ST STM32G471 User Manual

RM0440 Rev 4 1115/2126
RM0440 Advanced-control timers (TIM1/TIM8/TIM20)
1226
The period and the pulsewidth of a PWM signal applied on tim_ti1 can be measured using
the following procedure:
• Select the active input for TIMx_CCR1: write the CC1S bits to 01 in the TIMx_CCMR1
register (tim_ti1 selected).
• Select the active polarity for tim_ti1fp1 (used both for capture in TIMx_CCR1 and
counter clear): write the CC1P and CC1NP bits to ‘0’ (active on rising edge).
• Select the active input for TIMx_CCR2: write the CC2S bits to 10 in the TIMx_CCMR1
register (tim_ti1 selected).
• Select the active polarity for tim_ti1fp2 (used for capture in TIMx_CCR2): write the
CC2P and CC2NP bits to CC2P/CC2NP=’10’ (active on falling edge).
• Select the valid trigger input: write the TS bits to 00101 in the TIMx_SMCR register
(tim_ti1fp1 selected).
• Configure the slave mode controller in reset mode: write the SMS bits to 0100 in the
TIMx_SMCR register.
• Enable the captures: write the CC1E and CC2E bits to ‘1’ in the TIMx_CCER register.
Figure 300. PWM input mode timing
28.3.11 Forced output mode
In output mode (CCxS bits = 00 in the TIMx_CCMRx register), each output compare signal
(tim_ocxref and then tim_ocx/tim_ocxn) can be forced to active or inactive level directly by
software, independently of any comparison between the output compare register and the
counter.
To force an output compare signal (tim_ocxref/tim_ocx) to its active level, user just needs to
write 0101 in the OCxM bits in the corresponding TIMx_CCMRx register. Thus tim_ocxref is
forced high (tim_ocxref is always active high) and tim_ocx get opposite value to CCxP
polarity bit.
For example: CCxP=0 (tim_ocx active high) => tim_ocx is forced to high level.
The tim_ocxref signal can be forced low by writing the OCxM bits to 0100 in the
TIMx_CCMRx register.
MSv62325V1
tim_ti1
TIMx_CNT
TIMx_CCR1
TIMx_CCR2
IC1 capture
IC2 capture
reset counter
IC2 capture
pulse width
measurement
IC1 capture
pulse width
measurement
0004 0000 0001 0002 0003 0004 0000
0004
0002

ST STM32G471 Specifications

General

Brand	ST
Model	STM32G471
Category	Microcontrollers
Language	English