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5438 Not recognizing interrupts on UART A3.

Gerry Tucker
Prodigy 50 points

I am at my wits end!!

I think I have everything set correctly, yet when I send characters from a SI Labs CP2104-EK (USB to Serial converter)  to my 5438 no interrupt is generated. I am using RealTerm for sending from the PC, so I can vary the baud rate and how the data gets sent.

This is what I send from the USB converter.

This is what I get back from the 5438, yet there is no interrupt.

Here is what I have in code.

Initialize

 void UART3_Init (void) @ "CODE"
 {
  WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT

  UCA3CTL1 |= UCSWRST;                      // **Put state machine in reset**
  UCA3CTL1 |= UCSSEL_1;                     // ACLK
  UCA3BR0 = 0x09;   ;                       // =  1.125MHz 115200 (see User's Guide)
  UCA3BR1 = 0x00;                            // 1MHz 115200
  UCA3MCTL |= UCBRS_6 + UCBRF_0;            // Modulation
  UCA3CTL1 &= ~UCSWRST;                     // **Initialize USCI state machine**
  UCA3IE |= UCRXIE;                // Enable USCI_A3 RX interrupt
 
  __bis_SR_register(GIE);       // interrupts enabled
__delay_cycles(10000);
 }

ISR.c

#pragma location = "CODE"   
#pragma vector=USCI_A3_VECTOR
__interrupt void USCI_A3_ISR(void)
{
  switch(__even_in_range(UCA3IV,4))
  {
    char temp;
    
    case 0:
    break;                             // Vector 0 - no interrupt
    case 2:                                   // Vector 2 - RXIFG
   //char temp;
    temp = UCA3RXBUF;

some code is executed in the ISR but the ISR never gets called.


   case 4:                                 // Vector 4 - TXIFG
      __delay_cycles(5000);//(5000);                // Add small gap between TX'ed bytes
     UCA3TXBUF = TXmsg[pmsg++];
     if(nmsg==pmsg) UCA3IE &= ~UCTXIE;                    // disable USCI_A0 TX buffer

      break;
      
    default:
    break;
  }


Using IAR in debug mode I put a halt at the switch(__even_in_range(UCA3IV,4)) but no interrupt is generated.

The code is identical to the A0 UART and that works fine!

Thanks in advance for your help.

  • 0
    Guru 301540 points

    Check the error flags in the status register.

    Where is the code that initializes the pins?

  • 0 in reply to Clemens Ladisch
    Prodigy 50 points
    initialize the pins P10.4 TX P10.5 RX
    #define SetPort10 { P10SEL = 0xf0; P10OUT = 0x00; P10DIR = 0x0A; P10REN = 0x00;}

    USCI_A3 register after sending data to the 430.

    UCA3CTLW0 = 0x0040
    UCA3CTL0 = 0x00
    UCA3CTL1 = 0x40 UCSSEL0 = 1
    UCA3BRW = 0x009
    UCA3BR0 = 0x09
    UCA3BR1= 0x00
    UCA3MCTL = 0x0C UCBRS1=1, UCBRS2=1
    UCA3STAT = 0x00
    UCA3RXBUFF = 0x00
    UCA3TXBUFF = 0x00
    UCA3ABCTL = 0x00
    UCA3IRCTL = 0x0000
    UCA3IRTCTL = 0x00
    UCA3IRRTCTL = 0x00
    UCA3ICTL = 0x201
    UCA3IE = 0x01 UCRXIE=1
    UCA3IFG = 0x02 UCTXIFG =1
    UCA3IV = 0x00

    Thanks for looking at this for me.
  • 0
    Guru 74080 points
    Gerry, could you please upload the complete code?
  • 0 in reply to Dennis Eichmann
    Prodigy 50 points

    Dennis,

    Thanks for taking a look.

    I have been using UART0 for a long time with great results. I am now trying to get UART3 going so I have an additional port to talk to the outside world.

    the A0 port is going through a CP2110 located on my board to interface to the USB.

    Port A3 is supposed to go through a CP2104 external to my board.

    I have jumpered P3.5 (A0_URX) to P10.5 (A3_URX)on my board. I did this to use the same data that is coming in through my 2110 and use it to trigger the A3 interrupt.

