User's Manual

UMTS/HSPA Module Series
UG95 Hardware Design
UG95_Hardware_Design Confidential / Released 22 / 67
let the module enter into the sleep mode.
 Execute AT command AT+QSCLK=1 to enable the sleep mode.
 Drive DTR to high level.
The following figure shows the connection between the module and application processor.
RXD
TXD
RI
DTR
AP_READY
TXD
RXD
EINT
GPIO
GPIO
Module
Processor
GND
GND
Figure 3: UART Sleep Application
The RI of module is used to wake up the processor, and AP_READY will detect the sleep state of
processor (can be configured to high level or low level detection). You should pay attention to the level
match shown in dotted line between module and processor. Drive DTR to low level will wake up the
module.
In sleep mode, the module can still receive paging message, SMS, voice call and TCP/UDP data from the
network normally, but the UART port is not accessible
3.5.1.2. USB Application with Suspend Function
TBD
3.5.1.3. USB Application without Suspend Function
If application processor communicates with module via USB interface, and processor does not support
USB suspend function, you should disconnect USB_VBUS with additional control circuit to let the module
enter into sleep mode.
 Execute AT command AT+QSCLK=1 to enable the sleep mode.
 Disconnect USB_VBUS.