VERSION 1.9
J120 (38198-X)
UART 0 / UART 2 (J7) - rev 2 to 5
This is the configuration for the J120 rev 2 with a serial number > 2020. All 4 pins are passed through a bi-
directional level converter with 3.3V level outputs (TXB0104PWR) and through 33 Ohm series resistors (in a
tiny 0804 size resistor array). To limit the power dissipation in the resistor array, it is advised to sink or source
a maximum current of 1 mA.
UART 0 (J7) - rev 6
This is the configuration for the J120 rev 6. 2 pins are passed through a bi-directional level converter with
3.3V level outputs (TXB0104PWR) and through 33 Ohm series resistors (in a tiny 0804 size resistor array). To
limit the power dissipation in the resistor array, it is advised to sink or source a maximum current of 1 mA. Pin
4 and 5 provide the programming interface for the watchdog MCU (STM42F042).
UART 0 / UART 2 (J7) - rev 7
This is the configuration for the J120 rev 7. All 4 pins are passed through a bi-directional level converter with
3.3V level outputs (TXB0104PWR) and through 33 Ohm series resistors (in a tiny 0804 size resistor array). To
limit the power dissipation in the resistor array, it is advised to sink or source a maximum current of 1 mA. Pin
4 and 5 have the dual function to flash the watchdog MCU.
If the tunnelling of the UART0 port causes difficulties in a particular use case, the J120 can be reconfigured so
that the MCU is bypassed and a direct connection to the UART0 port of the TX1 and TX2 is provided. Please
check appendix A for details on the watchdog MCU.
Pin
Function
Jetson TX1
GPIO
Description
1
5V
-
-
5V power output
2
UART0_TXD
H12
GPIO3_PU.00
UART 0 console port (3.3V TTL level): transmit data output
3
UART0_RXD
G12
GPIO3_PU.01
UART 0 console port (3.3V TTL level): receive data input
4
UART2_TXD
B16
-
UART 2 console port (3.3V TTL level): transmit data output
5
UART2_RXD
B15
-
UART 2 console port (3.3V TTL level): receive data output
6
GND
-
-
Ground
Pin
Function
Jetson TX1
GPIO
Description
1
5V
-
-
5V power output (3.3V if only the MCU is powered)
2
UART0_TXD
-
-
UART 0 console port (3.3V TTL level): transmit data output
- tunnelled though the watchdog MCU
3
UART0_RXD
-
-
UART 0 console port (3.3V TTL level): receive data input -
tunnelled through the watchdog
4
SWCLK
-
-
port to flash watchdog MCU
5
SWDIO
-
-
port to flash watchdog MCU
6
GND
-
-
Ground
AUVIDEA GMBH
TECHNICAL REFERENCE MANUAL
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