LR1110
User Manual
Rev.1.0
UM.LR1110.W.APP
March 2020
15 of 130
Semtech
The command
SetStandby( )
sets the device in standby mode with the chosen 32MHz oscillator.
•
StdbyConfig = 0x00 selects the internal RC oscillator (Standby RC mode).
•
StdbyConfig = 0x01 selects the external Xtal/TCXO oscillator (Standby Xosc mode).
2.1.2 Power Down
This is the lowest power consumption mode of the device. In this mode, all clocks are stopped, and therefore no RTC is
available. Moreover, there is no data retention which means that a device reconfiguration is necessary when leaving the
power down mode. The BUSY signal is set to high in this mode, indicating to the host that the device is not ready to accept
a command.
The device is put in power down mode with the
SetSleep( )
command (refer to sleep mode description).
The device can exit this mode based on the detection of an event on a DIOs, or NSS pin. Exiting this mode, the device will
perform a firmware restart. When the BUSY pin is set to low, it indicates that the startup phase has been performed
successfully, and that the device is ready to accept a command.
2.1.3 Sleep
The Sleep mode allows configuring the LR1110 into a low power consumption mode between radio or geolocation
operations, while retaining the configuration register values and storing the firmware data in RAM.
An optional 32 kHz source is running either on the internal RC oscillator, or on the internal 32.768 kHz oscillator driving an
external crystal. The 32.768kHz crystal oscillator allows a faster transition to standby mode, at the expense of higher power
consumption. In both cases, the RTC uses the 32kHz clock source to allow an automatic wake-up from the Sleep mode.
The command
SetSleep( )
allows putting the device in Powerdown and Sleep mode, and configuring the timeout for
automatic wake-up.
Table 2-1: SetStandby Command
Byte
0
1
2
Data from Host
0x01
0x1C
StdbyConfig
Data to Host
Stat1
Stat2
IrqStatus(31:24)
Table 2-2: SetSleep Command
Byte
0
1
2
3
4
5
6
Data from Host
0x01
0x1B
SleepConfig
SleepTime
(31:24)
SleepTime
(23:16)
SleepTime
(15:8)
SleepTime
(7:0)
Data to Host
Stat1
Stat2
IrqStatus
(31:24)
IrqStatus
(23:16)
IrqStatus
(15:8)
IrqStatus
(7:0)
0x00
