User's Manual
Table Of Contents
- Contents
- Table Index
- Figure Index
- 0. Revision history
- 1. Introduction
- 2. Product concept
- 3. Application interface
- 3.1. Pin
- 3.2. Operating modes
- 3.3. Power supply
- 3.4. Power on and down scenarios
- 3.5. Charging interface
- 3.6. Power saving
- 3.7. Summary of state transitions
- 3.8. RTC backup
- 3.9. Serial interfaces
- 3.10. Audio interfaces
- 3.11. SIM card interface
- 3.12. SD card interface
- 3.13. PCM interface
- 3.14. ADC
- 3.15. Behaviors of the RI
- 3.16. Network status indication
- 3.17. Operating status indication
- 4. Antenna interface
- 5. Electrical, reliability and radio characteristics
- 6. Mechanical dimensions
- 7. Storage and manufacturing
- Appendix A: GPRS coding schemes
- Appendix B: GPRS multi-slot classes
M80 Hardware Design
M80_HD_V1.2 - 38 -
Emergency
shutdown pulse
EMERG_OFF
4.7K
47K
Figure 10: Reference circuit for EMERG_OFF by using driving circuit
S1
EMERG_OFF
TVS1
Close to S1
Figure 11: Reference circuit for EMERG_OFF by using button
3.4.3. Restart
3.4.3.1. Restart module using the PWRKEY pin
Customer’s application can restart the module by driving the PWRKEY to a low level voltage for
a certain time, which is similar to the way of turning on module. Before restarting the module, at
least 500ms should be delayed after detecting the low level of STATUS. The restart timing is
illustrated as the following figure.