Hi NXP,
We refer NXP SDK_2_14_0_FRDM-MCXN236_rfp USB device example to develop a USB device. However, is it possible to make the USB device mode work without VBUS?
If yes, how can we modify this in the SDK?
Thanks,
Alan
Solved! Go to Solution.
Hi @allu
Thank you very much for your patience.
As I reviewed internally, please find below our feedback.
We strongly suggest customers to link MCX N2xx's USB_VBUS pin with USB connector as recommended in our hardware design guide and implemented in the official FRDM-MCX N 236 schematic.
With the USB_VBUS pin detect, the application firmware can easily know if the USB is attached or not.
Leaving USB_VBUS floating is possible, but require the software skip the attach detection, and use a software state machine to check if the USB is linked or not. But we are not sure about the workload to implement this.
Additonally, leaving USB_VBUS disconnect may impact on the USB certification attach and de-attach test, but it will not impact on other test items. As mentioned before, you may use the software approach to solve the attach and de-attach test item issue, but it is not our recommendation.
Anyway, we strongly suggest you to enable the USB_VBUS.
Thank you,
Diego
Hi @allu
Thank you very much for your patience.
As I reviewed internally, please find below our feedback.
We strongly suggest customers to link MCX N2xx's USB_VBUS pin with USB connector as recommended in our hardware design guide and implemented in the official FRDM-MCX N 236 schematic.
With the USB_VBUS pin detect, the application firmware can easily know if the USB is attached or not.
Leaving USB_VBUS floating is possible, but require the software skip the attach detection, and use a software state machine to check if the USB is linked or not. But we are not sure about the workload to implement this.
Additonally, leaving USB_VBUS disconnect may impact on the USB certification attach and de-attach test, but it will not impact on other test items. As mentioned before, you may use the software approach to solve the attach and de-attach test item issue, but it is not our recommendation.
Anyway, we strongly suggest you to enable the USB_VBUS.
Thank you,
Diego