SPI interface between MSP430F5437 and CC1020

Dear all,

I'm new with MSP430F5437 and I'm not able to configure the SPI interface with the transceiver cc1020 (slave). These are the functions that a certain main calls:

//SPI interface initialization on MSP430F5437

void SPI_init(void){  

UCA1CTL1__SPI=UCSWRST; //Clock is denied   

UCB0CTL1__SPI=UCSWRST; //Clock is denied  

UCB1CTL1__SPI=UCSWRST; //Clock is denied  

UCA0CTL1__SPI=UCSWRST; //Clock is denied      

__bis_SR_register(GIE); //interrupts enable    

UCA0CTL0__SPI=UCSYNC | UCMSB | UC7BIT; //set SPI mode, MSB first, the frame is 8 bits long  

UCA0CTL0__SPI_bit.UCMODE0=1;  

UCA0CTL0__SPI_bit.UCMODE1=0;    

UCA0CTL1__SPI_bit.UCSSEL0=1; //clock coming from ACLK  

UCA0CTL1__SPI_bit.UCSSEL1=0;    

UCA0BRW=513; //16 bit to define the divison factor    

UCA0CTL0__SPI_bit.UCMST=1; //clock is provided to cc1020    

UCA0MCTL__SPI=0; //no modulation is required    

UCA0CTL0__SPI_bit.UCCKPL=1; //0 phase and rising clock edge  

UCA0CTL0__SPI_bit.UCCKPH=0;    

UCA0CTL1__SPI&=~UCSWRST; //Clock starts

UCA0IE__SPI = UCTXIE | UCRXIE;

}

//Write a single configuration register of cc1020 by means of SPI

int cc1020_wr(unsigned char address, unsigned char data){  

if(UCA0IFG_bit.UCTXIFG){    

    UCA0TXBUF=(address<<1)|0x01; //Copy address and the WRITE-command into the output register    

    while(!UCA0IFG_bit.UCTXIFG){} //waiting for the end of the last transmission    

    UCA0TXBUF=data; //Copy data the output register    

    while(!UCA0IFG_bit.UCTXIFG){} //waiting for the end of the last transmission    

    return 1;  

}  

 return 0;

}

//Read a single configuration register of cc1020 by means of SPI

unsigned char cc1020_rd(unsigned char address){ 

 if(UCA0IFG_bit.UCTXIFG){    

     UCA0TXBUF=address<<1; //Copy address and the READ-command into the output register    

      while(!UCA0IFG_bit.UCTXIFG && !UCA0IFG_bit.UCRXIFG){} //waiting for the end of the last transmission and the reception from cc1020    

      return UCA0RXBUF;  

 }  

 return '#';

 }

My problem is that neither the flag UCTXIFG nor UCTRXIFG result to be set, so data are never sent.

Thank you!