The Mass Storage Device protocol (MSD) is used to get access to one or more storage mediums. Using this class, emUSB-Host provides access to external storage media such as USB-sticks and external hard disk drives, memory card adapters.
A mass storage device connected to emUSB-Host is added to the file system as a volume. All operations on the device, such as formatting, reading / writing of files and directories are performed through the API of the file system. With emFile, the device name of the first MSD is "msd:0:".
Example code which is provided with any shipment or eval software including emUSB-Host. The example shows the capacities of the connected device (such as the volume size, number of sectors, etc.) and shows files in the root directory and creates and writes to a file. Several application samples can also be found on the emUSB-Host sample page.