A removable electronic device includes a detector for detecting a mode of
operation to distinguish among a multimedia card (MMC) compatible mode, a
universal serial bus (USB) compatible mode, and a Mu mode, a wrapper for
converting data for transfer between the USB compatible mode and the Mu
mode, a USB physical layer circuit for transferring data compatible with
the USB compatible mode, a USB compatible device controller for
controlling data transfer in the USB compatible mode, and an MMC
compatible device controller for controlling data transfer in the MMC
compatible mode.