In IMXRT1050 reference manual it said:
56.2.5.4 Switchable 1.5KΩ USB_DP Pullup Resistor
This product contains a switchable 1.5 KΩ pullup resistor on the USB_n_DP signal.
This resistor is switched on to indicate to the host/hub controller that a full-speed-capable device is on the USB cable, powered on, and ready. This resistor is switched off at power-on reset so the host does not recognize a USB device until the processor software enables the announcement of a full-speed device.
but hasn’t mentioned how to enable this internal pull-up resistor, and I cannot find any external pull-up resister on the board, so my PC cannot detect if device plugged in. What should I do now?
Hi David
usb module controls this bit automatically internally during usb connection
procedure, seems there is no way to manually in software control it.
Best regards
igor
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And my device does undetectable in this moment. I think USB port is just a analog detectable circuit, when the pull-up on DP or DN was detected, HOST should send the description request automatically without any other condition, even USB control not be started right? I tried use Wireshark to monitor the USB request, but nothing was captured.
what is about other devices, USB module perform enumeration process using on own state machine,
you can try examples with i.MXRT1050 EVK and its MCUXpresso software
Welcome | MCUXpresso SDK Builder
Best regards
igor