Figure 1 below shows how to connect the JTAG ICE probe to the
AVR Butterfly.
Note: The JTAG connector must be mounted on the back-side of the AVR Butterfly
The JTAG connector is used for the ATmega169 built in JTAG
interface. The pinout of the connector is shown in Figure 2 and is compliant with the pin out of the JTAG ICE
available from Atmel. Connecting a JTAG ICE to this connector allows On-chip Debugging of
the ATmega169.
More information about the JTAG ICE and the On-chip
Debugging can be found in the AVR JTAG ICE User Guide, which is available at the Atmel web
site, http://www.atmel.com/.
Note: Pin 7, NC(VCC) is the Vsupply pin for the JTAG. This pin is not connected because the
JTAG would draw power from the battery on the AVR Butterfly. Pin 8, NC(BS2) and the pin 10,
GND(XTAL1) can be modified serve as the BS2 and XTAL1 pin during High-voltage Parallel
Programming. For more details see 3.2.2 High-voltage Parallel Programming.
Note: It is highly recommended to apply external power (3,1 4,5V), when using the JTAG to save
the battery. See External power on page 14 for how to connect external power. Make sure to
disable the OCD-fuse after a debugging session, due to power consumption. The OCD-fuse will
be disabled if pressing on the "Stop Debugging" button in AvrStudio4, before disconnecting
the JTAG ICE probe from the AVR Butterfly.
External power can be applied at pin 9 and 10 at both PORTB
and PORTD, see Figure 6 for the pinout.
If the JTAG are not in use, the four JTAG pins can be used
as input for the ADC channels ADC[4:7]. See the ATmega169 datasheet for more information,
available from http://www.atmel.com.