imx27 - USB Over Current

[imx_user]

Has anyone tested the USB over current function of iMX27?

I configure "USB_OC_B" to act as USB Host 1 over current detection pin, but when I trigger this pin, both Host 1 and Host 2 over current interrupts come in.

The USB Configuration Register settings is:

USB_CTRL(600h)=0x59494030.

When I simulated over current on "USB_OC_B" pin, the following debug messages comes in:

GetPortStatus host 2 = 0x80001831, USBSTS=0xC48C, SysIntr=23

GetPortStatus host 1 = 0xE0501831, USBSTS=0xC08C, SysIntr=24

Anyone can advise me? Thanks in advance.

[art · Accepted solution]

The USB_OC_B signal operates as the common overcurrent signal for both USB Host and OTG (in Host mode) cores of i.MX27, so, the behaviour you observe is the normal one. If you want to dedicate this signal for a single core (e.g. USB Host core only), just disable the overcurrent interrupt for another one.

Have a great day,
Artur

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