Renesas mPD720231, Руководство пользователя

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PD720231 4. USB Descriptor Information
R19UH0094EJ0100 Rev 1.00 Page 20 of 30
Mar 1, 2013
4.7
Device Qualifier Descriptor (High-/Full-speed only)
A device qualifier descriptor describes general information about a high-speed capable device that would
change if the device were operating at the other speed. For example, if the device is currently operating at
full-speed, the device qualifier returns information about how it would operate at high-speed and vice-versa.
Offset Field Size Value Description
0 bLength 1 0Ah Size of descriptor
1 bDescriptorType 1 06h Device qualifier descriptor type
2 bcdUSB 2 0210h USB specification version number (BCD)
4 bDeviceClass 1 00h Class Code
5 bDeviceSubClass 1 00h SubClass Code
6 bDeviceProtocol 1 00h Protocol Code
7 bMaxPacketSize0 1 40h Maximum packet size for this speed (64 bytes)
8 bNumConfigurations 1 01h Number of this speed configuration
9 Reserved 1 00h Reserved for future use.
4.8
Other_Speed_Configuration Descriptor (High-/Full-speed only)
An other_speed_configuration descriptor describes a configuration of a high-speed capable device if it were
operating at its other possible speed. The structure of the other_speed_configuration is identical to a
configuration descriptor. When the host requests the other_speed_configuration descriptor, all related
interface and endpoint descriptors are returned.
Offset Field Size Value Description
0 bLength 1 09h Size of descriptor
1 bDescriptorType 1 07h Other_speed_configuration descriptor type
2 wTotalLength 2 0020h Total length of data returned for this configuration.
4 bNumInterfaces 1 01h Number of interfaces supported by this speed
configuration
5 bConfigurationValue 1 01h Value to use to select configuration
6 iConfiguration 1 00h Index of string descriptor describing configuration.
7 bmAttributes 1 C0h Configuration characteristics
8 bMaxPower 1 32h Maximum power consumption of the USB device from
the bus in this configuration when the device is fully
operational.