LR1110
User Manual
Rev.1.0
UM.LR1110.W.APP
March 2020
16 of 130
Semtech
•
The
SleepConfig
bits define in which sleep mode the device is put, and if it wakes up after a given time on the RTC
event:
Retention
bit (bit 0) defines if the device configuration and the firmware data are retained.
Retention
=1: 8 kB of memory used for device state and firmware data retention.
Retention
=0: no data retention.
Wakeup
bit (bit 1) determines if the device wakes up after a given time on the RTC event.
Wakeup
=1: automatic wake-up enabled. The device will automatically go in Standby mode with RC oscillator, at
the end of the
SleepTime
timer. The 32 kHz clock source is configured using the command
ConfigLFclock ( )
for
modem applications.
Wakeup
=0: automatic wake-up disabled.
Other bits are RFU and should be set to 0.
•
SleepTime
: sleep time in number of 32.768 kHz clock cycles, prior to automatic wake-up. Therefore, the sleep time can
vary from 0 ms to 36.4 hours in steps of 30.52us.
BUSY is set to 1 in sleep mode.
The device can exit this mode based on the detection a falling edge on the 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.
The following table summarizes the different sleep modes according to the Retention and Wakeup bits configuration, with
their current consumption and Standby transitions times (indicative values, for comparison only).
The mode
Retention
=1 and
Wakeup
=0 is a valid usage mode, but does not correspond to any datasheet description.
Table 2-3: SleepConfig Parameter
SleepConfig bit
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Definition
RFU
RFU
RFU
RFU
RFU
RFU
Wakeup
Retention
Table 2-4: Sleep Mode Summary
Retention
Wakeup
Datasheet
Indicative Consumption (uA)
RC /XTAL
Indicative Transition to Stby
(ms)
0
0
Powerdown
IDDPDN
30
0
1
Sleep
IDDSL1 / IDDSL2
30
1
0
-
-
-
1
1
Sleep w/ 8kB retention
IDDSL3A / IDDSL4A
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