CCS/MSP430G2744: SPI in 3-pin configuration. What's the problem?

void  configurazione_SPIprova() {
	unsigned int Configuration_Write;
    P3DIR |= BIT0|BIT1|BIT2|BIT3|BIT4;
    P3OUT |= BIT4;
    P3SEL = BIT0|BIT4|BIT5;
    //P3REN |= BIT6;
    UCA0CTL1 |= UCSWRST;
    UCA0CTL0 |= UCCKPH+UCMSB+UCMST+UCSYNC; // 3-pin, 8-bit SPI master
    UCA0CTL1 |= UCSSEL_2; // SMCLK
    UCA0BR0 |= 32; // /32
    UCA0BR1 = 0;
    UCA0MCTL = 0; // No modulation
    UCA0CTL1 &= ~UCSWRST; // **Initialize USCI state machine**
    Configuration_Write = 0x80;
    P3OUT &= (~BIT3); // Select Device
    while (!(IFG2 & UCA0TXIFG)); // USCI_A0 TX buffer ready?
    UCA0TXBUF = Configuration_Write; // Send 0x80 over SPI to MAX31865 to write on its internal Configuration_Register
    while (!(IFG2 & UCA0TXIFG));
    UCA0TXBUF=0x91;		//Write in the Configuration_Register to set VBias, Conversion Mode and Filter's Frequency bits
    REG_MAX31865[0]=UCA0TXBUF;		//Store the value in an array
    P3OUT |= (BIT3); // Unselect Device
    P3OUT &= (~BIT3); // Select Device
    UCA0TXBUF=0x83;		//Send the address of the next register I want to write
    UCA0TXBUF=0xFF;
    REG_MAX31865[3]=UCA0TXBUF;
    P3OUT |= (BIT3); // Unselect Device
    P3OUT &= (~BIT3); // Select Device
    UCA0TXBUF=0x84;
    UCA0TXBUF=0xFF;
    REG_MAX31865[4]=UCA0TXBUF;
    P3OUT |= (BIT3); // Unselect Device
    P3OUT &= (~BIT3); // Select Device
    UCA0TXBUF=0x85;
    UCA0TXBUF=0x00;
    REG_MAX31865[5]=UCA0TXBUF;
    P3OUT |= (BIT3); // Unselect Device
    P3OUT &= (~BIT3); // Select Device
    UCA0TXBUF=0x86;
    UCA0TXBUF=0x00;
    REG_MAX31865[6]=UCA0TXBUF;
    P3OUT |= (BIT3); // Unselect Device
}

void LetturaSPI_Prova() {
	unsigned int Configuration_Read;
    P3OUT &= (~BIT3); // Select Device
    Configuration_Read=0x00;
    while (!(IFG2 & UCA0TXIFG)); // USCI_A0 TX buffer ready?
    UCA0TXBUF = Configuration_Read;
    while (!(IFG2 & UCA0TXIFG));
    UCA0TXBUF=0x01; //This is the read address I need to read
    RTD_MSB=UCA0RXBUF;		//I store the value in RTD_MSB
    UCA0TXBUF=0x02;
    RTD_LSB=UCA0RXBUF;


    RTD=(RTD_LSB| (RTD_MSB<<8)); //I unify MSB and LSB to obtain a 16-bit value
    P3OUT |= (BIT3); // Unselect Device
}

void Get_Temperatura() {	//Finally I do the conversion from RTD (resistance value) to the temperature, as written on MAX31865 datasheet
	unsigned int ADC_CODE;
	unsigned int temperatura;
	ADC_CODE=(RTD>>1);
	temperatura=(ADC_CODE/32)-256;
}

int main(void) {
	WDTCTL = WDTPW | WDTHOLD;	//watchdog_disable();
/* Inizializzo lo stack pointer al valore 0x5FF in fondo alla RAM */
	__asm (" MOV.W   #0x0600,SP");
	clear_RAM();
	delay_watchdog (wdt_delay);
	watchdog_enable();
	configurazione_iniziale();
	display_initialization();
	configurazione_SPI();
	trasmissione_CONFIGURAZIONI();
	FREE=0; //Is a counter linked with 100ms timer
	while (1) {
		 	watchdog();
		 	if(FREE>5) { //Wait 500ms
			Lettura_SPI();
			FREE=0;
		 	}
	}
}

void configurazione_SPI() {
    P3DIR |= BIT0|BIT1|BIT2|BIT3|BIT4;
    P3OUT |= BIT4;
    P3SEL = BIT0|BIT4|BIT5;
    P3REN |= BIT6;
    UCA0CTL1 |= UCSWRST;
    UCA0CTL0 |= (UCCKPH+UCMSB+UCMST+UCSYNC); // 3-pin, 8-bit SPI master
    UCA0CTL1 |= UCSSEL_2; // SMCLK
    UCA0BR0 |= 32; // /32
    UCA0BR1 = 0;
    UCA0MCTL = 0; // No modulation
    UCA0CTL1 &= ~UCSWRST; // **Initialize USCI state machine**
}

void trasmissione_CONFIGURAZIONI() {
	unsigned int Configuration_Write;
    Configuration_Write = 0x80;
    P3OUT &= (~BIT3); // Select Device
    UCA0TXBUF=(Configuration_Write);	// Send 0x80 over SPI to MAX31865 to write on its internal Configuration_Register
    while (!(IFG2 & UCA0TXIFG));
    UCA0TXBUF=CONREG_MAX50;		//Write in the Configuration_Register to set VBias, Conversion Mode and Filter's Frequency bits
    while (!(IFG2 & UCA0TXIFG));
    UCA0TXBUF=0x00;
    while (!(IFG2 & UCA0TXIFG));
    UCA0TXBUF=0x00;
    while (!(IFG2 & UCA0TXIFG));
    UCA0TXBUF=0xFF;
    while (!(IFG2 & UCA0TXIFG));
    UCA0TXBUF=0xFF;
    while (!(IFG2 & UCA0TXIFG));
    UCA0TXBUF=0x00;
    while (!(IFG2 & UCA0TXIFG));
    UCA0TXBUF=0x00;
    while (!(IFG2 & UCA0TXIFG));
    UCA0TXBUF=0x00;
    while (!(IFG2 & UCA0TXIFG));
    loop_delayREAD();

    P3OUT |= (BIT3); // Unselect Device
}

//loop_delayREAD is an asm function for a little delay
loop_delayREAD:	mov.w	#0x20, R4
loop_delay:	dec R4
		jnz loop_delay
		ret

void Lettura_SPI() {
	unsigned char count;
	unsigned char var[8];
    Configuration_Read= 0x00;
    P3OUT &= (~BIT3);
    loop_delayREAD();
    UCA0TXBUF=0x00;
    while (!(IFG2 & UCA0TXIFG));
    UCA0TXBUF=0x00;
    while (!(IFG2 & UCA0TXIFG));
    for(count=0; count<8; count++) {
    	UCA0TXBUF=(0x00+count);
    	while (!(IFG2 & UCA0TXIFG));
    	var[count]=UCA0RXBUF;
    	}
    	loop_delayREAD();
    	P3OUT |= (BIT3);
    }

/*var[1] and var[2] should be my RTD_MSB and RTD_LSB respectively but what I read isn't correct*/