DocID018909 Rev 11
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RM0090
General-purpose timers (TIM9 to TIM14)
687
Figure 194. Capture/compare channel 1 main circuit
Figure 195. Output stage of capture/compare channel (channel 1)
The capture/compare block is made of one preload register and one shadow register. Write
and read always access the preload register.
In capture mode, captures are actually done in the shadow register, which is copied into the
preload register.
In compare mode, the content of the preload register is copied into the shadow register
which is compared to the counter.
19.3.5 Input
capture
mode
In Input capture mode, the Capture/Compare Registers (TIMx_CCRx) are used to latch the
value of the counter after a transition detected by the corresponding ICx signal. When a
capture occurs, the corresponding CCXIF flag (TIMx_SR register) is set and an interrupt or
a DMA request can be sent if they are enabled. If a capture occurs while the CCxIF flag was
already high, then the over-capture flag CCxOF (TIMx_SR register) is set. CCxIF can be
CC1E
Capture/compare shadow register
comparator
Capture/compare preload register
Counter
IC1PS
CC1S[0]
CC1S[1]
capture
input
mode
S
R
read CCR1H
read CCR1L
read_in_progress
capture_transfer
CC1S[0]
CC1S[1]
S
R
write CCR1H
write CCR1L
write_in_progress
output
mode
UEV
OC1PE
(from time
compare_transfer
APB Bus
8
8
hig
h
lo
w
(if 16-b
it)
MCU-peripheral interface
TIM1_CCMR1
OC1PE
base unit)
CNT>CCR1
CNT=CCR1
TIM1_EGR
CC1G
/UTPUTMODE
#.4##2
#.4##2
CONTROLLER
4)-X?##-2
/#-;=
/#?2%&
##0
4)-X?##%2
/UTPUT
ENABLE
CIRCUIT
/#
##% 4)-X?##%2
4OTHEMASTERMODE
CONTROLLER
AI