AT89C5131A View Datasheet(PDF) - Atmel Corporation

Part Name

Description

Manufacturer

AT89C5131A

USB Microcontrollers

Atmel Corporation 

Request From Host

Offset Field

-12 idProduct

-14 bcdDevice

Size

2

2

Value

ID

BCD

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

bmRequestType

0010 0001b

bRequest

DFU_DNLOAD (1)

wValue

wBlock

wIndex

wLength

Interface (4) Length

Data

Firmware

Write Command

Firmware

DFU Suffix

Command

Identifier

Id_prog_start

01h

data[0]

00h

01h

data[1] data[2]

start_address

data[3] data[4]

end_address

Description

Init FLASH programming

Init EEPROM

programming

The write command is 6 bytes long. In order to reach 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.

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.

18 AT89C5131A USB Bootloader

4287E–USB–04/08

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