I2S was defined by Philips for connections between chips in digital devices like CD players. It was not intended for use as an interconnection between transport and DAC since the definition was primarily of the signal logic. It was later adapted by manufacturers, originally by Audio Alchemy, for that purpose. It does not "split" the clock and data signals; rather it keeps them separate as they come from the decoder or digital filter. It is the S/PDIF format which combines them.
