MSP430 SPI Slave Example

Other Parts Discussed in Thread: MSP430F5529, MSP430WARE

Hello,

I have a MSP430F5529 Launch Pad Evaluation Kit (using CC5.5).  I am trying to get the SPI slave example in 

C:\TI_CC55\MSP430ware_1_97_00_47\driverlib\examples\MSP430F5xx_6xx\usci_b_spi\CCS working.  I made changes to use the correct linker.cmd, etc. for the 5529 part.

The issue I am having is that I am not getting any receive interrupts.

The Evaluation Kit is attached via SPI to another board acting as the MASTER (MODE 0).  I have verified that the data coming from the MASTER into the Evaluation Kit is correct via a scope.

The pins I am using on the Evaluation Kit are:

The code is as follows (pretty much verbatim from the TI example):

void main(void)
{
   //Stop watchdog timer
   WDT_A_hold(WDT_A_BASE);

   //If clock signal from master stays low, it is not yet in SPI mode
   while(GPIO_INPUT_PIN_LOW ==
            GPIO_getInputPinValue(
            GPIO_PORT_P3,
            GPIO_PIN2
          ))
   {
      ;
   }

   GPIO_setAsPeripheralModuleFunctionInputPin(
                            GPIO_PORT_P3,
                            GPIO_PIN1 + GPIO_PIN2 + GPIO_PIN0
                            );

   //Initialize slave to MSB first, inactive high clock polarity and 3 wire SPI
   returnValue = USCI_B_SPI_slaveInit(USCI_B0_BASE,
                              USCI_B_SPI_MSB_FIRST,
                              USCI_B_SPI_PHASE_DATA_CHANGED_ONFIRST_CAPTURED_ON_NEXT,
                              USCI_B_SPI_CLOCKPOLARITY_INACTIVITY_LOW
                              );

   if(STATUS_FAIL == returnValue)
   {
      return;
   }

   //Enable SPI Module
   USCI_B_SPI_enable(USCI_B0_BASE);

   //Enable Receive interrupt
   USCI_B_SPI_clearInterruptFlag(USCI_B0_BASE,
                               USCI_B_SPI_RECEIVE_INTERRUPT
                               );
   USCI_B_SPI_enableInterrupt(USCI_B0_BASE,
                               USCI_B_SPI_RECEIVE_INTERRUPT
                               );

   //Enable interrupts
   __bis_SR_register(GIE);

}

#pragma vector=USCI_B0_VECTOR
__interrupt
void USCI_B0_ISR(void)
{
   switch(__even_in_range(UCB0IV,4))
   {
   //Vector 2 - RXIFG
   case 2:
   //USCI_A0 TX buffer ready?
   while(!USCI_B_SPI_getInterruptStatus(USCI_B0_BASE,
                    USCI_B_SPI_TRANSMIT_INTERRUPT
                      ))
   {
      ;
   }

   //Transmit data to master
   USCI_B_SPI_transmitData(USCI_B0_BASE,
                         transmitData
                         );

   //Receive data from master
   receiveData = USCI_B_SPI_receiveData(USCI_B0_BASE);

   //Increment data to be transmitted
   transmitData++;

   break;

   default: break;
   }
}

After running and pausing the execution on the Evaluation Kit, the data I see in the USCB0RXBUF_SPI is correct.  I can run and pause and the RX buffer register continues to update with the correct data from the master.  

UCB0IE_SPI shows that the RX interrupt is ENABLED.  

UCB0IFG_SPI shows that there is a receive as well as a transmit interrupt PENDING.

UCB0IV_SPI shows => Interrupt Source: Data received; Interrupt Flag: UCRXIFG; Interrupt Priority: Highest

Any ideas on why my interrupt handler is not being hit?

Any help would be great.

Thanks,

Brent