ads1271 spi interfacing with tm4c129encpdt problem

Hi all,

     I am using tm4c129encpdt controller interfaced with ads1271 ADC ic (single IC). I configured microcontroller with 120MHZ clock speed.

ADS1271 setting -> MODE: high resolution

                                    FORMATE: SPI

First i tried to read ads1271 with gpio pin configuration and  sucessfuly i  read ads1271 with gpio pins.My code is as bellow

while(1)

{

if(GPIOPinREAD(GPIO_PORTD_BASE,GPIO_PIN_4)==0) // DRDY pin

{

for(i=23;i>=0;i--)

{

dt=GPIOPinRead(GPIO_PORTD_BASE,GPIO_PIN_0)==0) // DOUT pin

GPIOPinWrite(GPIO_PORTD_BASE,GPIO_PIN_3,0); // Clock low

GPIOPinWrite(GPIO_PORTD_BASE,GPIO_PIN_3,GPIO_PIN_3); // clock high

data1 = (data1 | (dt<<i) ); // collect data in data1

Delay(5); // 5microsec delay

}

}

}

Now i want to read this ADS1271 ic with SPI configuration. My code is as bellow,

***************************************************************************************************************

SysCtlPeripheralEnable(SYSCTL_PERIPH_SSI2); 

GPIOPinConfigure(GPIO_PD0_SSI2XDATA1); // MISO

GPIOPinConfigure(GPIO_PD3_SSI2CLK); // clock

SSIConfigSetExpClk(SSI2_BASE, 120000000,SSI_FRF_MODE_3,SSI_MODE_MASTER,2000000,8,);

while(1)

{

if(GPIOPinREAD(GPIO_PORTD_BASE,GPIO_PIN_4)==0) // DRDY pin

{

for(i=2;i>=0;i--)

{

SSIDataPut1(SSI2_BASE,DUMMY); // put dummy byte before reading data

while(SSIBusy(SSI2_BASE)); 

SSIDataGet1(SSI2_BASE,&dt); // read 8 bit data

data1 = (data1 | (dt<<i) );

Delay(5); // 5microsec delay

}

}

}

This code is not working please suggest me any solution.

******************************************************************************************************************

Put and get function is as bellow

void SSIDataPut1(uint32_t ui32Base, uint8_t  ui32Data)

{ 

while(!(HWREG(ulBase + SSI_O_SR) & SSI_SR_TNF))
{
}

// Write the data to the SSI.
HWREG(ulBase + SSI_O_DR) = ui32Data; 

}

void SSIDataGet1(unsigned long ulBase, unsigned char*pulData)
{

while(!(HWREG(ulBase + SSI_O_SR) & SSI_SR_RNE))
{
}

// Read data from SSI.
*pulData = HWREG(ulBase + SSI_O_DR);
}