Seco Qseven Q7-974 User Manual page 32

Rel. 2.0 comliant module with the intel bay trail family system-on-chips

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3.2.3.5

USB interface signals

Intel

Atom E38xx SOCs offer an xHCI controller, which is able to manage one Superspeed port (i.e. USB 3.0 compliant) and four USB 1.x / 2.0 Host ports, or,

alternatively, an EHCI Controller, which is able to manage only the four USB 1.x / USB 2.0 host ports. It is possible to select which one of the controllers (xHCI or

EHCI) must be enabled via BIOS settings (please check par. 4.3.3 for further details).

Furthermore, the SoC makes available one HSIC interface, which is used to manage an HSIC USB Hub that allows the module to have up to 6 USB 2.0 ports.

All USB 2.0 ports are able to work in High Speed (HS), Full Speed (FS) and Low Speed (LS).

Here following the signals related to USB interfaces.

USB_P0+/USB_P0-: Universal Serial Bus Port #0 differential pair (coming out from Intel

USB_P1+/USB_P1-: Universal Serial Bus Port #1 differential pair (coming out from Intel

USB_P2+/USB_P2-: Universal Serial Bus Port #2 differential pair (coming out from Intel

USB_P3+/USB_P3-: Universal Serial Bus Port #3 differential pair (coming out from Intel

USB_P4+/USB_P4-: Universal Serial Bus Port #4 differential pair (coming out from SMSC USB3503 HSIC USB Hub Downstream port #2).

USB_P5+/USB_P5-: Universal Serial Bus Port #5 differential pair (coming out from SMSC USB3503 HSIC USB Hub Downstream port #3).

USB_SSRX0+/USB_SSRX0-: USB Super Speed Port #0 receive differential pair; it is managed by xHCI controller.

USB_SSTX0+/USB_SSTX0-: USB Super Speed Port #0 transmit differential pair; it is managed by xHCI controller.

USB_0_1_OC#: USB Over Current Detect Input. Active Low Input signal, electrical level +3.3V_A with 10kΩ pull-up resistor. This pin has to be used for

overcurrent detection of USB Port#0 and #1 of Q7-974 module

USB_2_3_OC#: USB Over Current Detect Input. Active Low Input signal, electrical level +3.3V_A with 10kΩ pull-up resistor. This pin has to be used for

overcurrent detection of USB Ports #2 and #3 of Q7-974 module

USB_4_5_OC#: USB Over Current Detect Input. Active Low Input signal, electrical level +3.3V_A with 10kΩ pull-up resistor. This pin has to be used for

overcurrent detection of USB Port #4 and/or #5 of Q7-974 module (those managed by SMSC USB 3503 HSIC USB Hub)

Please notice that for correct management of Overcurrent signals, power distribution switches are needed on the carrier board.

For EMI/ESD protection, common mode chokes on USB data lines, and clamping diodes on USB data and voltage lines, are also needed.

The schematics in the following page show an example of implementation on the Carrier Board. In there, USB ports #1, #2, #3, #4 and #5 are carried out to

standard USB 2.0 Type A receptacles, while USB 2.0 port #0, along with the Superspeed USB port, is carried to a standard USB 3.0 Type A receptacle. For

correct implementation of USB 3.0 connection, the Superspeed port must be paired with USB 2.0 port #0.

Q7-974

Atom E38xx SoC).

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