LTE Standard Module Series
EG915U_Series_Hardware_Design 27 / 81
3.2.2. USB Application Scenario
If the host supports USB suspend/resume and remote wakeup functions, the following three preconditions
can make the module enter the sleep mode.
⚫
Execute
AT+QSCLK=1
to enable the sleep mode.
⚫
Ensure the MAIN_DTR is kept at high level or kept open.
⚫
Ensure t
he host’s USB Bus, which is connected with the module’s USB interface, enters suspend
state.
The following figure shows the connection between the module and the host.
3.2.2.1. USB Application with USB Remote Wakeup Function
The host supports USB Suspend/Resume and remote wakeup function.
The following figure illustrates 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 Mode Application with USB Remote Wakeup
⚫
You can wake up the module by sending data to it through USB.
⚫
When the module has a URC to report, the module will send remote wakeup signals via USB bus so
as to wake up the host.
⚫
NOTE