ST STM32L4+ Series Reference Manual page 1312

General-purpose timers (TIM2/TIM3/TIM4/TIM5) RM0432
Figure 355. Counter timing diagram, internal clock divided by 4
CK_PSC
CNT_EN
Timerclock = CK_CNT
Counter register
0001
0000 0000 0001
Counter underflow
Update event (UEV)
Update interrupt flag
(UIF)
MS31186V1
Figure 356. Counter timing diagram, internal clock divided by N
CK_PSC
Timerclock = CK_CNT
20 1F 00 36
Counter register
Counter underflow
Update event (UEV)
Update interrupt flag
(UIF)
MS31187V1
1312/2301 RM0432 Rev 6