SARA-G3 and SARA-U2 series - System Integration Manual
UBX-13000995 - R26
System description
Page 22 of 217
1.4
Operating modes
SARA-G3 modules have several operating modes. The operating modes defined in Table 4 and described in
detail in Table 5 provide general guidelines for operation.
General Status
Operating Mode
Definition
Power-down
Not-powered mode
VCC
supply not present or below operating range: module is switched off.
Power-off mode
VCC
supply within operating range and module is switched off.
Normal operation
Idle mode
Module processor core runs with 32 kHz reference, that is generated by:
The internal 32 kHz oscillator (SARA-G340, SARA-G350 and SARA-U2 series)
The 32 kHz signal provided at the
EXT32K
pin (SARA-G300 and SARA-G310)
Active mode
Module processor core runs with 26 MHz reference generated by the internal oscillator.
Connected mode
Voice or data call enabled and processor core runs with 26 MHz reference.
Table 4: Module operating mode definition
Operating
Mode
Description
Transition between operating modes
Not-Powered
Module is switched off.
Application interfaces are not accessible.
Internal RTC operates on SARA-G340/G350,
SARA-U2 if a valid voltage is applied to
V_BCKP
.
Additionally, a proper external 32 kHz signal
must be fed to
EXT32K
on SARA-G300/G310
modules to let internal RTC timer running.
When
VCC
supply is removed, the module enters not-powered mode.
When in not-powered mode, the modules cannot be switched on by
PWR_ON
,
RESET_N
or RTC alarm.
When in not-powered mode, the modules can be switched on applying
VCC
supply (see 2.3.1) so that the module switches from not-powered
to active mode.
Power-Off
Module is switched off: normal shutdown by an
appropriate power-off event (see 1.6.2).
Application interfaces are not accessible.
Internal RTC operates on SARA-G340/G350,
SARA-U2 as
V_BCKP
is internally generated.
A proper external 32 kHz signal must be fed to
the
EXT32K
pin on SARA-G300/G310 to let RTC
timer running that otherwise is not in operation.
When the module is switched off by an appropriate power-off event
(see 1.6.2), the module enters power-off mode from active mode.
When in power-off mode, the modules can be switched on by
PWR_ON
,
RESET_N
or RTC alarm (see 2.3.1): the module switches
from power-off to active mode.
When
VCC
supply is removed, the module switches from power-off
mode to not-powered mode.
Idle
The module is not ready to communicate with
an external device by means of the application
interfaces as configured to reduce consumption.
The module automatically enters idle mode
whenever possible if power saving is enabled by
the AT+UPSV command (see the
u-blox AT
Commands Manual
[3]), reducing power
consumption (see section 1.5.1.4).
The
CTS
output line indicates when the UART
interface is disabled/enabled due to the module
idle/active mode according to power saving and
HW flow control settings (see 1.9.1.3, 1.9.1.4).
Power saving configuration is not enabled by
default: it can be enabled by AT+UPSV (see the
u-blox AT Commands Manual
A proper 32 kHz signal must be fed to the
EXT32K
pin of SARA-G300/G310 modules to let
idle mode that otherwise cannot be reached
(this is not needed for the other SARA-G3 and
SARA-U2 series modules).
The module automatically switches from active mode to idle mode
whenever possible if power saving is enabled (see sections 1.5.1.4,
1.9.1.4 and the
u-blox AT Commands Manual
[3], AT+UPSV).
The module wakes up from idle to active mode in the following events:
Automatic periodic monitoring of the paging channel for the
paging block reception according to network conditions (see
1.5.1.4, 1.9.1.4)
Automatic periodic enable of the UART interface to receive and
send data, if AT+UPSV=1 power saving is set (see 1.9.1.4)
RTC alarm occurs (see the
u-blox AT Commands Manual
+CALA)
Data received on the UART interface, according to HW flow
control (AT&K) and power saving (AT+UPSV) settings (see 1.9.1.4)
RTS
input line set to the ON state by the DTE, if HW flow control
is disabled by AT&K0 and AT+UPSV=2 is set (see 1.9.1.4)
DTR
input line set to the ON state by the DTE, if AT+UPSV=3
power saving is set (see 1.9.1.4)
USB detection, applying 5 V (typ.) to
VUSB_DET
input (see 1.9.3)
The connected USB host forces a remote wakeup of the module
as a USB device (see 1.9.3)
GNSS data ready: when the
GPIO3
pin is informed by the
connected u-blox GNSS receiver that it is ready to send data over
the DDC (I
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