at89c5131a ATMEL Corporation, at89c5131a Datasheet - Page 16

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

Device State
DFU_ABORT request
Programming the Flash or
EEPROM Data
16
AT89C5131A USB Bootloader
This request solicits a report about the state of the device. The state reported is the cur-
rent state of the device with no change in state upon transmission of the response. The
values specified in the bState field are identical to those reported in DFU_GETSTATUS.
The DFU_ABORT request enables the device to exit from certain states and return to
the DFU_IDLE state. The device sets the OK status on receipt of this request. For more
information, see the corresponding state transition summary.
The firmware image is downloaded via control-write transfers initiated by the
DFU_DNLOAD class-specific request. The host sends between bMaxPacketSize0 and
wTransferSize bytes to the device in a control-write transfer. Following each down-
loaded block, the host solicits the device status with the DFU_GETSTATUS request.
As described in the USB DFU Specification, "Firmware images for specific devices are,
by definition, vendor specific. It is therefore required that target addresses, record sizes,
and all other information relative to supporting an upgrade are encapsulated within the
firmware image file. It is the responsibility of the device manufacturer and the firmware
developer to ensure that their devices can consume these encapsulated data. With the
exception of the DFU file suffix, the content of the firmware image file is irrelevant to the
host."
Firmware image:
•
•
•
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Table 9. DFU File Suffix
bmRequestType
Offset
bmRequestType
-10
32 bytes: Command
X bytes: X is the number of byte (00h) added before the first significative byte of the
firmware. 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 firmware
The DFU Suffix on 16 Bytes.
-0
-4
-5
-8
1010 0001b
1010 0001b
Field
dwCRC
bLength
ucDfuSignature
bcdDFU
idVendor
DFU_GETSTATE (5)
DFU_ABORT (6)
bRequest
bRequest
Size
4
1
3
2
2
Number
Value
5 : 44h
6 : 46h
7 : 55h
0100h
BCD
16
ID
wValue
wValue
Zero
Zero
Description
The CRC of the entire file, excluding dwCRC
The length of this DFU suffix including dwCRC
The unique DFU signature field
DFU specification number
The vendor ID associated with this file. Either FFFFh
or must match device’s vendor ID
Interface (4)
Interface (4)
wIndex
wIndex
wLength
wLength
1
0
4287C–USB–11/04
Data
Data
State
None