AN249 Silicon_Laboratories, AN249 Datasheet - Page 27

• Manufacturer Part Number: AN249
• Description: Human Interface Device Tutorial
• Manufacturer: Silicon_Laboratories

};
This example declares a string describing the hardware manufacturer at string table index 1. This item will allow
the host to retrieve that string.
This example also declares a string describing the product at string table index 2.
7.2.2. Configuration Descriptor
This item was calculated by adding together the lengths of the configuration descriptor (9) and all of the other
descriptors associated with this particular configuration, specifically the Interface Descriptor (9), one IN Endpoint
descriptor (7), and the HID Descriptor(9).
This item tells the host that the device will require 64 mA to function properly. This should be enough current to
supply the microcontroller.
7.2.3. Interface Descriptor
{ // endpoint_descriptor hid_endpoint_in_descriptor
};
This item has been set to the Boot Interface subclass, which is one of the defined HID subclass types. The Boot
Interface is a standard transfer mode that can be used by a system’s BIOS at boot time. This device must tell the
firmware that it is compatible with the Boot Interface subclass in order to be recognized as a USB Mouse.
0x01,
0x02,
0x09,
0x02,
0x2200,
0x01,
0x01,
0x00,
0x80,
0x20
0x2200,
0x20
0x09,
0x04,
0x00,
0x00,
0x01,
0x03,
0x01,
0x02,
0x00
0x01,
// iManufacturer
// iProduct
// Length
// Type
// Totallength (= 9+9+9+7)
// NumInterfaces
// bConfigurationValue
// iConfiguration
// bmAttributes
// MaxPower (in 2 mA units)
// Totallength (= 9+9+9+7)
// MaxPower (in 2 mA units)
// bLength
// bDescriptorType
// bInterfaceNumber
// bAlternateSetting
// bNumEndpoints
// bInterfaceClass (3 = HID)
// bInterfaceSubClass
// bInterfaceProcotol
// iInterface
// bInterfaceSubClass
//end of DeviceDesc
Rev. 0.2
AN249
27