AN249 Silicon_Laboratories, AN249 Datasheet - Page 34

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

AN249
}; //end of DeviceDesc
When a device gets connected to the host system for the first time, the system saves a record that links the
device’s Vendor ID and Product ID to the drivers the system determines it should use for communication. If an
‘F320 is loaded with the USB mouse example and connected to the host system, the system determines that the
USB mouse drivers should be used to interact with attached devices matching this Product and Vendor ID. Later, if
the ‘F320 is loaded with HID firmware for this example but with the same Product and Vendor ID, the system
expects that the attached device is a USB mouse and tries to communicate with it with those drivers. Host
application software will not be able to communicate with the device. In this Device descriptor, the firmware has
been given a distinct Product ID.
Manufacturer and Product strings have been added to this design so that some information appears on-screen
when the device is attached.
8.2.1.2. Configuration Descriptor
This example contains one more descriptor, than the USB mouse example because the design uses an OUT
endpoint. The last 7 bytes added to the total length include this descriptor.
This amount of current will be sufficient to supply the ‘F320 with enough current to function properly.
8.2.1.3. Interface, IN Endpoint, and OUT Endpoint Descriptors
No changes to the firmware template need to be made to implement this design other than modifying the Endpoint
Sizes to be at least as large as the largest Reports.
34
0xC410,
0x0002,
0x0000,
0x01,
0x02,
0x00,
0x01
0x0002,
0x01,
0x02,
0x09,
0x02,
0x2900,
0x01,
0x01,
0x00,
0x80,
0x20
0x2900,
0x20
// idProduct
// iManufacturer
// iProduct
// Length
// Type
// Totallength (= 9+9+9+7+7)
// NumInterfaces
// bConfigurationValue
// iConfiguration
// bmAttributes
// MaxPower (in 2 mA units)
// Totallength (= 9+9+9+7+7)
// MaxPower (in 2 mA units)
// idVendor
// idProduct
// bcdDevice
// iManufacturer
// iProduct
// iSerialNumber
// bNumConfigurations
Rev. 0.2