the writing sequence about TMS570L3137

hi, i have recently implemented an application using  TMS570L3137, when accessing the EMIF, I find that the writng sequence dose not works as the datasheet describes. the thing is that we set the emif as 16bit, when writing, a 16bit data to the emif, the cs3n actives once in the accessing duration, but the emi_wen become active twice during the active of accessing. so what 's the problem? Is  there any register to set for this accessing? thanks in advance.