CCS/TM4C1294NCPDT: SSI problem on TM4C1294NCPDT

Part Number:TM4C1294NCPDT

Tool/software: Code Composer Studio

I have some problems on SSI of TM4C1294NCPDT on Tiva™ EK-TM4C1294XL Launchpad. The SSI is set as master, when transmitting data, the SSI do not work. The pin clock (PA2) do not change. I use the code provided by TI workshop as below. When running to the code 'SSIDataPut(SSI0_BASE, ui32Data)', all the SSI pins on chip do not change, and the register of SSIDR always stays zero. Could you please help me to figure out the problem. Thanks in advance...

#include<stdint.h>

#include<stdbool.h>

#include"inc/hw_memmap.h"

#include"inc/hw_ssi.h"

#include"inc/hw_types.h"

#include"driverlib/ssi.h"

#include"driverlib/gpio.h"

#include"driverlib/pin_map.h"

#include"driverlib/sysctl.h"

uint32_t ui32SysClkFreq;

#define NUM_SSI_DATA 8

constuint8_t pui8DataTx[NUM_SSI_DATA] =

{0x88, 0xF8, 0xF8, 0x88, 0x01, 0x1F, 0x1F, 0x01};

// Bit-wise reverses a number.

uint8_t

Reverse(uint8_t ui8Number)

{

uint8_t ui8Index;

uint8_t ui8ReversedNumber = 0;

for(ui8Index=0; ui8Index<8; ui8Index++)

{

ui8ReversedNumber = ui8ReversedNumber << 1;

ui8ReversedNumber |= ((1 << ui8Index) & ui8Number) >> ui8Index;

}

return ui8ReversedNumber;

}

intmain(void)

{

uint32_t ui32Index;

uint32_t ui32Data;

ui32SysClkFreq = SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ | SYSCTL_OSC_MAIN | SYSCTL_USE_PLL | SYSCTL_CFG_VCO_480), 120000000);

SysCtlPeripheralEnable(SYSCTL_PERIPH_SSI0);

SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);

GPIOPinConfigure(GPIO_PA2_SSI0CLK);

GPIOPinConfigure(GPIO_PA3_SSI0FSS);

GPIOPinConfigure(GPIO_PA4_SSI0XDAT0);

GPIOPinTypeSSI(GPIO_PORTA_BASE,GPIO_PIN_4|GPIO_PIN_3|GPIO_PIN_2);

SSIConfigSetExpClk(SSI0_BASE, ui32SysClkFreq, SSI_FRF_MOTO_MODE_0, SSI_MODE_MASTER, 10000, 16);

SSIEnable(SSI0_BASE);

while(1)

{

for(ui32Index = 0; ui32Index < NUM_SSI_DATA; ui32Index++)

{

ui32Data = (Reverse(pui8DataTx[ui32Index]) << 8) + (1 << ui32Index);

SSIDataPut(SSI0_BASE, ui32Data);

while(SSIBusy(SSI0_BASE))

{

}

}

}

}