USB DFU bootloader requests

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USB DFU bootloader requests

USB DFU bootloader supports the DFU protocol and requests compliant with the “Universal

Serial Bus Device Upgrade Specification for Device Firmware Upgrade” Version 1.1, Aug 5,

2004. For more details concerning these requests, refer to the specification.

Table 2 and Table 3 enumerate the DFU Class-Specific requests and their parameters.

Table 2. DFU class requests

Note:

The Detach request is not meaningful in the case of the bootloader. The bootloader is

started by a system reset depending on the boot mode configuration settings, which means

that no other application is running at this time.

Request

Request code

Request description

DFU_DETACH

0x00

Requests the device to leave DFU mode and enter the

application.

DFU_DNLOAD

0x01

Requests data transfer from Host to the device in order to

load them into device internal Flash. Includes also erase

commands.

DFU_UPLOAD

0x02

Requests data transfer from device to Host in order to

load content of device internal Flash into a Host file.

DFU_GETSTATUS

0x03

Requests device to send status report to the Host

(including status resulting from the last request execution

and the state the device will enter immediately after this

request).

DFU_CLRSTATUS

0x04

Requests device to clear error status and move to next

step.

DFU_GETSTATE

0x05

Requests the device to send only the state it will enter

immediately after this request.

DFU_ABORT

0x06

Requests device to exit the current state/operation and

enter idle state immediately.

Table 3. Summary of DFU class-specific requests

bmRequest

bRequest

wValue

wIndex

wLength

Data

00100001b

DFU_DETACH

wTimeout

Interface Zero

None

00100001b

DFU_DNLOAD

wBlockNum

Interface Length

Firmware

10100001b

DFU_UPLOAD

Zero

Interface Length

Firmware

00100001b

DFU_GETSTATUS Zero

Interface 6

Status

00100001b

DFU_CLRSTATUS

Zero

Interface Zero

None

00100001b

DFU_GETSTATE

Zero

Interface 1

State

00100001b

DFU_ABORT

Zero

Interface Zero

None