Usb Ports - Seco SBC-C20 User Manual

USB ports

The i.MX8M processor offers totally 2 USB interfaces, which can be expanded by using an optional SMSC USB2514 USB 2.0 Hi-Speed Hub Controller.
USB 3.0 port Type-A connector - CN17
Pin Signal
1 +5V
USB1
2 USB_H1-
3 USB_H1+
4 GND
USB_SSRX1-
5
USB_SSRX1+
6
GND
7
8 USB_SSTX1-
9 USB_SSTX1+
USB recovery connector CN23
Pin Signal
1 USB_VBUS_RECOVERY
2 USB_D1-
3 USB_D1+
4 ---
5 GND
Signal description of this port:
USB_D1+/USB_D1-: USB Device Port #1 differential pair.
USB_VBUS_RECOVERY: Recovery USB voltage rail input.
SBC-C20
SBC-C20 User Manual - Rev. First Edition: 1.0 - Last Edition: 1.0 - Author: A.R. - Reviewed by C.M. -Copyright © 2020 SECO S.p.A.
The first USB port is connected directly a standard USB 3.0 type-A connector, described in the
table on the left. This interface is mutually exclusive with
Signal description of this port:
USB_H1+/USB_H1-: USB 2.0 Host Port #1 differential pair;
USB_SSRX1+/USB_SSRX1-: USB Super Speed Port #1 receive differential pair;
USB_SSTX1+/USB_SSTX1-: USB Super Speed Port #1 transmit differential pair;
Common mode chokes are placed on all USB differential pairs for EMI compliance. For ESD protection, on all
data and voltage lines are placed clamping diodes for voltage transient suppression.
The USB 2.0 port available on USB 3.0 connector can be switched to a standard micro-AB
connector, described in the table on the left. This connector must be used only for recovery
purposes.
Working of this port is fixed in client mode.
When a microB plug is connected to CN23, then the external voltage provided on pin#1 will force automatically the
switching of the USB 2.0 port to connector CN23.
In any case, the switching of the USB port is controlled via a 2-way jumper, JP1, which can be used to
force i.MX8M processor in recovery mode. For normal working of the board, this jumper must not be
inserted.
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