The approach of the Media Transfer Protocol class addresses some weaknesses of the Mass Storage Device class. File based communication allows access to the file system from the host system (PC) and the device at the same time.

Using the MTP class also allows selectively exposing content of the file system to the host system, typically a PC. Sudden removal of the USB cable does not endanger the data integrity of the device’s file system. On the device side any file system can be used, there is no need for a FAT-compatible file system. Even virtual files can be exchanged with the host via MTP.

“The Media Transfer Protocol class is a significant improvement to the way embedded systems transfer their data to a PC. Being able to select the exposed content and to use a FAT-free and therefore royalty-free file system like emFile EFS are significant advantages for the developer of an embedded system”, says Dirk Akemann, Marketing Manager at SEGGER.

More information about emUSB-Device MTP: www.segger.com/emusb_device_mtp_class.html

About emUSB-Device

emUSB-Device is a high performance USB device stack specifically designed for embedded systems. The flexible device stack allows the creation of multi-class devices using nearly any combination of the provided classes. emUSB-Device provides classes for the Media Transfer Protocol, Mass Storage Device, CDROM, Human Interface Device, CDC (Serial port communication), printer and a sophisticated Bulk communication class. emUSB-Device is fully compliant to the USB-standard. Full product specifications are available at: www.segger.com/emusb.html

About emFile

SEGGER’s emFile is a highly efficient file system optimized for resource usage and performance. Two versions are available, one for FAT-file systems and another for EFS, a proprietary file system which allows the use of long file names without royalties. emFile’s driver level is fail-safe by design, removing the risk of corrupted data. To add fail-safety to the upper file-system, a highly efficient journaling option is available for both EFS and FAT. For security, encryption of either an entire volume or on a file-by-file basis with the highest encryption standards is available. All popular flash media are supported by emFile. Removable media such as SD-Cards, MMC, and CompactFlash are supported, as well as, external flash memories like NOR, NAND, and data flashes. The drivers for the external flash memories include sophisticated wear leveling algorithms. The wear leveling also takes into account that files may be modified at different frequencies. Full product specifications are available at: www.segger.com/emFile.html