User's Manual l MBa335x UM 0202 l © 2018, TQ-Systems GmbH
Page 19
4.2
Communication interfaces
4.2.1
USB 2.0 Hi-Speed Host
A USB hub provides five USB 2.0 Hi-Speed host interfaces. The hub provides an upstream port and seven downstream ports.
The USB connectors are supplied with 5 V by power distribution switches. The components used, provide current monitoring
and can switch off the bus voltage with overload and/or overheat. The USB2517 is clocked by an external 24 MHz oscillator.
USB host 1 and 2 are routed to a stacked USB Type-A connector (X7). USB host 3 is routed to a single Type-A connector (X8).
USB host 4 is available at header X4 on the MBa335x and USB host 6 at header X5 on the MBa335x. USB host 5 is available at
LVDS-CMD connector X18, USB host 7 is available at the Mini PCIe interface X22 (both on the bottom side of the MBa335x).
Illustration 12:
Block diagram USB-Hub
The USB host port of the TQMa335x provides a theoretical data rate of 480 Mbit/s. The data rate is shared amongst the
connected ports. The data rates of the ports can significantly deviate depending on the hardware and software used.
Table 23:
Characteristics USB
Parameter
Min.
Typ.
Max.
Unit
Voltage
4.75
5.00
5.25
V
Current
–
500
900
mA
Attention:
The "Uniflash tool" provided by TI cannot be used with the MBa335x, because USB0 is not directly
routed to a plug connector, but to a USB hub.
