AT89C51SND1_06 ATMEL [ATMEL Corporation], AT89C51SND1_06 Datasheet - Page 25

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

Starting the
Application
Request from Host
Answer from Bootloader No answer is returned by the device.
4254C–MP3–03/06
The flow described below allows to start the application directly from the bootloader upon a spe-
cific command reception.
Two options are possible:
•
•
To start the application, the Host sends a DFU_DNLOAD request with the specified application
start type in the data field (3 or 5 bytes).
This request is immediately followed by a second DFU_DNLOAD request with no data field to
start the application with one of the two options.
Command Identifier
Id_write_command
Start the application with a reset pulse generation (using watchdog).
When the device receives this command the watchdog is enabled and the bootloader enters
a waiting loop until the watchdog resets the device.
Be aware that if an external reset chip is used, the reset pulse in output may be wrong and in
this case the reset sequence is not correctly executed.
Start the application without reset
A jump at the address 0000h is used to start the application without reset.
04h
data[0]
03h
SETUP
IN
OUT
SETUP
data[1]
00h
01h
data[2]
address
Jump option (3 or 5 bytes)
DFU_UPLOAD
ZLP
DFU_UPLOAD
data[3]
data[4]
AT89C51SND1
Hardware reset
LJMP address
Description
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