CCS/EK-TM4C129EXL: SPI Data-sending format

Part Number:EK-TM4C129EXL

Tool/software: Code Composer Studio

Hi,

     I am working with EK-TM4C129EXL evaluation kit. The evaluation kit needs to receive data from external User application and send it to Display system. It receives the data as of now, 

For Example if the received data is 0x7f I am storing this data in the SPI Data buffer and sending this data to external device. 

while sending the data through SPI (i.e. for data 0x7f - 0111 1111) the data stored in Little Endian format but I need the data to be stored in Big endian format. Do I need to set any register bit in SSI registers such that the data can be stored in Big Endian format. (i.e. I need 0x7f to be stored or sent to the external device as 1111 1110 (i.e. as in reverse order 0111 1111))