
AirPrime XS1110 AT Command Reference
Rev 3.1 Jul.20
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Table 2
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3: Sleep States
Sleep
State
Main RAM
status
a
a. The main RAM contains the firmware (GNSS kernel firmware and GNSS systems) and all data
during GNSS reception.
Backup RAM
status
b
b. The backup RAM stores the ephemeris, almanac, position, and TCXO offset information
needed for a hot start.
Module activity upon waking up
Sleep 0
c
c. When the module enters a Sleep 0 state, the backup RAM and the main RAM are still powered.
Thus, when the module wakes up, it continues to execute the previous program. Since data for
the backup RAM is retained, the module can execute a hot start. When the module wakes up, it
responds with +GNSSLP,WAKEUP,OK. There are three ways to wake up the module from a
Sleep 0 state: module timeout, using the wakeup pin, interrupting via interface. Sending any
data on the UART/I2C can wake up the module from a Sleep 0 state. It is recommended to
send a dummy data before sending an actual command to prevent losing transmission data
when the module wakes up.
Sleep 0 State
Retained
Retained
Re-start with previous setting (hot start).
Sleep 1
d
Off
Retained
Reboot