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GSM/GPRS Module Series
M66 Hardware Design
M66_Hardware_Design Confidential / Released 30 / 80
3.5.3. Wake Up Module From SLEEP Mode
When the module is in the SLEEP mode, the following methods can wake up the module.
If the DTR Pin is set low, it would wake up the module from the SLEEP mode. The UART port will be
active within 20ms after DTR is changed to low level.
Receive a voice or data call from network wakes up module.
Receive an SMS from network wakes up module.
DTR pin should be held at low level during communication between the module and DTE.
3.5.4. Summary of State Transition
Table 6: Summary of State Transition
3.6. RTC Backup
The RTC (Real Time Clock) function is supported. The RTC is designed to work with an internal power
supply.
There are three kinds of designs for RTC backup power:
Use VBAT as the RTC power source.
When the module is turned off and the main power supply (VBAT) is remained, the real time clock is still
active as the RTC core is supplied by VBAT. In this case, the VRTC pin can be kept floating.
Current Mode
Next Mode
Power Down
Normal Mode
Sleep Mode
Power Down
Use PWRKEY
Normal Mode
AT+QPOWD
, use
PWRKEY pin
Use AT command
AT+QSCLK=1
and pull up
DTR
SLEEP Mode
Use PWRKEY pin
Pull DTR down or incoming
call or SMS or GPRS
NOTE
Quectel
Confidential