Specifications

Programmers Guide TH230/TH230+
236
Configuration Descriptor
The configuration descriptor describes information about a specific device configuration.
The descriptor contains a bConfigurationValue field with a value that, when used as a
parameter to the SetConfiguration() request, causes the device to assume the described
configuration.
A USB device has one or more configuration descriptors. Each configuration has one or
more interfaces and each interface has zero or more endpoints.
The whole configuration is transmitted in the following order:
- Configuration Descriptor
- Interface 0 Descriptor (Printer)
- Endpoint 1-2 Descriptors
- Interface 1 Descriptor (DFUX)
- DFUX Functional Descriptor
Offset Field Size Value Description
0 bLength 1 09h Size of this descriptor, in bytes
1 bDescriptorType 1 02h CONFIGURATION descriptor type
2 wTotalLength 2 XXh Size of complete configuration descriptors
(configuration, interface, endpoint, class- or
vendor-specific) in bytes
4 bNumInterfaces 1 02h Number of interfaces supported by this config.
5 bConfigurationValue 1 01h Configuration value (for SET_CONFIGURATION)
6 iConfiguration 1 00h Index of string descriptor (not used)
7 bmAttributes 1 E0h Configuration characteristics
Bit 7: Reserved (set to one)
Bit 6: Self-powered
Bit 5: Remote Wakup
Bit 4..0: Reserved (reset to zero)
8 bMaxPower 1 00h Maximum power consumption from the bus