edma3 lld event trigger

Hello I have configed the edma3 to transfer data using event trigger on tms320c6455, and I want to using the pingpong mechinsm,so I got the paramhandle,when I received an entire frame data ,I changed the edma3 transfer DST from ping to pong(or pong to ping)using paramhandle,but I found it failed ,so I doubt my operation is wrong, my doubt is that if I have enabled the edma3 transfer data using event trigger mode, can I change the paramSet , for example I change the , DST when the entire data is received, if it can't, how can I implement the ping pong transfer using event trigger not link or chain mode, because my data is cut into 32 blocks,after every block data is ready,a gpio event will generate to trigger the edma3 transfer,can somebody help me,thank you!