
RM0008
Basic timers (TIM6&TIM7)
Doc ID 13902 Rev 12
457/1096
Figure 176. Counter timing diagram, update event when ARPE = 0 (TIMx_ARR not
preloaded)
Figure 177. Counter timing diagram, update event when ARPE=1 (TIMx_ARR
preloaded)
17.3.3 Clock
source
The counter clock is provided by the Internal clock (CK_INT) source.
The CEN (in the TIMx_CR1 register) and UG bits (in the TIMx_EGR register) are actual
control bits and can be changed only by software (except for UG that remains cleared
automatically). As soon as the CEN bit is written to 1, the prescaler is clocked by the internal
clock CK_INT.
shows the behavior of the control circuit and the upcounter in normal mode,
without prescaler.
00
CNT_EN
Timer clock = CK_CNT
Counter register
Update interrupt flag (UIF)
Counter overflow
Update event (UEV)
01 02 03 04 05 06 07
32 33 34 35 36
31
Auto-reload register
FF
36
Write a new value in TIMx_ARR
CK_INT
00
CNT_EN
Timer clock = CK_CNT
Counter register
Update interrupt flag (UIF)
Counter overflow
Update event (UEV)
01 02 03 04 05 06 07
F1 F2 F3 F4 F5
F0
Auto-reload preload register
F5
36
Auto-reload shadow register
F5
36
Write a new value in TIMx_ARR
CK_PSC