What is a USB device descriptor?
What is a USB device descriptor?
USB devices can only have one device descriptor. The device descriptor includes information such as what USB revision the device complies to, the Product and Vendor IDs used to load the appropriate drivers and the number of possible configurations the device can have.
What is Descriptor List common USB descriptors?
USB descriptors are presented to the host during the enumeration process. These descriptors tell the host what type of device is connected and how to properly communicate with it. There are four types of descriptors: Device Descriptors, Configuration Descriptors, Interface Descriptors, and Endpoint Descriptors.
What is interface descriptor in USB?
The Interface Descriptor (USB_INTERFACE_DESCRIPTOR) defines the collection of endpoints. This interface supports a group of pipes that are suitable for a particular task. Each configuration can have multiple interfaces. The interface can be selected dynamically by the USB Host.
What is USB device enumeration?
USB Enumeration is the process of detecting, identifying and loading drivers for a USB device. This involves a mixture of hardware techniques for detecting something is present and software to identify what has been connected. The purpose of this document is to provide an overview of the mechanics of the process.
What is the device descriptor?
Device Descriptor. The Device Descriptor (USB_DEVICE_DESCRIPTOR) is the root of the descriptor tree and contains basic device information. The unique numbers, idVendor and idProduct, identify the connected device. The Windows operating system uses these numbers to determine which device driver must be loaded.
What is Endpoint Descriptor?
The Endpoint Descriptor (USB_ENDPOINT_DESCRIPTOR) specifies the transfer type, direction, polling interval, and maximum packet size for each endpoint. Endpoint 0 (zero), the default endpoint, is always assumed to be a control endpoint and never has a descriptor.
What is device enumeration?
Identifying all the devices attached to a system and initializing the required routines (drivers) that enable them to function.
How do I bypass device descriptor request failed?
Now that you know what causes this error, here are the six ways to resolve it.
- Quick Fixes for the “Unknown USB Device Descriptor Request Failed” Error.
- Scan Your PC for Hardware Changes.
- Reinstall the USB Drivers.
- Update the Generic USB Hub Drivers.
- Use the Windows Troubleshooting Tool.