AN249 Silicon_Laboratories, AN249 Datasheet - Page 19

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

}; //end of String1Desc
The index values to USB-specification standard descriptive texts such as the Product String, the Manufacturer
String, and the Serial string are defined in the Device Descriptor. For instance, the firmware template defines the
Product String index as “0x02” in the Device Descriptor. At any point after the host retrieves the Device Descriptor,
the host can retrieve the Product String by making a standard Get Descriptor request for a String Descriptor of
index “0x02”. When the firmware template receives this request, it returns the value of the string held in memory
addressed in indexed element “0x02” of the String Descriptor Table.
5.4.8. Report Descriptor
By default, the Report Descriptor declaration of the firmware template is left blank. The contents of this descriptor
depend on device requirements. The next two sections provide examples of how the Report Descriptor can look
and how Reports can be structured.
'T', 0,
'O', 0,
'R', 0,
'I', 0,
'E', 0,
'S', 0
Rev. 0.2
AN249
19