2 Replies Latest reply on Apr 8, 2019 7:59 PM by JeHu_3414236

    USB cannot enumerate after switching to bootloader

    JeHu_3414236

      I have USB CDC enabled in my PSoC 62 application and bootloader.  When I switch from the application to the bootloader using the function Cy_Bootload_ExecuteApp(0), USB will not enumerate after the bootloader starts.  The device manager shows Unknown USB Device (Device Descriptor Request Failed).  Before calling Cy_Bootload_ExecuteApp(0) I call USBFS_Stop() and delayed 10s before starting bootloader and I still see this problem.  The USB device disappears from the PC device manager 2s after I call USBFS_Stop().  When the bootloader starts running, I see the Unknown USB Device error even before I initialized USB so I think USBFS_Stop() is not enough to reset the USB state on the PSoC.  What else do I need to do in the application or bootloader to allow USB to work across app switch to bootloader?