This chip actually comes from Atmel in a state where you do not have to have any special hardware conditions other than that necessary to execute programs. So, you do not need to have the PSEN and Reset pin conditions (which is only applicable depending on package). This only becomes useful if you use FLIP and the BLBJ bit is set (the box has a check mark). If your code does not allow the host to put the chip back into the original bootloader mode and the BLBJ bit is set, then you will have to apply the hardware conditions necessary (depending on the package [low pin count versus high pin count] which is in the datasheet) to reset the chip to boot up in bootloader mode. A safety precaution that I did and proved very helpful while debugging my USB enumeration was that I just left the BLBJ bit not set. This means that once you turn off the power to the chip the chip will automatically boot up in bootloader mode regardless of your program. Hope that helps.