
USART bootloader
AN2662
Doc ID 14156 Rev 1
Figure 19.
Write Unprotect command: host side
1.
WPUN = Write Unprotect.
Figure 20.
Write Unprotect command: device side
1.
WPUN = Write Unprotect.
Wait for ACK
or NACK
Wait for ACK
or NACK
End of WPUN
(1)
NACK
ACK
ai14647
Send 0x73+0x8C
Start WPUN
(1)
NACK
ACK
ROP active
Remove the protection for the
entire Flash memory
No
Yes
ai14648b
Start WPUN
(1)
Received bytes =
0x73+0x8C?
Send ACK byte
Send NACK byte
End of WPUN
(1)
No
Yes
Send ACK byte
Generate system reset