    Initilization

      SetPort3;

    #define SetPort3  { P3SEL = 0xB6; P3OUT = 0x40; P3DIR = 0x49; P3REN = 0x00;}


      SetPort10;
    #define SetPort10  { P10SEL = 0xf0; P10OUT = 0x00; P10DIR = 0x0A; P10REN = 0x00;}
     UART0_Init();
     UART3_Init();

    /-----------------------------------------------------------------------------
    // UART0_Init
    //-----------------------------------------------------------------------------
     
     void UART0_Init (void) @ "XX25_CODE"
     {
      WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT

      UCA0CTL1 |= UCSWRST;                      // **Put state machine in reset**
      UCA0CTL1 |= UCSSEL_1;                     // ACLK
      UCA0BR0 = 0x0d;   //0x0D;                       //9 =  1MHz 115200 (see User's Guide)55 = 19200
      UCA0BR1 = 0x00;      //0;                        // 1MHz 115200
      UCA0MCTL = 0xf3;//UCA0MCTL |= UCBRS_1 + UCBRF_0;   //UCBRF_10         // Modulation UCBRSx=1, UCBRFx=0
      UCA0CTL1 &= ~UCSWRST;                     // **Initialize USCI state machine**
      UCA0IE |= UCRXIE;                // Enable USCI_A0 TX/RX interrupt
     
      __bis_SR_register(GIE);       // interrupts enabled
    __delay_cycles(10000);
     }


    void UART3_Init (void) @ "XX25_CODE"
     {
      WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT

      UCA3CTL1 |= UCSWRST;                      // **Put state machine in reset**
      UCA3CTL1 |= UCSSEL_1;                     // ACLK
     
      UCA3BR0 = 0x9;                          // =  1.125MHz 115200 (see User's Guide)
      UCA3BR1 = 0x00;                            // 1MHz 115200
     UCA3MCTL |= UCBRS_6 + UCBRF_0;            // Modulation
      UCA3CTL1 &= ~UCSWRST;                     // **Initialize USCI state machine**
      UCA3IE |= UCRXIE;                // Enable USCI_A3 RX interrupt
     
      __bis_SR_register(GIE);       // interrupts enabled
    __delay_cycles(10000);
     }

    I can step through the code during initialize and I know that UCA3 is getting initialized.

    I then start up my external GUI that is sending EE1A15C3 and expecting a response from the MSP.

    UART A0 does respond but there is no interrupt for UART A3.

    If I halt the IAR I will get  errors on UCBRK and  UCOE . and the UCA3RXBUF = 0x00, but no interrupt

    ISR code is:

    //------------------------------------------------------------------------------
    #pragma location = "COMMO_RX"   
    #pragma vector=USCI_A0_VECTOR
    __interrupt void USCI_A0_ISR(void)
    {
      switch(__even_in_range(UCA0IV,4))
      {
        char temp;
        
        case 0:
        break;                             // Vector 0 - no interrupt
        case 2:                                   // Vector 2 - RXIFG
       //char temp;
        temp = UCA0RXBUF;
        switch (msgstatus)
        {
          case (none) :
            if(temp==0xEE)
            {
              msgstatus = cmnd;
              RXmsg[0] = temp;
            }
          break;
     
          case (cmnd) :
            RXmsg[1] = temp;
            if((temp==0x1C)||(temp==0x1D)||(temp==0x22)||(temp==0x24)||(temp==0x2A))
            {
              msgstatus = dataln;
              cnt = 2;
            }
            else if(temp == 0x2B)
            {
              msgstatus = var;
              lngth = 0;
              cnt = 2;
            }
            else if(temp == 0x13) //set output voltage
            {  
              msgstatus = var;
              lngth = 0; cnt = 2;
            }
            else if(upgrade && temp==0x26)
            {
                //UGptr = UGRAM_LOWER;
                UGptr=__segment_begin("NEW_CODE");
              UGcnt = 1;
              msgstatus = UGmsg;
            }
            else
            {
              msgstatus = crc1;
            }
          break;
          
          case(crc1) :
            RXmsg[2] = temp;  
            msgstatus = crc2;
          break;
     
          case (crc2) :
            RXmsg[3] = temp;  
            cnt = 4;
            verify();
          break;
     
          case (ack) :
            if(temp==0x06)  msgstatus = none;
          break;
     
