RM0008 General-purpose timers (TIM2 to TIM5)
Doc ID 13902 Rev 12 363/1096
15.3.4 Capture/compare channels
Each Capture/Compare channel is built around a capture/compare register (including a
shadow register), a input stage for capture (with digital filter, multiplexing and prescaler) and
an output stage (with comparator and output control).
The following figure gives an overview of one Capture/Compare channel.
The input stage samples the corresponding TIx input to generate a filtered signal TIxF.
Then, an edge detector with polarity selection generates a signal (TIxFPx) which can be
used as trigger input by the slave mode controller or as the capture command. It is
prescaled before the capture register (ICxPS).
Figure 125. Capture/compare channel (example: channel 1 input stage)
The output stage generates an intermediate waveform which is then used for reference:
OCxRef (active high). The polarity acts at the end of the chain.
Figure 126. Capture/compare channel 1 main circuit
TI1
0
1
TIMx_CCER
CC1P
divider
/1, /2, /4, /8
ICPS[1:0]
TI1F_ED
filter
ICF[3:0]
downcounter
TIMx_CCMR1
Edge
Detector
TI1F_Rising
TI1F_Falling
to the slave mode controller
TI1FP1
11
01
TIMx_CCMR1
CC1S[1:0]
IC1
TI2FP1
TRC
(from channel 2)
(from slave mode
controller)
10
f
DTS
TIMx_CCER
CC1E
IC1PS
TI1F
0
1
TI2F_rising
TI2F_falling
(from channel 2)
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
high
low
(if 16-bit)
MCU-peripheral interface
TIMx_CCMR1
OC1PE
base unit)
CNT>CCR1
CNT=CCR1
TIMx_EGR
CC1G
To Next Page
Loading...
Need help?
General
