User Manual

GSM/GPRS Module Series
GC10 Hardware Design
GC10_Hardware_Design Confidential / Released 32 / 76
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 to low level, it would wake up the module from the sleep mode.
 Receive a voice or GPRS data from network to wake up module.
 Receive an SMS from network to wake up module.
DTR pin should be kept in low level during communication between the module and DTE.
3.5.4. Summary of State Transition
Table 5: Summary of State Transition
3.6. RTC Backup
The RTC (Real Time Clock) can be supplied by an external capacitor or battery (rechargeable or
non-chargeable) through the pin VRTC. A 2.2K resistor has been integrated in the module for current
limiting. A coin-cell battery or a super-cap can be used to backup power supply for RTC.
The following figures show various sample circuits for RTC backup.
Current Mode
Next Mode
Power Down Normal Mode Sleep Mode
Power Down Use PWRKEY
Normal Mode
AT+QPOWD, use PWRKEY
pin, or use EMERG_OFF pin
Use AT command
“AT+QSCLK=1” and pull up
DTR
Sleep Mode
Use PWRKEY pin, or use
EMERG_OFF pin
Pull down DTR or
incoming voice call or
SMS or GPRS data
NOTE