topic Re: What is USB_OTG_VBUS pin? in i.MX Processors

What is USB_OTG_VBUS pin?

kriss — Tue, 06 Feb 2018 16:10:19 GMT

What is USB_OTGx_VBUS pin on imx7.

I'm asking cause there is no clear information neither in manual nor datasheet. What i can find, this pin is sensing input to power line of USB (?).

My device going to work as self-powered usb device. At the moment I follow sabre schematic diagram and i put mosfet switch between USB connector and USB_OTG1_VBUS pin. But I am thinking about simplify this to single resistor or straight wire to USB connector.

Regards

Krzyszof

Re: What is USB_OTG_VBUS pin?

igorpadykov — Tue, 06 Feb 2018 23:03:41 GMT

Hi Krzysztof

this signal is described in usb specifications found on usb.org and

used in nxp software bsps. In general it can be avoided, but software

modifications to usb driver should be implemented.

Best regards
igor
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Re: What is USB_OTG_VBUS pin?

kriss — Wed, 07 Feb 2018 09:39:46 GMT

Hi Igor,

Are you talking about usb2.0 spec? or any of spin-off standards?

So you are saying USB_OTG1_VBUS can be either source of 5V to connected device or can power whole imx7 in case i work as device?

p.s. I don't want to do any driver mods

Regards

Krzysztof

Re: What is USB_OTG_VBUS pin?

igorpadykov — Wed, 07 Feb 2018 23:51:44 GMT

Hi Krzysztof

it is used in usb driver described in Chapter 39 CHIPIDEA USB Driver

attached Linux Manual, one can look at sources listed in sect.39.2.2 Source Code Structure.

Best regards
igor