Hi Jun,
You mentioned is about the second bootloader.
Is it possible to download firmware via on-chip ROM boolotader over I2C interface?
If the answer is yes, could you tell me how to do it?
Currently, I know a way to download firmware via UART.
1. Set MCU to boot into ISP mode.
2. Use the tool FlashMagic to download MCU firmware via UART.
BR,
carter
BR,
carter