MSP430FR2355: SPI

The code that starts a transfer is missing but a couple of thoughts:

1) There is no need for the receive interrupt or reading RXBUF if you don't care about that data. Ignore it.

2) Setting TXIE within the ISR. What is that supposed to do? To execute that code TXIE must already be set.

3) The way you end a transfer is a problem. The way it should be done is after writing the final byte to TXBUF, clear TXIE. Do not wait for the next transmit interrupt. That way the next time you start a transfer, TXIFG is set so that when you set TXIE there is an immediate interrupt. If TXIFG is clear, no interrupt.

Hi, 

I am tried with the suggestions, but still i am facing same issue.

the interrupt was generating only first byte transfer after initializing, after that interrupt not working also the data was transferring outside while i am seeing port pin status on oscilloscope.

My updated code is below:

void spi_init()
{
P4SEL0 |= (BIT5| BIT6 | BIT7); // set 3-SPI pin as second function

//Clock Polarity: The inactive state is high
//MSB First, 8-bit, Master, 3-pin mode, Synchronous
UCB1CTLW0 = UCSWRST; // **Put state machine in reset**
UCB1CTLW0 |= UCCKPL | UCMSB | UCSYNC | UCMST | UCSSEL__SMCLK; // 3-pin, 8-bit SPI Slave
UCB1BRW = 0x20;
UCB1CTLW0 &= ~UCSWRST; // **Initialize USCI state machine**
}

#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=USCI_B1_VECTOR
__interrupt void USCI_B1_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(USCI_B1_VECTOR))) USCI_B1_ISR (void)
#else
#error Compiler not supported!
#endif
{
switch(__even_in_range(UCB1IV,USCI_SPI_UCTXIFG))
{
case USCI_NONE: break; // Vector 0 - no interrupt
case USCI_SPI_UCRXIFG:
UCB1IFG &= ~UCRXIFG;
break;

case USCI_SPI_UCTXIFG:
if(SPI_byte_ptr < SPI_no_of_bytes)
{
UCB1TXBUF = SPI_buffer[SPI_byte_ptr++]; // Transmit characters

}
else
{
UCB1IE &= ~UCTXIE;
}
UCB1IFG &= ~UCRXIFG;
UCB1IFG &= ~UCTXIFG;
break;
default: break;
}
}

int main(void)
{
init();
adc_config();

delay(500);

TB0CCTL0 |= CCIE; //Compare mode
TB0CTL |= TBSSEL_2 | MC_1 | ID_3; //General timer
TB0CCR0 = 2000;
delay(500);

while(1)
{

     if(SPI_update_flag)    //SPI Flag will set for every one seconds once.
    {
          SPI_buffer[0] = 0x11;
          SPI_buffer[1] = 0x0A;
          SPI_buffer[2] = 0x04;
          SPI_update_flag = 0;
          SPI_byte_ptr = 0;
          SPI_no_of_bytes = 3;

          UCB1IE |= UCTXIE;
     }

}