Answer

The minimum pins required to program the EM3xx device are VCC, GND, SWCLK, SWDIO (PC4), and nRESET.  On the packet trace port connector, these are pins 1, 5, 6, 7, and 8 respectively, This allows for serial wire programming of the EM3xx device.  For full debug and packet trace functionality, the full packet trace port set of connections should be used.  Please refer to the EM3xx reference designs (ZigBee Featured Reference Designs) for more details on this packet trace connector interface.