Telit Wireless Solutions LM940 Design Guide

LM940 Hardware Design Guide
1VV0301352 Rev. 18 Page 37 of 75 2022-01-04
Not Subject to NDA
One of GPIO lines can be configured as Shutdown Indicators function by means of AT
commands: please refer to the AT User Guide for more details about AT#FASTSHDN and
AT#SHDNIND.
Figure 6: Fast Shutdown by AT Command
The DTE should monitor the status of Shutdown Indicator to proceed fast power-off.
Note: VBATT must not be removed before Shutdown Indicator goes
LOW.
Warning: Not following the recommended shut-down procedures
might damage the device and consequently void the warranty.
6.3.2.2. Fast Shutdown by GPIO
If properly configured, one of GPIO lines can be used as Fast Shutdown Trigger.
Once the Fast Shutdown Trigger senses a HIGH to LOW transition, fast shutdown is
initiated.
Then the LM940 module enters finalization state, terminates active processes, and
prepares to turn off safely. As shown in below figure, when the module is ready to be
turned off, it will be indicated via Shutdown Indicator.
Please refer to the AT User Guide for more detail about enable Shutdown Indicator and
Fast Shutdown Trigger.

Telit Wireless Solutions LM940 Specifications

General

Brand	Telit Wireless Solutions
Model	LM940
Category	Wireless modules
Language	English