The RI behavior can be changed by AT+QCFG="urc/ri/ring" command. Please refer to document [2] for
details.
3.20. USB_BOOT Interface
EG25-G provides a USB_BOOT pin. Customers can pull up USB_BOOT to VDD_EXT before powering
on the module, thus the module will enter into emergency download mode when powered on. In this mode,
the module supports firmware upgrade over USB interface.
Table 24: Pin Definition of USB_BOOT Interface