USB Ports
20
SPRUI64E – May 2017 – Revised September 2019
Copyright © 2017–2019, Texas Instruments Incorporated
AM572x Industrial Development Kit (IDK) Evaluation Module (EVM)
Hardware
7
USB Ports
The AM572x IDK EVM contains three USB ports. Two ports are attached to the USB peripherals USB1
and USB2 on the AM572x processor. The third port provides both XDS100V2 JTAG emulation and UART
Console over the USB. This port simplifies the development environment for programmers using
computers that support this capability such as Windows
®
-based computers.
7.1
Processor USB Port 1
Processor port USB1 is implemented only as a USB host (master). It supports both USB2.1 (high speed)
and USB3.0 (super speed) data rates. The connector on the board, J23, is a USB3.0 Standard A-type
connector. The ESD devices implemented on this USB port are the TPD2EUSB30 for the DP and DM
lines and the TPD4E05U06 for the super-speed pairs.
Since processor USB port 1 supports host mode, it has the capability to drive 5.0V power on the VBUS
pin. The TPS2065D load switch is controlled by the USB1_DRVVBUS pin for this purpose.
7.2
Processor USB Port 2
Processor port USB2 is implemented as either USB host (master) or USB device (slave). It supports only
the USB2.1 (high speed and lower) data rates. The connector on the board, J45, is a USB2.1 Micro-AB
connector. The ESD device implemented on this USB port is the TPD4S012.
Since processor USB port 2 supports host mode, it has the capability to drive 5.0V power on the VBUS
pin. The TPS2051 load switch is controlled by the USB2_DRVVBUS pin for this purpose.
The USB2.1 standard defines different ranges of capacitance for the VBUS pin depending on whether it is
host or device. Since this port can do either, the AM572x IDK EVM provides the capability to meet either
requirement. The VBUS pin from the connector contains a 4.7µF capacitor that is appropriate for device
mode operation. When operating in host mode, 2-pin header J50 can be shorted to add 150µF of
additional capacitance to the VBUS pin. The shunt for this header is shown on the schematic as M2. It is
not installed on units when shipped as we expect this port to primarily be used in device mode.
7.3
FTDI USB Port
The FTDI bridge device provides both XDS100V2 JTAG emulation and UART Console over the USB. Its
USB connector is J19 and it is also a USB Micro-AB connector but it only operates in device (slave) mode
with the FTDI bridge device. The ESD device implemented on this USB port to the FTDI bridge is the
TPD2E001. Refer to
for more details on this functionality.
8
PCIe
The AM572x processors contain two lanes of peripheral component interconnect express (PCIe). These
can be implemented either as a single, dual-lane port or as two single-lane ports. The PCIe peripheral can
be configured to either be a Root Complex (master) or an Endpoint (slave). The AM572x IDK EVM only
implements one single-lane port as a Root Complex. The IDK EVM terminates this lane in a single-lane
PCIe female connector that accepts standard PCIe Endpoint cards.
A 2-pin header, J49, is available to provide the 3V3_AUX power separate from the primary 3V3 supply.
This is needed for some cards and PCIe driver configurations. The shunt, shown on the schematic as M1,
should be installed when the board is received since 3V3_AUX will be needed in most cases. Please refer
to the documentation for the card being installed to determine whether this shunt should remain installed.
The PERSTn reset for the connector is driven low coincident with the PORz reset to the AM5728
processor. The PERSTn reset to the connector can also be driven low by a GPIO signal from the
processor. This reset can also be blocked by a GPIO signal from the processor.
A 100-MHz clock is provided separately to both the PCIe peripheral and to the PCIe connector. These
clocks are buffered outputs from the same low-jitter source.
The AM572x IDK EVM is compatible with standard PCIe plug-in cards but not fully compliant with the
PCIe CEM standard. It does not support hot-plug and also does not provide sufficient current on the 3.3V
and 12V pins for all plug-in cards. It is currently limited to about 0.5A on each supply.
