Introduction
USB driver support in Windows is documented in the current WDK in "USB." See also the FAQs, white papers and presentations on USB - Architecture and Driver Support.

If you are looking for software support for USB 2.0 for Windows:

? For Windows XP, support is provided in the Windows XP Service Pack release.
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? For Windows 2000, support is provided in Windows 2000 Service Pack 4.
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? For Windows Server 2003, support for USB 2.0 is built in.

USB Architecture in Windows
The following sections describe the USB driver stack on Windows XP and compare it to Windows 2000.

Windows XP USB Driver Stack
Figure 1 illustrates the WDM driver stack that is created in Windows XP for two USB devices, one composite and one non-composite. The composite device has two interfaces, each of which is driven by a separate client driver.

Click to view full-size image.

The figure illustrates the functionality of the port driver and the associated mini-ports that work with Windows XP. Windows XP natively supports Usbuhci.sys and Usbohci.sys. Windows Server 2003 and Windows XP will allow for a new mini-port called Usbehci.sys, allowing native support for specific USB Enhanced Host Controllers.

A host controller-specific coinstaller (Hccoin.dll) will also be provided to synchronize interaction between the Enhanced Host Controller and companion host controllers (if present).

Windows 2000 USB Driver Stack
The Windows 2000 driver stack for USB is different from Windows XP. To support USB 2.0 on Windows 2000, a parallel (new) driver stack is needed. This driver stack will consist of Usbport.sys, Usbhub20.sys and Usbehci.sys. A host controller-specific coinstaller (Hccoin.dll) will also be provided to ensure proper Windows Update installation in the Windows 2000 scenario.

Microsoft will not provide USB 2.0 driver support on Windows 9x or earlier Windows operating systems.

For additional architectural details on the Windows XP and Windows 2000 USB driver stacks, please refer to the Windows Driver Kit (WDK).

Microsoft Supported Host Controllers
Microsoft is planning a split approach to supporting USB 2.0. The initial Windows XP USB 2.0 release (delivered through Windows Update and OEM preinstallation on new systems) supports only the following hardware IDs, belonging to the NEC USB 2.0 EHCI controller:

? PCI\VEN_1033&DEV_00E0&REV_01
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? PCI\VEN_1033&DEV_00E0&REV_02
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The NEC USB 2.0 host controller is the first EHCI controller to be certified by the USB EHCI testing body, and has been the only USB 2.0 controller available in the market during the initial Windows development effort for USB 2.0. Microsoft is working closely with other EHCI silicon vendors and will provide support in the future for USB 2.0 EHCI Host Controllers that meet the following criteria:

? The USB 2.0 host controller must be compatible with the Enhanced Host Controller specification revision 0.96 and later.
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? The USB 2.0 host controller must be compliant with all related USB controller requirements listed in the latest Window Logo Program (version 2.0), available on the Windows Logo Program Web site.
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? The USB 2.0 host controller must be compatible with the existing Windows Server 2003 EHCI mini-port driver. Incompatibilities must be investigated by the silicon vendor and reported to Microsoft, if they are believed to be driver-related issues.
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? The USB host controller may or may not contain companion controllers. If no companion host controllers are present, Microsoft requires the host silicon expose a self-powered USB 2.0 hub (with a Transaction Translator) hanging downstream of every port of the USB 2.0 controller. All companion controllers must be the same and must be compatible with the OHCI or UHCI specifications.
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? Host controllers integrated into the South Bridge must decouple the PCI bus reset from a USB bus reset. The USB host controller must not issue a USB bus reset on a transition from S3 to S0 or from S1 to S0. For additional details on S-state mappings, please refer to the Windows XP WDK.
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? The hardware IDs for the companion host controllers must be unique and never have been used on a stand-alone host controller. This will ensure that Windows can identify a host controller as a companion host controller by checking the hardware ID.
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? Microsoft should receive production quality hardware in time for testing on Windows Server 2003. At least six systems/cards must be available to Microsoft within the time period specified in the following item.
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? Microsoft must receive the hardware IDs and samples of the host controllers no later than March 1, 2002. Hardware IDs for EHCI controllers received later may not be accepted for Windows Server 2003.
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? The Enhanced Host Controller must be compatible with the HCT 11 release that accompanies the Windows Server 2003 Release Candidate 1 (RC 1) release.
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Microsoft reserves the right to append, remove, or modify the conditions listed above based on the Windows Server 2003 schedule.

Support for Windows 2000 is not planned for Service Pack 3. However, USB 2.0 support will be made available to Windows 2000 customers as a driver package available on Windows Update. System manufacturers may receive permissions to redistribute the USB 2.0 driver package for Windows 2000. Details will be made available on the USB Technology page when plans are complete.

WHQL Testing
The Windows Hardware Quality Labs has released Quick Fix Engineering package 4 (QFE 4) for the HCT 10.0 test kit. This test kit is essential for testing the quality of hardware devices on Windows XP systems.

QFE 4 for HCT 10.0 includes tests to ensure that USB 2.0 Hi-Speed devices and USB EHCI host controllers work properly with Windows XP. Please note that USB 2.0 compliant hubs will not be eligible for receiving the "Designed for Microsoft Windows" logo with QFE 4. The tests to validate USB 2.0 hub quality are still under development and will be available in the HCT 11.0 release accompanying Windows Server 2003.

HCT 11.0 will also contain additional new tests for validating USB 2.0 devices. Vendors are requested to download the HCT 11 RC that will be published in conjunction with the Windows Server 2003 RC 1 release and use this HCT version to validate device integrity.

The Windows XP HCT 10.0 QFE 4 package updates the USB tests listed below to test devices that comply with the USB 2.0 high- speed device specification. USB 2.0 high-speed devices that pass Windows Logo Program testing with the Windows XP HCT 10.0 (with QFE 4 installed) can qualify to display the "Designed for Microsoft Windows" logo for hardware.

USB Device testing:

? USB 1.1 Specification Compliance
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? USB Address Description
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? USB Device Control Requests
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? USB Device Framework
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? USB Enumeration Stress
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? USB HIDView
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? USB Selective Suspend
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? USB Manual Interoperability

USB Controller Testing:

? USB Host Controller Compliance
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To obtain additional details on testing requirements and procedures, please review the USB 2.0 testing instructions provided in the HCT 10.0 + QFE 4 package available on the WHQL Web site.

For additional issues or questions, please contact WHQL though the appropriate e-mail aliases identified on the WHQL Web site.