USB Solutions for INTEGRITY

Green Hills Software offers complete, high-performance USB 3.0 host, device, and On-the-Go (OTG) solutions for the INTEGRITY RTOS. Both Host and Device (Function) stacks are available in addition to numerous class drivers and example applications for using both stacks. The stacks and drivers are all delivered with full source code. These products allow developers to quickly and easily add USB connectivity to INTEGRITY based devices.

Supported USB standards
USB 1.1, USB 2.0, HSIC USB, USB 3.0, USB 3.1, SSIC USB, USB Type C

Supported speeds
Low speed, full speed, high speed, USB 3.1 Gen 1 and Gen 2
(SuperSpeed and SuperSpeed Plus).

Supported hubs
USB 1.1, USB 2.0 (including transaction translators), USB 3.0, USB 3.1

Host Stack

Responsible for enumerating host-connected USB devices
Provides data transfer mechanisms via a simple API for Control, Interrupt, Bulk, Isochronous, and USB 3 bulk streams
Interfaces to Host Class Drivers
OHCI, UHCI, EHCI, and xHCI compliant
USB 1.1 supports full speed (UHCI) 12Mb/s and low speed (OHCI) 1.5Mb/s data rates.
USB 2.0 is backward compatible with USB 1.1 and adds support for the high-speed (EHCI) 480Mb/s data rate
USB 3.0 is backward compatible with USB 2.0 and adds support for High-Speed Inter-Chip (HSIC) USB (480Mb/s) and SuperSpeed Inter-chip (SSIC) USB (10Gb/s) for chip-to-chip applications
Class Drivers include:
- Hub
- Composite
- Mass storage (mass storage driver only works on INTEGRITY)
- HID (keyboard and mouse)
- Virtual Serial Port
- ACM and DSRC Modems
- Audio 1.1 and Audio 2.0 for USB Headsets
- Wi-Fi over USB
- Ethernet over USB (EEM, ECM, NCM)

Device (Function) Stack

USB 1.0 through USB 3.1 and Microsoft OS descriptor support
Device-controller drivers available for a variety of register models
Support for all defined USB speeds, alone or in combination: low speed, full speed, high speed, SuperSpeed, and SuperSpeed Plus
Implements standard USB control requests
Provides data transfer services to device class drivers
Notifies device class drivers of transfers initiated by the host
By nature, device class drivers are very unique to each device. Green Hills Software provides source code examples of generic mouse, serial, and mass storage device class drivers that you can use to implement your own unique USB based peripherals. Custom device class drivers can also be developed for you by Green Hills Software's consulting services organization.

Dual Role Host/Device Support

It is increasingly common to multiplex a single physical USB connector to operate it either as a host or device. To support this, the stack has complete support for dual-role USB Type C, dual-role USB 3.1/3.0/2.0, and USB 2.0 0n-the-Go.
The USB stack also includes role-switching support for root hub and Microchip role-switching hubs.