iMX6 USB OC functionality

[martinchristian]

Hi,

I have been looking for information about the OC (Over Current) and USB Power Enable functionality in the iMX6.

I have a USB Host interface, with a external USB power switch with an "over current" output which is active low and a Enable input which is active low.

The Freescale evaluation board, (Smart Device Platform) have a similar device, but with OC output active low and USB Power EN active high.

So, can I change the USB_H1_PWR_EN signal to support the active low input of my USB power switch?

Can someone explain how thiese signals (USB_H1_PWR_EN, USB_H1_OC) function in the device.

(I have looked through Freescale documentation...)

PS. I would like to keep the USB power switch that I currently use. I know it is possible to get a version with active high EN input.

Best Regards,

Martin C.

[igorpadykov]

Hi Martin,

USB_PWR_EN is the output signal, meant to switch

on/off a VBUS power source for the USB bus, affected by

PP bit in PORTSC register . USB_OC is VBUS Over Current input signal,

when it is asserted - Over Current related bits will be set / active. 

imx6 hdimidogle usb_otg_oc

>can I change the USB_H1_PWR_EN signal to support the active low input of my USB power switch?

No. USB_H1_OC "over current" polarity also can not be changed.

However you can use gpios (one will have to change usb driver) for these signals

and use any desirable polarity you wishes.

Best regards

chip

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