I am planning a device that takes automatic backup of some instrumentation data from an SDHC card to a portable HDD (USB 3.0 / USB 2.0 removable hard-disk). The idea is to insert the SD card into the case, press a button and copy certain files on the FAT32 formatted SD card to the Hard-disk into a set of pre defined folders.
I am targeting a speed of 480 Mbps. I have only limited knowledge of the USB system. I know that I need a Host Controller (Something like a Vinculum) and a USB hub to create two USB ports.
My doubt is do I need one Host Controller or Two Host Controllers to make the transfer between the two connected USB Mass storage devices operate on High-Speed (i.e 480 Mbps) ?