          case (dataln) :
            RXmsg[2] = temp;
            lngth = temp;
            cnt++;
            msgstatus = var;
          break;
     
          case (var) :
            {
              RXmsg[cnt++] = temp;
              if(cnt>(lngth + 5)) verify();
              else if((RXmsg[1] == 0x2B) && (cnt > 4)) verify();
              else if((RXmsg[1] == 0x13) && (cnt > 4)) verify();
            }
          break;
     
          case (UGmsg) :
            *UGptr++ = temp;
            UGcnt++;
              if(UGcnt > 519)
                verifyUG();
          break;

          default :
            msgstatus = none;
          break;
      }
       break;

        case 4:                                 // Vector 4 - TXIFG
          __delay_cycles(5000);//(5000);                // Add small gap between TX'ed bytes
         UCA0TXBUF = TXmsg[pmsg++];
         if(nmsg==pmsg) UCA0IE &= ~UCTXIE;                    // disable USCI_A0 TX buffer

          break;
          
        default:
        break;
      }
    }

    The code for the A3 is identical to the A0 (of course it says A3) with the exception of where it is placed in the linker.
      //------------------------------------------------------------------------------
    #pragma location = "USCI_B0"   
    #pragma vector=USCI_A3_VECTOR
    __interrupt void USCI_A3_ISR(void)
    {
      switch(__even_in_range(UCA3IV,4))
      {
        char temp;
        
        case 0:
        break;                             // Vector 0 - no interrupt
        case 2:                                   // Vector 2 - RXIFG
       //char temp;
        temp = UCA3RXBUF;
        switch (msgstatus)
        {
          case (none) :
            if(temp==0xEE)
            {
              msgstatus = cmnd;
              RXmsg[0] = temp;
            }
          break;
     
          case (cmnd) :
            RXmsg[1] = temp;
            if((temp==0x1C)||(temp==0x1D)||(temp==0x22)||(temp==0x24)||(temp==0x2A))
            {
              msgstatus = dataln;
              cnt = 2;
            }
            else if(temp == 0x2B)
            {
              msgstatus = var;
              lngth = 0;
              cnt = 2;
            }
            else if(temp == 0x13) //set output voltage
            {  
              msgstatus = var;
              lngth = 0; cnt = 2;
            }
            else if(upgrade && temp==0x26)
            {
                //UGptr = UGRAM_LOWER;
                UGptr=__segment_begin("NEW_CODE");
              UGcnt = 1;
              msgstatus = UGmsg;
            }
            else
            {
              msgstatus = crc1;
            }
          break;
          
          case(crc1) :
            RXmsg[2] = temp;  
            msgstatus = crc2;
          break;
     
          case (crc2) :
            RXmsg[3] = temp;  
            cnt = 4;
            verifyA3();
          break;
     
          case (ack) :
            if(temp==0x06)  msgstatus = none;
          break;
     
          case (dataln) :
            RXmsg[2] = temp;
            lngth = temp;
            cnt++;
            msgstatus = var;
          break;
     
          case (var) :
            {
              RXmsg[cnt++] = temp;
              if(cnt>(lngth + 5)) verifyA3();
              else if((RXmsg[1] == 0x2B) && (cnt > 4)) verifyA3();
              else if((RXmsg[1] == 0x13) && (cnt > 4)) verifyA3();
            }
          break;
     
          case (UGmsg) :
            *UGptr++ = temp;
            UGcnt++;
              if(UGcnt > 519)
                verifyUG();
          break;

          default :
            msgstatus = none;
          break;
      }
       break;

        case 4:                                 // Vector 4 - TXIFG
          __delay_cycles(5000);//(5000);                // Add small gap between TX'ed bytes
         UCA3TXBUF = TXmsg[pmsg++];
         if(nmsg==pmsg) UCA3IE &= ~UCTXIE;                    // disable USCI_A0 TX buffer

          break;
          
        default:
        break;
      }
    }

    If I have left anything out please let me know. The entire code it too much to download here. We have been using this for several years and it has ~ 12 .C files and a couple ASM files also.

    Thanks again for helping.

    Gerry

  • 0
    Guru 58965 points
    MSP430 in/out signals are 0 to 3.6V. Looks like you are feeding it with RS232 signals. Not only the voltages are too high and too low, the "polarity" is also wrong.

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