AT89C51SND1_06 ATMEL [ATMEL Corporation], AT89C51SND1_06 Datasheet - Page 17

• Manufacturer Part Number: AT89C51SND1_06
• Description: USB Microcontrollers
• Manufacturer: ATMEL [ATMEL Corporation]

Device State
DFU_ABORT Request
Programming the
Flash
4254C–MP3–03/06
This request solicits a report about the state of the device. The state reported is the current 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 downloaded 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 defini-
tion, 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:
•
•
•
•
Table 16. DFU File Suffix
bmRequestType
bmRequestType
Offset
- 10
- 0
- 4
- 5
- 8
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
1010 0001b
1010 0001b
Field
dwCRC
bLength
ucDfuSignature
bcdDFU
idVendor
DFU_ABORT (6)
DFU_GETSTATE (5)
bRequest
bRequest
Size
4
1
3
2
2
wValue
Zero
Number The CRC of the entire file, excluding dwCRC
5: 44h
6: 46h
7: 55h
0100h
Value
BCD
wValue
16
ID
Zero
Description
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)
wIndex
Interface (4)
wIndex
AT89C51SND1
wLength
wLength
0
1
None
State
Data
Data
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