at89c5131a ATMEL Corporation, at89c5131a Datasheet - Page 18

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

Figure 6. Example of Firmware Download Zero Length DFU_DNLOAD Request
Answers from Bootloader
18
AT89C5131A USB Bootloader
SETUP
OUT
OUT
OUT
OUT
IN
The Host sends a DFU_DNLOAD request with the wLength field cleared to 0 to the
device to indicate that it has completed transferring the firmware image file. This is the
final payload packet of a download operation.
This operation should be preceded by a Long Jump address specification using the cor-
responding Flash command.
After each program request, the Host can request the device state and status by send-
ing a DFU_GETSTATUS message.
If the device status indicates an error, the host can send a DFU_CLRSTATUS request
to the device.
DFU_DNLOAD
Prog_Start + (EP0 fifo length - 6) x 00h
X offset bytes + Firmware Packet 1
Firmware Packet 2
Firmware Packet n + DFU suffix
ZLP
4287C–USB–11/04