BF706 uLaw Companding

My application requires 2 * 16bit u-law compression from SPORT1_A (I2S), but according to "ADSP-BF70x Blackfin + Processor Hardware Reference"-> Serial Port (SPORT)-> Data Types and Companding (31–12)-> Companding as a Function sets SPORT1_A; however, no data is compressed to u-law. Can you tell me how to implement Sport companding (Alaw or uLaw)?
ADI_SPORT_RESULT nRet;
nRet = adi_sport_Open(SPORT_DEVICE,ADI_HALF_SPORT_B,ADI_SPORT_DIR_RX, ADI_SPORT_I2S_MODE, rxDeviceMemory,ADI_SPORT_DMA_MEMORY_SIZE,&rxDevice);
BREAK(nRet);

nRet = adi_sport_ConfigData(rxDevice, ADI_SPORT_DTYPE_COMPAND_A_LAW, 15, false, false, false);
BREAK(nRet);

nRet = adi_sport_MuxHalfSport(rxDevice, false, true);
BREAK(nRet);

nRet = adi_sport_Enable(rxDevice,false);
BREAK(nRet);

uint32_t da=0;

ADI_SPORT_DEVICE* pDevice=(ADI_SPORT_DEVICE*)rxDevice;
pDevice->pSPORTRegs->SPORT_CTL &= (uint32_t)0xFFFFFFFE;//BITM_SPORT_CTL_SPENPRI;
pDevice->pSPORTRegs->SPORT_CTL &= (uint32_t)0xFEFFFFFF;//BITM_SPORT_CTL_SPENSEC;


uint8_t two[4]={0x3f,0x68,0x99,0xf0};
printf("src :%x ; %x ; %x ;%x\r\n",two[0],two[1],two[2],two[3]);

nRet = adi_sport_SubmitBuffer(rxDevice,two,I2S_BUFER_SIZE);
asm("NOP");
asm("NOP");

printf("code:%x ; %x ; %x ;%x\r\n",two[0],two[1],two[2],two[3]);

Regards,
Mao Liang