Jetson AGX Xavier Series Product
DG-09840-001_v2.5 | 116
Chapter 15.
Debug and Strapping
This chapter covers the interfaces that are provided for debug & development as well as
covering SoC pin strapping and boundary scan.
15.1
USB Recovery Mode
USB Recovery mode provides an alternate boot device (USB). In this mode, the system is
connected to a host system and boots over USB. This is used when a new image needs to be
flashed, or for debug purposes. To enter USB recovery mode, the
FORCE_RECOVERY_N
pin is
held low when the system is powered on.
FORCE_RECOVERY_N
is the SoC RCM0 strap.
Recovery mode can operate in either USB 2.0 or USB 2.0 + USB 3.1 modes. Recovery mode
using USB 2.0 is from interface USB0_N/P only. No other signals are required or supported for
entering Force Recovery mode. Neither VBUS or ID detection is needed. As long as the force
recovery strap is held low coming out of reset, Jetson Xavier NX will configure USB0 as a
device and enter recovery mode.
For USB 3.1 recovery mode, the system will first enter USB 2.0 recovery mode using
USB0_N/P
and then software configures the transition to use the USB 3.1 interface for the remainder of
the flashing process. The USB 3.1 recovery mode interface must come from the
UPHY_TX1/RX1_P/N
pins. See the “USB” section (Section 7.1) for an example connection figures
that shows USB0 and
PEX_TX1/RX1_PN
connected to either a USB Type C connector or a USB
Micro AB SS connector. In the example, a 5V power switch output connects to the VBUS pin on
the connector. This supply is disabled by default in our reference design, so there is no
contention with the 5V from the host system VBUS supply. If the supply on the Xavier system is
present and enabled, the VBUS pin should not be connected from the host (special cable with
VBUS disconnected).