Figure 135. Triggering Timer 2 With Enable Of Timer 1 - STMicroelectronics STM32F05 series Reference Manual

RM0091

Figure 135. Triggering timer 2 with Enable of timer 1

TIMER1-CEN=CNT_EN
TIMER1-CNT_INIT
TIMER2-CNT_INIT
Using one timer as prescaler for another timer
For example, you can configure Timer 1 to act as a prescaler for Timer 2. Refer to
Figure 131
●
Configure Timer 1 master mode to send its Update Event (UEV) as trigger output
(MMS=010 in the TIM1_CR2 register). then it outputs a periodic signal on each counter
overflow.
● Configure the Timer 1 period (TIM1_ARR registers).
●
Configure Timer 2 to get the input trigger from Timer 1 (TS=000 in the TIM2_SMCR
register).
●
Configure Timer 2 in external clock mode 1 (SMS=111 in TIM2_SMCR register).
●
Start Timer 2 by writing '1 in the CEN bit (TIM2_CR1 register).
●
Start Timer 1 by writing '1 in the CEN bit (TIM1_CR1 register).
Starting 2 timers synchronously in response to an external trigger
In this example, we set the enable of timer 1 when its TI1 input rises, and the enable of
Timer 2 with the enable of Timer 1. Refer to
counters are aligned, Timer 1 must be configured in Master/Slave mode (slave with respect
to TI1, master with respect to Timer 2):
●
Configure Timer 1 master mode to send its Enable as trigger output (MMS=001 in the
TIM1_CR2 register).
● Configure Timer 1 slave mode to get the input trigger from TI1 (TS=100 in the
TIM1_SMCR register).
●
Configure Timer 1 in trigger mode (SMS=110 in the TIM1_SMCR register).
●
Configure the Timer 1 in Master/Slave mode by writing MSM=1 (TIM1_SMCR register).
●
Configure Timer 2 to get the input trigger from Timer 1 (TS=000 in the TIM2_SMCR
register).
●
Configure Timer 2 in trigger mode (SMS=110 in the TIM2_SMCR register).
CK_INT
TIMER1-CNT
75
TIMER2-CNT CD
TIMER2
write CNT
TIMER 2-TIF
for connections. To do this:
Doc ID 018940 Rev 1
General-purpose timers (TIM2 and TIM3)
00
00 E7
Write TIF=0
Figure 131 for connections. To ensure the
01 02
E8 E9 EA
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