Janghong,
The TSW1400 supports two different 16-bit DDR LVDS data. This is to primarily support the DAC34H84 so that TX1 (Channel AB) can have different data than TX2 (channel CD).
The TSW1400 can only connect to one DAC EVM at a time. To support two EVMs simultaneously, you will need to create an adapter yourself.
Also, the TSW1400 cannot support two TSW3085 (with two DAC3482) since it does not have extra DATACLK and FRAME signal to support the 2nd DAC3482.
You will need to modify the firmware or external hardware slightly to support this. Also, we do not have adapter boards that can split the bus to connect to two EVMs at the same time. You will need to account for this in your design/project.
-Kang