Nvidia TEGRA DG-04927-001_V01 - Manual (Page 25)

Tegra 200 Series Developer Board User Guide
DG-04927-001_v01 Advance Information – Subject to Change 25
NVIDIA CONFIDENTIAL
4.5.1 Force Recovery
The Tegra 250 requires USB1 to be available as a Device for Force Recovery mode which is used to download new firmware.
This is shown in Figure 12 where a USB Mini B connector is available to connect to a Host system. Force Recovery mode is
entered by keeping the FORCE_RECOVERY pin low when the system is first powered up (until SYS_RESET_N goes high.
This is accomplished by pressing the momentary push button shown during power-on.
Figure 12 Force Recovery Connections
4.5.2 ULPI
The Tegra 250 optionally supports ULPI (UMTI+ Low Pin Interface) as an option to connect to external USB PHYs, or other
compatible devices.
ƒ 12 bit interface including ULPI_CLK, ULPI_DIR, ULPI_NXT, ULPI_STP and ULPI_DAT[7:0]
ƒ Operates from 60 MHz clock
ƒ 8-bit SDR data interface - 4-bit DDR data I/F not supported
Figure 13 shows the Tegra 250 interfacing with an external ULPI-USB PHY. The USB PHY can be used to interface to a
compatible Baseband, a USB Hub, etc.
Figure 13. Example ULPI connection to External SMSC USB3317 USB PHY