The emUSB-Host software complies with the USB standard specifications as set by the USB Implementors Forum. It supports all transfer modes (control, bulk, interrupt, isochronous) at all speeds. USB pipe management and extended error recovery mechanisms required for reliable operation are implemented internally. Sophisticated test procedures ensure the reliability and quality of the USB host software.
emUSB-Host's modular design enables applications to either access the USB host programming interface directly or to use APIs exposed by class drivers.
emUSB-Host can handle multiple devices as well as hubs simultaneously and fully supports hot plugging of devices and hubs. The programming interface supports dynamic device enumeration and identification.
USB Audio Host class
The emUSB-Host-Audio class allows audio devices, such as microphones, speakers or musical players to communicate with a USB host target. The class allows to record or play audio through the host.
SEGGER's emUSB-Host CCID Class provides an easy-to-use interface to handle smart card readers and communicate with smart cards.
Communication Device Class
The USB Communications Device Class (CDC) provides access to COM port devices via USB. This enables communication via modems for mobile networks such as GSM/3G/LTE or cable based network modems. Any device which uses CDC for configuration and data transmission, such as a point-of-sale terminal, can be accessed via the CDC class driver as well.
FTDI FT232 Device Driver
Many devices formerly connected via UART have been equipped with USB interfaces using serial to UART converters such as the FTDI UART and FT-X devices from FTDI. emUSB-Host is capable of easily addressing such devices.
CP210X Device Driver
Many devices formerly connected via UART have been equipped with USB interfaces using serial to UART converters such as the CP210x USB-to-UART Bridges from Silicon Labs. emUSB-Host is capable of easily addressing such devices.
Human Interface Device class.
The Human Interface Device class (HID) supports the handling of devices which are used by humans to control the operation of computer systems. The class enables the use of input devices such as keyboards, mice, trackballs, touch-controllers, barcode scanners, joysticks, game controllers, RFID readers. And even devices which do not require direct human control such as digital thermometers, software protection dongles, uninterruptible power supplies.
The USB class protocol for MIDI is used to interact with music devices and studio equipment, such as MIDI controllers, sequencers, drum machines, samplers, effects units, synthesizers, instruments, lighting and recording equipment.
Mass Storage Device Class
The Mass Storage Device class (MSD) is used to get access to external storage media such as USB-sticks, external hard disk drives and memory card readers.
Media Transfer Protocol
The Media Transfer Protocol (MTP) can be used to transfer files to and from storage devices like digital cameras or smartphones.
The USB class protocol for printers is used for the handling of output devices, like printers and plotters.
SEGGER's emUSB-Host Vendor Class provides an easy-to-use interface to devices running custom or proprietary protocols.
- Low cost: The USB connector and the corresponding components are normally cheaper than alternative communication interfaces.
- Reliable: The USB protocol contains measures to ensure data integrity. Errors are detected by the sender and data can be retransmitted.
- Versatile: USB host allows to connect with virtually any other technology. Using a USB host port network connectivity can be added by connecting an Ethernet-over-USB adapter. User input can be added by connecting an external USB display, USB keyboard and USB mouse. Storage capacity can be extended by connecting an MSD stick or hard drive.
- Fast: Multiple speed modes are provided by the USB protocol to accommodate the application's needs.
- Expandable: USB hubs can be used to connect multiple devices to a USB host.
- Easy to use: The end user only has to connect a cable, a USB device is enumerated without the need for user configuration.
SEGGER's USB host stack designed to work on any embedded system with a USB host controller. Bulk communication along with all other transfer modes is supported. All commonly used standard device classes are supported. USB trees with multiple hubs are supported as well.
emUSB-Host consists of three layers. These layers are a driver for hardware access, the emUSB-Host core, and at least one USB protocol layer.
|USB protocol layer|
|CDC||emUSB-Host Communication Device Class component.|
|HID||emUSB-Host Human Interface Device Class component.|
|MSD||emUSB-Host Mass Storage Device Class component.|
|Printer||emUSB-Host Printer component.|
|FT232||emUSB-Host FTDI UART component.|
|MTP||emUSB-Host Media Transfer Protocol component.|
|Vendor||emUSB-Host Vendor class component.|
|LAN||emUSB-Host LAN component.|
|CCID||emUSB-Host CCID class component.|
|MIDI||emUSB-Host MIDI class component.|
|CP210x||emUSB-Host CP210x UART support.|
|Audio||emUSB-Host Audio component|
|emUSB Core||The emUSB-Host core is the intrinsic USB stack|
|Driver||USB controller driver|
emUSB-Host does not contain any hardware dependencies. These are encapsulated through a hardware abstraction layer, called a driver. In order to manage the number of required drivers, emUSB-Host has a flexible driver concept, that supports almost all host controllers in the market. For a complete list of currently supported controllers, press the button below. If a controller is not listed, please feel free to contact us about adding support.
SEGGER recommends to purchase emUSB-Host as a complete package by selecting the emUSB-Host PRO package. It includes support for the most common use cases, such as handling human interface devices for user interaction, handling USB sticks to export and import data, printer support and serial communication support. The following table shows, which modules are part of the PRO package and which are optionally available.
One item included