|Alpha : Visual Tour Switching Between Bootloader and Target Firmware|
The answer is that the target firmware must have some way of jumping back to the bootloader code (which is still in place, close to the top of the PIC processor's Flash program memory) at the appropriate time.
YOU, the developer, must decide what "at the appropriate time" means. It could be a press of some secret button, or a special command from the PC, or something else you decide.
Whatever it is, it must be something that your end user can easily do without special equipment, yet it must be something he would not ordinarily do, so the device doesn't suddenly switch over to bootloader mode during normal use. (Customers don't like surprises like that!)
|1 2 3 4 5 6 7 8 9 10 11|