LR1110
User Manual
Rev.1.0
UM.LR1110.W.APP
March 2020
19 of 130
Semtech
2.3.1 Power-On-Reset and Brown-Out Reset
If the battery voltage rises above the Power-On-Reset (POR) level, the LR1110 performs a restart. The LR1110 also features
a Brown-Out Reset (BRN), triggering a restart sequence if the battery voltage temporarily drops below the BRN level.
Both POR and BRN trigger a full restart of the internal firmware. The
Status
field of the
Stat2
status variable indicates if a POR
or BRN occurred.
5.4 Power-On-Reset and Brown-Out-Reset
for addition information on the POR and BRN.
2.3.2 NRESET
Putting the pin NRESET to low for at least 100 μs restarts the LR1110. The restart is equivalent to a Power-On Reset, and the
device will follow the same restart sequence.
2.3.3 Reboot Command
The command
Reboot( )
triggers a restart of the LR1110 firmware.
•
StayInBootLoader
= 0 performs a firmware restart.
•
StayInBootLoader
= 3: the boot-loader will not execute the FW in flash, but will allow FW upgrades.
•
Other values are RFU.
The configuration of the 32kHz clock will be kept on a Reboot. To modify the 32kHz clock configuration, the command
ConfigLFClock( )
shall be used.
2.4 Calibrations
During the startup sequence, the device firmware automatically launches the calibration of the low frequency and high
frequency RC oscillators, the PLL, the ADC, and the image rejection filter at 915MHz. At the end of the calibration procedure
the device is set in Standby RC mode.
In case of operation at another frequency, the image calibration procedure has to be restarted using the command
CalibImage( )
.
In case of change of the device temperature, the RC oscillators calibrations has to be re-executed using the command
Calibrate( )
.
Table 2-5: Reboot Command
Byte
0
1
2
Data from Host
0x01
0x18
StayInBootLoader
Data to Host
Stat1
Stat2
IrqStatus (31:24)
