User's Manual

SARA-G3 and SARA-U2 series - System Integration Manual
UBX-13000995 - R18 Advance Information System description
Page 19 of 206
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:
x The internal 32 kHz oscillator (SARA-G340, SARA-G350 and SARA-U2 series)
x
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 modes 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 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 [3]).
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 to the u-blox AT Commands Manual [3], AT+UPSV).
The module wakes up from idle to active
mode in the following events:
x 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)
x 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)
x RTC alarm occurs (see u-blox AT Commands Manual [3], +CALA)
x Data received on UART interface, according to HW flow control
(AT&K) and power saving (AT+UPSV) settings (see 1.9.1.4)
x 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)
x DTR input line set to the ON state by the DTE, if AT+UPSV=3
power saving is set (see 1.9.1.4)
x USB detection, applying 5 V (typ.) to VUSB_DET input (see 1.9.3)
x The connected USB host forces a remote wakeup of the module
as USB device (see 1.9.3)
x 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
2
C) communication interface (see 1.11, 1.9.4)