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[nihq@red.semi.ac.cn]

Dear expert:

     I cannot understand How the usb_vbus_pad_i (Vcc of USB
connector) of UTMI interface effect the attached flag.

     I look look through the usbf_utmi_ls.v and find that if Vcc (
here is usb_vbus) is always logic "1", then the the machine state is 
always in powon or reset state.

always @(posedge clk or negedge rst)
	if(!rst)		state <= #1 POR;
	else
	if(usb_vbus)		state <= #1 POR;
	else			state <= #1 next_state;

    But you know the usb_vbus (Vcc) is always logic "1" when the
usb connector is powered. Then the usb_core will never work to 
the useful state. 
    Could any expert give me a hint?

    Thank Vikas T Rao for your previous answer!

best regards
NI haiqiao
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