LS1028 power sequencing for USB_VBUS

[sereza1981]

Hello!

Dear, could you please let me know LS1028 SoC power sequencing for USBx_VBUS domain?

I couldn't find such information in datasheets.

Thank you!

Sergej.

[sereza1981]

I tell another words: do you have any power sequencing restriction of USB_VBUS domain referenced to another power domains of LS1028?

Thank you!

Sergej.

[ufedor · Accepted solution]

USB_VBUS has to be applied at any moment after completion of the processor power sequence.

[sereza1981]

I need information about USB_VBUS power sequencing referenced to another LS1028 power domains.

If I have USB hub connected to LS1028 USB port, that USB hub has external USB Type-A port and another permanent connected devices to  the USB hub another ports. So when I need to switch on/off power on USB_VBUS of LS1028?

Thank you!

Sergej.

[ufedor]

When operating as device, VBUS will be supplied by the host (devices never provide VBUS). In this case Vbus will be on when the USB cable is connected and the host has turned-on Vbus (normally always on).

When operating as Host, it is the responsibility of the USB driver to turn-on VBUS.