Please read this page from the main YASEP interface
version 2014-02-13

BSWAP : Byte SWAP

Change the order of the byte inside a register. This is used to change a word's endianness, for example when transfering data over a network (traditionally Big Endian, while the YASEP is Little Endian)

For YASEP16, the value 1234h will become 3412h.

For YASEP32, the valeu 12345678h will become 78563412h.