OMAPL137 NAND-writer problem?

in function LOCAL_flashwirtebytes ,*dest.wp != *src.wp  when *src.wp = 0xAA55 ,the *dest.wp = 0x0055;,I select buswidth = 16; when *src.wp = 0xBBCC, the *dest.wp = 0x00CC;Could you help me solve the problem.