The SAM3U is the first product to implement a high-speed version of the Microchip multimedia card interface. This version is compatible with all revisions of the MMC and SD/SDIO specifications, as well as those including high speed and high capacity modes. The SAM3U also integrates a dedicated MCI I/O for the clock that runs at up to 45MHz at 1.8V and up to 65MHz at 3.0V with a load capacitance of 30 pF. The SAM3U two-wire interface (TWI) supports master, slave and multi-master modes, as well as a quick SMBus command, which is part of the I²C standard. Additionally, PDC-DMA support has been added on the SAM3U implementation of the TWI.