emUSB-Host

The USB-host software for embedded-device USB peripherals.

1.Overview
2.Key features
1. 2.1.Reliability
2. 2.2.Plug-and-play setup
3. 2.3.Versatility
3.Use cases
1. 3.1.Device control hub
2. 3.2.Point-of-sale peripherals
3. 3.3.PC and multimedia peripherals
4.Components
1. 4.1.Communication
2. 4.2.Multimedia
3. 4.3.Peripheral
4. 4.4.Smart card
5. 4.5.Storage
6. 4.6.UART converter
7. 4.7.Vendor
5.Drivers and supported controllers
6.emPower-USB-Host+
7.Performance

Overview

emUSB-Host software enables USB peripherals to work with embedded devices. It provides full USB-host functionality, including external hub support and device-class drivers as an option. The software complies with USB standard specifications as set by the USB Implementors Forum, and it supports all transfer modes (control, bulk, interrupt, and isochronous) at all speeds.

USB pipe management and extended error recovery mechanisms are implemented internally to ensure reliable operation. Furthermore, sophisticated test procedures ensure quality and dependability. Modular design enables applications to either access the USB-host programming interface directly, or to use APIs made available by class drivers.

emUSB-Host can manage multiple devices and hubs simultaneously, and it fully supports device and hub hot plugging. The programming interface supports dynamic device enumeration and identification. With emUSB-Host, developers can seamlessly integrate USB functionality into embedded systems.

Key features

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Reliability

emUSB-Host implements internal USB pipe-management and extended error-recovery mechanisms. These ensure reliable and consistent operation.

Furthermore, sophisticated test procedures ensure quality and dependability for any situation.

A teal circular icon featuring three simplified human figures: two figures are positioned above and to the left and right, while one figure is centered below. The design emphasizes connection or interaction among the figures.

Plug-and-play setup

Setting up emUSB-Host is as easy as plug-and-play. New devices are automatically detected and enumerated, and respective target applications notified of their presence.

Device removal is just as simple, and emUSB-Host even ensures that all transfers are cancelled, before “cleaning up” afterwards. Integration is hassle free, as enumeration is handled in the application.

White USB symbol on a teal circular background, representing a USB connection. The symbol features a circle, a triangle, and a square, indicating data transfer and connectivity.

Versatility

emUSB-Host supports a wide range of USB classes and devices — even proprietary third-party classes. For proprietary USB vendor-class-specific implementations, the dedicated “USB vendor class component” can assist.

Connecting multi-interfaces devices is trouble free, as each interface has a dedicated class handler.

Use cases

Apps can dynamically extend a host’s capabilities or enable customization by manufacturers, OEMs, and end customers. Use cases include test apps, communications (web server, customization), automation, and many more.

Device control hub

emUSB-Host host can function as a device control hub by working together with other SEGGER products, such as Flasher Hub-4, Flasher Hub-12, and Flasher Compact.

The image depicts a central control panel with buttons, connected to three blue devices below: a Flasher Hub-12, a Flasher Hub-4, and a Flasher Compact, each with different features indicated. The layout illustrates how these components interact within a system.

Icon depicting two figures representing users alongside a package and a cube connected by lines, symbolizing collaboration and structured data organization. The design conveys themes of teamwork and efficient logistics or information flow.

Point-of-sale peripherals

emUSB-Host is used in commercial and retail environments to enable connection to point-of-sale peripherals such as scanners, cash-register drawers, card readers, and more.

PC and multimedia peripherals

emUSB-Host enables connection with a wide range of PC peripherals, including webcams, mice, keyboards, speakers, printers, modems, docking stations, and more.

A graphic displaying a computer monitor with icons representing various peripherals: a printer, speakers, a webcam, a keyboard, and a mouse. The icons are arranged in a grid format against a teal background, emphasizing connections to essential computer components.

Components

SEGGER's USB host stack works on any embedded system with a USB host controller. All transfer modes, commonly used standard device classes, and USB trees with multiple hubs are supported.

emUSB-Host consists of three layers: A driver for hardware access, the core, and at least one USB protocol layer. SEGGER recommends purchasing emUSB-Host as a complete bundle by selecting the emUSB-Host PRO package. This includes support for the most common use cases, such as human interface devices for user interaction, USB sticks for exporting and importing data, printer support, and serial-communication support.

Communication

CDC

These protocols provide access to COM port devices and allow device-to-device communication via USB. They also enable communication for mobile networks such as GSM, 3G, LTE, and cable-based network modems.

LAN

emUSB-Host LAN provides support for a multitude of ethernet-over-USB adapters, which enable network access for any embedded system with a USB host.

A modern city skyline is visible in the background, with a clear blue sky above and a road in the foreground. Graphical lines and circles represent connectivity and technology, symbolizing urban infrastructure and digital networks. The image conveys themes of innovation and communication in urban settings.

