TPL0501-100 - SPI communication

Hi, I'm getting a hard time trying to communicate with this digital potentiometer. I'm using a Tiva Launchpad TM4C123G. I'm still not quite familiar in establish this type of communication. But I did some code and I'd appreciate some guidance. I tested but I've got nothing. 

This is what I've done:

void init_SSI(void)
{

void init_SSI(void)
{
	//Enable SSIO Peripheral
	SysCtlPeripheralEnable(SYSCTL_PERIPH_SSI0);

	//Enable GPIOA Peripheral 
	SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);
	
	//Configures the alternate function of a GPIO pin.
	GPIOPinConfigure(GPIO_PA2_SSI0CLK);
	GPIOPinConfigure(GPIO_PA3_SSI0FSS);
	GPIOPinConfigure(GPIO_PA5_SSI0TX);
	
	//Configures pin(s) for use by the SSI peripheral.
	GPIOPinTypeSSI(GPIO_PORTA_BASE, GPIO_PIN_2 | GPIO_PIN_3 | GPIO_PIN_5);
	
	//Selects the advanced mode of operation for the SSI module.
	SSIAdvModeSet(GPIO_PORTA_BASE, SSI_ADV_MODE_WRITE);	
	
	//Configures the synchronous serial interface.
	SSIConfigSetExpClk(SSI0_BASE, 100000, SSI_FRF_MOTO_MODE_2, SSI_MODE_MASTER, 50000, 8);
	
	//Enable the SSIO
  SSIEnable(SSI0_BASE);
	
}
void Delay(unsigned long ulCount){
  do{
    ulCount--;
	}while(ulCount);
}
void send_SSI(uint32_t dado)
{	
	SSIDataPut(SSI0_BASE, dado);
	while(SSIBusy(SSI0_BASE)); // wait until SSI0 not busy
		
}

int main (void)
{
	init_SSI();
	
	while(1)
	{
		int i = 0;	
		for(i=0; i <=255; i++)
		{
			send_SSI(i);
			Delay(5000000);
		}
		for(i=255; i > 0; i--)
		{
			send_SSI(i);
			Delay(5000000);
		}		
			
	}
}