Tegra 200 Series Developer Board User Guide

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.

ƒ12 bit interface including ULPI_CLK, ULPI_DIR, ULPI_NXT, ULPI_STP and ULPI_DAT[7:0]

ƒOperates from 60 MHz clock

ƒ8-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

DG-04927-001_v01

Advance Information – Subject to Change

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