Product manual

Spinpoint M9TU-USB 3.0 Product Manual REV 1.0

USB INTERFACE AND USB COMMANDS

Table 6-7: Standard Request Codes Table 6-8: Descriptor Types

Feature selectors are used when enabling

or setting features, such as remote wakeup,

specific to a device, interface, or endpoint.

The values for the feature selectors are

given in Table 6-9.

If an unsupported or invalid request is made to a USB device, the device responds by returning STALL in

the Data or Status stage of the request. If the device detects the error in the Setup stage, it is preferred that the

device returns STALL at the earlier of the Data or Status stage. Receipt of an unsupported or invalid request

does NOT cause the optional Halt feature on the control pipe to be set. If for any reason, the device becomes

unable to communicate via its Default Control Pipe due to an error condition, the device must be reset to clear

the condition and restart the Default Control Pipe.

6.3.6.3.2 Clear Feature (Request Code 1)

This request is used to clear or disable a specific feature.

Feature selector values in wValue must be appropriate to the recipient. Only device feature selector values may

be used when the recipient is a device, only interface feature selector values may be used when the recipient is an

interface, and only endpoint feature selector values may be used when the recipient is an endpoint.

Refer to Table 6-9 for a definition of which feature selector values are defined for which recipients. A

ClearFeature() request that references a feature that cannot be cleared, that does not exist, or that references an

interface or endpoint that does not exist, will cause the device to respond with a Request Error.

If wLength is non-zero, then the device behavior is not specified.

Default state: Device behavior when this request is received while the device is in the Default state is not

specified.

Address state: This request is valid when the device is in the Address state; references to interfaces or to

endpoints other than endpoint zero shall cause the device to respond with a Request Error.

Configured state: This request is valid when the device is in the Configured state.

Note: The Test_Mode feature cannot be cleared by the ClearFeature() request.

Table 6-9 : Standard Feature Selectors