Multimedia

Audio

The audio protocol enables communication with any Audio 1.0 device that complies with the USB Device Class Definition for Audio Devices as specified by the USB Implementers Forum.

MIDI

This protocol is for music devices using the MIDI interface via USB. Devices here include MIDI controllers, MIDI sequencers, drum computers, instruments, effect units, samplers, and synthesizers.

Peripheral

HID

The Human Interface Device protocol enables use of (custom and vendor-specific) input devices, such as keyboards, mice, trackballs, and touch controllers.

Printer

This protocol covers handling of output devices, such as printers and plotters.

Two gaming controllers are positioned on a split background of teal and orange. The controllers feature a mix of buttons and a joystick, with one having an orange accent and the other a contrasting design. They symbolize gaming and entertainment.

Smart card

A person is using a card reader, holding a blank card above it. The card reader has a numeric keypad and a screen, indicating a transaction. A plant is visible in the background, adding a casual ambiance to the scene.

CCID

The Chip Card Interface Device protocol allows enumeration and communication with any CCID compatible USB device, such as a smart-card reader.

Storage

MSD

The Mass Storage Device protocol is used to obtain access to one or more storage mediums.

MTP

The Media Transfer Protocol is used to transfer files to and from storage devices.

A flat lay of various data storage devices is displayed on a black background. Items include an SD card, a USB flash drive, an external hard drive with a ribbed design, a floppy disk, and a CD.

UART converter

An image of a USB connector is prominently displayed against a dynamic, blurred blue and red background, suggesting speed and technology. The USB connector features a rectangular design with a shiny metallic base and two circular ports on one side.

CH34X

This protocol offers compatibility with a wide range of WCH CH34x devices.

CP210X

This protocol offers compatibility with a wide range of CP210x devices.

FT232

This protocol offers compatibility with a wide range of FT232 devices.

Vendor

Vendor/custom

The Vendor protocol enables detection and communication with any device, typically those running a custom or proprietary protocol.

The image shows two USB flash drives, one gray and one white, placed on a textured surface. A laptop is visible in the background, highlighting its USB ports. The setting conveys a theme of digital storage and technology.

Drivers and supported controllers

emUSB-Host has no hardware dependencies; these are encapsulated through a hardware abstraction layer called a driver.

In order to manage the number of drivers required, emUSB-Host has a flexible driver concept that supports almost all host controllers on the market. A complete list of currently supported drivers is available below. If a controller is not listed, it can be added by contacting SEGGER customer support.

List of drivers and controllers

emPower-USB-Host+

emPower-USB-Host+ is a low-cost board for applications that require two USB-Host ports in a simple and streamlined design. SEGGER software such as emUSB-Host, emLoad, and embOS is ready to run on the board.

The board is accessible via debug probe and use of J-Link OB on the board.

More information

Performance

Performance metrics for read and write speeds, based on system configuration.

More information

Licensing

A digital graphic promoting a sale with a bold "25% off 2nd seat*" message at the top, and a prominent "FREE Professional Tools" note at the bottom, indicating availability for non-commercial use. The background features a pattern of binary code.

emUSB-Host is available under various embedded software license models and delivered in object and source-code packages. With a wide range of licensing options, emUSB-Host can fulfill both commercial and technical requirements.

All licenses are obtained through one-time payments. emUSB-Host is royalty free and is not subscription based, meaning that software is a part of equipment expenses, keeping costs static. emUSB-Host licenses include six months of updates and support from SEGGER's Embedded Experts.

* Applies only to a second license and any additional license(s) purchased for the same product under the Single Product License and Single Developer License.

Friendly License

emUSB-Host is also available under SEGGER's Friendly License, which allows free-of-charge use for non-commercial, evaluation, and educational purposes. With this license, the product is fully functional and there are no technical limitations. To download the license, please visit https://www.segger.com/downloads/emusb-host/.

Request a quote Detailed pricing information

FAQ

Why should I use a USB host stack in my embedded system?

There are numerous advantages to adding emUSB-Host to hardware; some of these include:

Low cost: A USB connector and corresponding components are typically less expensive to purchase than alternative communication interfaces.
Reliability: The USB protocol ensures data integrity. Errors are detected by the sender, and data can be retransmitted, if needed.
Versatility: emUSB-Host allows connection with virtually any other technology. Use of a USB-host port network with an Ethernet-over-USB adapter adds connectivity. User-input functionality can be added via connection with an external USB display, keyboard, and mouse. Storage capacity is extendable via MSD stick or hard drive.
Adaptable speeds: The USB protocol provides multiple speed modes to accommodate an application's needs.
Expandable: USB hubs can connect multiple devices to a USB host.
Ease of use: End users need only connect a cable; a USB device is enumerated with no need for user configuration.

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