Table of Contents
Advertisement
21.3.6.1 Triggered Output Generation
If both LETIMERn_CNT and LETIMERn_REP0 are 0 in buffered mode, and COMP0TOP and BUFTOP in LETIMERn_CTRL are set,
the values of LETIMERn_COMP1 and LETIMERn_REP1 are loaded into LETIMERn_CNT and LETIMERn_REP0 respectively when
the timer is started. If no additional writes to LETIMERn_REP1 are done before the timer stops, LETIMERn_REP1 determines the num-
ber of pulses/toggles generated on the output, and LETIMERn_COMP1 determines the period lengths.
As the RTC can be used via PRS to start the LETIMER, the RTC and LETIMER can thus be combined to generate specific pulse-trains
at given intervals. Software can update LETIMERn_COMP1 and LETIMERn_REP1 to change the number of pulses and pulse-period in
each train, but if changes are not required, software does not have to update the registers between each pulse train.
For the example in
Figure 21.11 LETIMER Triggered Operation on page
pulses with 3 cycle periods, or a single pulse 3 cycles wide every time the LETIMER is started. After the output has been generated, the
LETIMER stops, and is ready to be triggered again.
Initial configuration,
REP1 just written
TOP1
TOP0
CNT
REP0
REP1
Int. flags set
LFACLK
LETIMERn
LETn_O0
UFOA0 = 01
LETn_O1
UFOA0 = 10
silabs.com | Building a more connected world.
Stop
2
2
2
2
2
2
2
2
2
X
2
2
2
2
2
2
2
2
0
2
1
0
2
1
0
0
0
0
2
2
2
1
1
1
0
0
2
2
2
2
2
2
2
2
2
u
u
u
u
u
u
u
UFIF
UFIF
REP0IF
Figure 21.11. LETIMER Triggered Operation
725, the initial values cause the LETIMER to generate two
Write
START=1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
0
0
0
2
1
0
2
1
0
0
0
2
2
2
1
1
2
2
2
2
2
2
2
2
u
u
u
u
u
u
u
u
u
UFIF
REP0IF
Reference Manual
LETIMER - Low Energy Timer
Write
START=1
Stop
2
2
2
2
2
2
2
2
2
2
2
2
2
2
0
0
0
0
2
1
0
0
1
0
0
2
2
2
2
2
2
2
2
2
2
u
u
u
u
u
u
u
UFIF
UFIF
Rev. 1.1 | 725
Advertisement
Table of Contents
Need help?
Do you have a question about the EFR32xG14 Wireless Gecko and is the answer not in the manual?