Hello mks,

I think you are talking about FlasherARM, not J-Flash.

To your questions:

>>1) the device is powered by USB, then what does RS232 do?
The RS232 interface of FlasherARM is used for two purposes:
a) To control FlasherARM operation via Handshake lines: 3 lines on the serial interface are used.
b) For terminal communication with FlasherARM via RS232, using the ASCII command interface.

>>2) in our case, we need to download Atmel boot strap first then download the firmware. Will stand alone mode work in this case?
I am not sure what you mean. If you mean that you have 2 data files to be downloaded into the target then you will need 2 FlasherARM when
operating in stand-alone mode because FlasherARM can only be configured for one target, using one file to download, for the same time.

>>3) Will stand alone mode give user feedback if the download is successful or not?
Progress and result of an operation is indicated by Flasher ARM’s LEDs, they indicate if an operation is in progress / was successful / failed.

Best regards,
Alex