Hi,
It is very glad to use chip QN9021.Now i use Uart to connect its Bootloader, i met some difficulties.
1.as the datasheet shows.

So before connected ,what my UART baud rate shouled be?
2. ISP PDU has CRC(2 bytes),but i don't know how to caculate?

Could you help me with it ? or provide a example. such as input 0x01,0x02,and then out put is 0xaabb.or i will preciate
if you can provide a C language example.
3.when i want to download a appliacation to flash? Which Steps is necessary?
as the datasheet shows:

Thanks for your reading.
I am waiting for your replay.