DFU Functional Descriptor
| Offset | Field | Size | Value | Descripton |
|---|---|---|---|---|
| 0 | bLength | 1 | 09h | Size of this descriptor,in bytes. |
| 1 | bDescriptorType | 1 | 21h | DFU FUNCTIONAL descriptor type. |
| 2 | bmAttributes | 1 | Bit mask | DFU attributes Bit 7……4: reserved Bit 3: device will perform a bus detach-attach sequence when it receives a DFU_DETACH request. The host must not issue a USB Reset. (bitWillDetach) 0 = no 1 = yes Bit 2: device is able to communicate via USB afeter Manifestation phase.(bitManifestationTolerant) 0 = no, must see bus reset 1 = yes Bit1: upload capable(bitCanUpload) 0 = no 1 = yes Bit0: download capable(bitCanDnload) 0 = no 1 = yes |
| 3 | wDetachTimeOut | 2 | Number | Time,in milliseconds, that the device will wait after receipt of the DFU_DETACH request. if this time elapses without a USB reaset, then the device will terminate the Reconfiguration phase and revert back to normal operation . This repreents the maximum time that the device can wait(depending on its timers, etc.).The host may specify a shorter timeout in the DFU_DETACH request. |
| 5 | wTransferSize | 2 | Number | Maximum number of bytes that the device can accept per control-write transaction. |
| 7 | bcdDFUVersion | 2 | BCD | Numeric expression identifying the version of the DFU Specification release. |
