9

7618C–AVR–07/08

4.6.1

Request From Host

4.6.1.1

Write Command

The write command is 6 bytes long. In order to meet with the USB specification of the Control

type transfers, the write command is completed with 26 (= 32 - 6) non-significant bytes. The total

length of the command is then 32 bytes, which is the length of the Default Control Endpoint.

4.6.1.2

Firmware

The firmware can now be downloaded to the device. In order to be in accordance with the Flash

page size (128 bytes), X non-significant bytes are added before the first byte to program. The X

number is calculated to align the beginning of the firmware with the Flash page. X =

start_address [32]. For example, if the start address is 00AFh (175d), X = 175 [32] = 15.

4.6.1.3

DFU Suffix

The DFU suffix of 16 bytes is added just after the last byte to program. This suffix is reserved for

future use.

-10

idVendor

2

ID

The vendor ID associated with this file. Either FFFFh or

must match device’s vendor ID

-12

idProduct

2

ID

The product ID associated with this file. Either FFFFh or

must match the device’s product ID

-14

bcdDevice

2

BCD

The release number of the device associated with this

file. Either FFFFh or a BCD firmware release or version

number

Offset

Field

Size

Value

Description

bmRequestType

bRequest

wValue

wIndex

wLength

Data

0010 0001b

DFU_DNLOAD (1)

wBlock

Interface (4)

Length

Firmware

Command Identifier

data[0]

data[1]

data[2]

data[3]

data[4]

Description

Id_prog_start

01h

00h

start_address

end_address

Init FLASH programming

01h

Init EEPROM programming