chArray[2] = u0_txdat_3;
 // chArray[3] = u0_txdat_4;
 // chArray[4] = u0_txdat_idle;
   
 // int szchArray = sizeof(chArray);
 // int jarray = 1;
// ======== END of TxD initialization ============ 
 
 // Timer param.
 // counting index
 // unsigned short ix;
 // max index value
 // unsigned short maxix = 650;    
 
  //============ Set ACLK, XT2CLK ==========================
  //SELM1=1; SELM0=0 selects also DCOCLK: BUG? Check this.
  //Impossible to select MCLK from XT2CLK
  //XT2 ON
  BCSCTL1 &= ~XT2OFF;
  //LFXT1 with 32768Hz crystal, OK
  BCSCTL1 &= ~XTS;
  // ACLK /1
  BCSCTL1 &= ~DIVA1;
  BCSCTL1 &= ~DIVA1; //ACLK /1
  // XT2CLK sel
  BCSCTL2 |= SELM1;
  BCSCTL2 &= ~SELM0; //XT2CLK sel;
  // SMCLK from MCLK
  BCSCTL2 |= SELS; // SMCLK from MCLK
  // SMCLK = MCLK 1/4; USART req. 1.0486MHz~=0.95us
  BCSCTL2 |= DIVS1;
  BCSCTL2 &= ~DIVS0;
  // Internal Resistor
  BCSCTL2 &= ~DCOR;
  //================= End CLK INIT =========================
 
   //========== Init MSP430F1612 USART0 / RS232 use UTXD0, URXD0 ======================
  //Port P3.4, P3.5
 
    // P3.4 TxD
    P3SEL |= P3SEL_4;
    // P3.4 OUT
    P3DIR |= P3DIR_4;
    // P3.4 TxD
    P3OUT |= P3OUT_4;
  
    // P3.5. RxD
    P3SEL |= P3SEL_5;
    // P3.5 IN
    P3DIR &= ~P3DIR_5;
    // read RxD
    P3IN |= __READ P3IN_5;
   
     // P3.6. Error_LED
    P3SEL |= P3SEL_6;
    // P3.6 OUT
    P3DIR |= P3DIR_6;
    // OUT LED_off
    P3OUT &= ~P3OUT_6;   
 
    // P3.7. Check Rx
    P3SEL |= P3SEL_7;
    // P3.7 OUT
    P3DIR |= P3DIR_7;
    // OUT Low
    P3OUT &= ~P3OUT_7;     
   
     // P5.4 funct
    P5SEL &= ~P5SEL_4;
    // P5.4 out
    P5DIR |= P5DIR_4;
    // CS->H for testing
    P5OUT |= P5OUT_4;
   
    //Baud rate registers: SMCLK/4
    U0BR1 = u0br_1;
    U0BR0 = u0br_0;
    U0MCTL = u0_mctl;

    // U0CTL programming
    // SW reset; 8-bits
    U0CTL |= SWRST + CHAR;
    // Idle line protocol
    U0CTL &= ~MM;
    // UART mode
    U0CTL &= ~SYNC;
    // No loopback
    U0CTL &= ~LISTEN;
    // 1 Stop bit
    U0CTL &= ~SPB;
    // No parity
    U0CTL &= ~PENA;
   
    // U0TxCTL setup
    // Enable Start edge
    U0TCTL |= URXSE;
  
    // U0RCTL programming
    // Allow all addr+data
    U0RCTL |= URXWIE;
    // Reset Rx_error; just to make sure is OK
    //U0RCTL &= ~RXERR;
    // En. Int1
    IE1 |= URXIE0;


    P5OUT &= ~P5OUT_4;
    P5OUT |= P5OUT_4;
   
    // Enable Rx USART0
    ME1 |= URXE0;
     
    //IE2: UTXIE1 and URXIE1 disabled by SWRST
    //Clear SWRST for USART operation
    U0CTL &= ~SWRST;


   
    // Check char Rx  ?
    if((IFG1 & URXIFG0) == 1)
    {
       P3OUT |= P3OUT_7;
    }
  // Check if Data/Addr  Is it OK?
    if ((U0RCTL & RXWAKE) == 0)
    {
      // Store U0RXBUF to RAM
      *((unsigned int*)(rx_ram_adr)) = (__READ U0RXBUF);  
    }
    else
    {
      // Error: Rx char is addr. Activate LED
      P3OUT |= P3OUT_6;    
    }

    // Disable Rx USART0
    ME1 &= ~URXE0;
 
   
}

Thanks in advance for your answers.

Nicolae

Setup looks Ok. But you don’t have a for or while loop inside main, main will run only ones and will ends up somewhere in the sky.

You enable interrupt but there is no interrupt service routine (ISR), same will end somewhere in the sky.