at89c5131a ATMEL Corporation, at89c5131a Datasheet - Page 17

• Manufacturer Part Number: at89c5131a
• Description: Usb Microcontrollers
• Manufacturer: ATMEL Corporation

Request From Host
Write Command
Firmware
DFU Suffix
4287C–USB–11/04
The write command is 6 bytes long. In order to reach the USB specification of the Con-
trol 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.
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.
The DFU suffix of 16 bytes are added just after the last byte to program. This suffix is
reserved for future use.
Offset
bmRequestType
-12
-14
Id_prog_start
Command
Identifier
0010 0001b
01h
Field
idProduct
bcdDevice
data[0]
00h
01h
DFU_DNLOAD (1)
bRequest
Size
data[1]
2
2
AT89C5131A USB Bootloader
start_address
Value
BCD
data[2]
ID
wValue
wBlock
Description
The product ID associated with this file. Either FFFFf
or must match the device’s product ID
The release number of the device associated with
this file. Either FFFFh or a BCD firmware release or
version number
data[3]
end_address
Interface (4)
wIndex
data[4]
wLength
Init FLASH programming
Length
Description
Init EEPROM
programming
Firmware
Data
17