Debug and Strapping
Jetson AGX Xavier Series Product
DG-09840-001_v2.5 | 121
15.5
Safety MCU JAXi Only
Jetson JAXi Xavier adds support for a safety MCU in the system for designs that require this.
The following connections are intended to use with a safety MCU.
SPI2
VM_I2C (Voltage Monitor I2C)
VM_INT_N (Voltage Monitor Interrupt)
GPIO31 (SAFESTATE)
GPIO12 (BOOT_CHAIN_SELECT strap)
NC_O3 (TEMP_THERM_OUT
EQOS / RGMII (Ethernet)
The pin descriptions for several of the signals involved with a safety MCU design are shown in
the following table. For SPI and RGMII (Ethernet) pin descriptions, see the respective sections
earlier in this design guide.
Table 15-5.
Safety MCU Related Partial Pin Descriptions
Pin # Module Pin
Name
SoC Signal
Usage/Description
Usage on NVIDIA
Carrier Board
Direction
Pin Type
L44
VM_I2C_SCK
na
JAXi only: Connects to safety MCU on carrier
board if implemented. Routed on module to
mux with PWR_I2C. Mux select connected to
SoC reset. Output of mux controls on-
module voltage monitors. VM_I2C controls
when reset is active (low).
Unused
Bidir
Open Drain, 3.3V
L45
VM_I2C_DAT
na
Bidir
Open Drain, 3.3V
L47
VM_INT_N
na
Interrupt from on-module voltage monitors.
Connects to safety MCU if implemented.
Output
Open Drain, 3.3V
H60
GPIO31
SAFE_STATE
GPIO. For JAXi only, routed to the safety
MCU.
Micro SD / UFS Card
Socket (UFS Detect)
Bidir
CMOS – 1.8V
E10
GPIO12
(BOOT_CHAIN_
SELECT strap)
SOC_GPIO33
JAXi only, used as a strap at power-on to
select from two boot chains. Driven by the
Safety MCU if implemented.
M.2 Key E Connector
(M2 Wake AP)
Bidir
CMOS – 1.8V
G59
NC_03 (TEMP_
THERM_OUT)
−
Connects to on-module temperature sensor
THERM* output. 10kΩ pullup to 1.8V on
module.
Unused
Output
Open Drain, 1.8V
Notes:
1.
In the Type/Dir column, Output is from Jetson AGX Xavier. Input is to Jetson AGX Xavier. Bidir is for Bidirectional signals.
