User's Manual

0
LTE Module
EC25-A User Manual
EC25-A_User_Manual Confidential / Released 23 / 7
Refer to AT command AT+QCFG=“apready” for details.
3.5.1.2. USB Application with USB Remote Wakeup Function
If host supports USB suspend/resume and remote wakeup function, the following part will show the sleep
application.
There are three preconditions to let the module enter into the sleep mode.
 Execute AT command AT+QSCLK=1 to enable the sleep mode.
 Ensure the DTR is held in high level or keep it open.
 The host’s USB bus, which is connected with the module’s USB interface, enters into suspended
state.
The following figure shows the connection between the module and the host.
USB_VBUS
USB_DP
USB_DM
AP_READY
VDD
USB_DP
USB_DM
GPIO
Module
Host
GND
GND
Figure 4: Sleep Application with USB Remote Wakeup
 Sending data to EC25 through USB will wake up the module.
 When EC25 has URC to report, the module will send remote wake-up signals to USB BUS so as to
wake up the host.
3.5.1.3. USB Application with USB Suspend/Resume and RI Function
If host supports USB suspend/resume, but does not support remote wake-up function, the RI signal is
needed to wake up the host. The following part will show the sleep application.
There are three preconditions to let the module enter into the sleep mode.
 Execute AT command AT+QSCLK=1 to enable the sleep mode.
 Ensure the DTR is held in high level or keep it open.
 The host’s USB bus, which is connected with the module’s USB interface, enters into suspended