I'm moving an application that runs on a K20 processor (Teensy 3.2) to a Cortex M7 (Teensy 4.0). On the K20 I was able to use the LINESTATESTABLE field in the OTGSTAT register to reliably tell via software if the device was connected to a windows PC. How can I tell if the usb cable is connected to a windows pc or not. So far I've tried the following, none of which changed state when the USB cable was unplugged:
USBPHY_STATUS OTGID_STATUS (bit 8) and DEVPLUGIN_STATUS (bit 6)
USB1_OTGSC bits 8-10 related to Vbus,
USB1_USBSTS PCI bit 2 port change detect
What field can I test to see if there is a USB connection or not? At over 3500 pages, the i.MX RT1060 Processor Reference Manual probably holds the answer, I can't seem to find it. Any help would be greatly appreciated