SEGGER emUSB-Device & emUSB-Host
Embedded SoftwareComplete USB stack covering device and host roles with CDC, HID, MSD, Audio, RNDIS, composite device support, hub management, and USB-C Power Delivery negotiation. India pricing available from GSAS.
Device Classes
CDC, HID, MSD, Audio, Printer, RNDIS
Host Classes
MSD, HID, CDC, Printer, Hub
Composite
Multi-class device support
USB-C PD
Power Delivery negotiation
Speed
Full-speed and high-speed
License
Royalty-free
Overview
About emUSB-Device & emUSB-Host
- Type
- USB device + host stack
- Standards / Classes
- CDC, HID, MSD, Audio, Printer, RNDIS
- Footprint
- Full-speed and high-speed
- License
- Royalty-free
SEGGER emUSB provides a complete USB software stack for embedded systems, covering both device and host roles in a unified, royalty-free package.
USB Device Classes
emUSB-Device enables microcontrollers to appear as USB peripherals to host computers. Composite device support allows multiple USB classes to operate simultaneously on a single connection.
| Class | Function | Typical Application |
|---|---|---|
| CDC-ACM | Virtual COM port | Serial communication, debug console, AT command interface |
| HID | Human Interface Device | Custom sensors, keyboard/mouse emulation, control panels |
| MSD | Mass Storage Device | Expose internal flash or SD card as a removable drive |
| Audio | Audio streaming (UAC) | Microphone input, speaker output, audio processing |
| Video | Video streaming (UVC) | Camera devices, video inspection equipment |
| Printer | Printer class | Direct print from host without drivers |
| MTP | Media Transfer Protocol | Media file management with metadata support |
| Bulk | Vendor-specific bulk | High-throughput custom data transfer protocols |
| RNDIS | Network over USB | Ethernet-over-USB for network connectivity |
Dual-Role USB Support
emUSB-Host turns the same microcontroller into a USB host capable of enumerating and communicating with connected peripherals including flash drives, keyboards, mice, barcode scanners, and printers. Hub support allows multiple downstream devices on a single host port, and USB-C Power Delivery negotiation enables intelligent power management for devices that need to negotiate voltage and current profiles, increasingly relevant as Indian electronics manufacturers adopt USB-C across consumer, industrial, and automotive product lines.
| Host Class | Supported Devices |
|---|---|
| MSD | USB flash drives, external hard drives, card readers |
| HID | Keyboards, mice, barcode scanners, custom HID devices |
| CDC | USB-serial adapters, modems |
| Printer | USB printers |
| Hub | Multi-port hubs for downstream device expansion |
Full-speed and high-speed operation is supported across both device and host stacks, with USB On-The-Go (OTG) enabling a single USB port to dynamically switch between host and device roles.
Architecture and Integration
Watch the SEGGER emUSB introduction
Both stacks are designed for deterministic behavior in real-time environments and integrate tightly with embOS for interrupt-driven, thread-safe operation. The driver abstraction layer supports silicon vendors’ USB peripheral controllers directly, eliminating dependence on vendor-specific HAL libraries that can introduce version lock-in. Royalty-free licensing applies to both emUSB-Device and emUSB-Host, keeping per-unit costs at zero regardless of how many USB-enabled products ship from the production line.
Blog
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FAQ
Common questions about emUSB-Device & emUSB-Host
What is SEGGER emUSB?
Is emUSB royalty-free?
Which SEGGER middleware for USB-C Power Delivery or dual-role USB?
Can I buy SEGGER emUSB in India?
Does emUSB support both full-speed and high-speed USB?
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