Special instructions for using the JTAG interface

There are four JTAG programming pins on the XBee/XBee-PRO Zigbee RF Module through which firmware can be loaded onto the EM357 processor. Three of these pins are also connected to a second pin on the device and are used for separate functions. The following table indicates the JTAG signal name, the primary connection pin on the device, the secondary connection pin, and the secondary signal name.

CAUTION! Do not load the secondary pins with circuitry that might interfere with JTAG programming (for example, an LED tied directly to the ASSOCIATE / DIO5 line). Any loading circuitry should be buffered to avoid conflicts (for example, connecting ASSOCIATE / DIO5 to the gate of a MOSFET which drives the LED).

JTAG pin name Primary XBee pin Secondary XBee pin Secondary pin name
JTCK 18 N/A N/A
JTDO 19 26 ON / SLEEP / DIO9
JTDI 20 28 ASSOCIATE / DIO5
JTMS 21 5 DIO12