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Full USB Host on i.MX 6SX

Question asked by DBMicro on Apr 29, 2015
Latest reply on May 3, 2015 by igorpadykov

We are trying to provide a full USB Host connection with an i.MX 6 SoloX. My circuit for the USB interface is the following:

 

  • NVCC_USB_H is not powered because the HSIC interface is not used
  • USB_OTG2_VBUS and USB_OTG1_VBUS have their decoupling capacitors
  • VDD_USB_CAP has its capacitors connected
  • USB_OTG2_VBUS is not powered
  • USB_OTG1_VBUS is powered by 5V
  • USB_OTG1_DN and USB_OTG1_DP are connected to the USB connector (via Choke and protection)
  • USB_OTG1_ID is tied to ground
  • USB_OTG1_OC is connected to the overcurrent detection of the power Switch
  • USB-OTG1_PWR is connected to the enable-input of the Power switch
  • The power switch is shorted (5V will always be available on the connector, for testing purposes)
  • USB_OTG1_CH_B is floating
  • OTG2 Port is not in use

 

The Sabre Board provides two USB connections: one USB on the go and one USB Host (as noted on the Board's silksreen). As i reviewed the Sabre Board schematic the only differences to the "Host" USb connection are:

  • We use OTG1 data ports instead of OTG2
  • NVCC_USB_H is not powered in our solution

 

The Linux we are running does not even Probe the USB connection when connecting a USB Device (not a host). The Device seems to be powered correctly. So the question now is:

  1. Is it possible to get a full USB Host without using the HSIC interface (as noted on the Sabre Board)?
  2. Is the OTG1 Port capable of providing a USB Host connection or is this only possible via OTG2?
  3. Does NVCC_USB_H has to be powered to use the OTG ports?

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