User's Manual
Table Of Contents
- Contents
- Figures
- Tables
- Document history
- Introduction
- Product concept
- GSM application interface
- GSM/GPRS operating modes
- Power supply
- Power up / down scenarios
- Automatic GPRS Multislot Class change
- Charging control of the GSM part
- Power saving
- Summary of state transitions (except SLEEP mode)
- RTC backup for GSM part of XT55/56
- Serial interfaces of the XT55/56 GSM part
- Audio interfaces
- SIM interface
- Control signals
- GPS application interface
- GSM and GPS antenna interfaces
- Electrical, reliability and radio characteristics
- Mechanics
- Reference approval
- Example applications
- List of parts and accessories
XT55/56 Hardware Interface Description
Confidential / Released
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XT55/56_hd_v02.06a Page 30 of 125 17.12.2004
3.3 Power up / down scenarios
In general, be sure not to turn on GSM part of the XT55/56 module while it is out of the
operating range of voltage and temperature stated in Chapters 6.2 and 6.3. The GSM part of
the XT55/56 would immediately switch off after having started and detected these
inappropriate conditions.
3.3.1 Turn on the GSM part of XT55/56
The GSM part of the XT55/56 can be activated in a variety of ways, which are described in
the following chapters:
• via ignition line GSM_IGT: starts normal operating state (see Chapters 3.3.1.1 and
3.3.1.2)
• via GSM_POWER line: starts charging algorithm (see Chapters 3.5.4 and 3.3.1.3)
• via RTC interrupt: starts Alarm mode (see Chapter 3.3.1.4)