Tim1 Dma/Interrupt Enable Register (Timx_Dier); Table 115. Tim1 Internal Trigger Connection - STMicroelectronics RM0365 Reference Manual

Advanced-control timers (TIM1)
Bits 2:0 SMS: Slave mode selection
When external signals are selected the active edge of the trigger signal (TRGI) is linked to
the polarity selected on the external input (see Input Control register and Control Register
description.
0000: Slave mode disabled - if CEN = '1' then the prescaler is clocked directly by the internal
clock.
0001: Encoder mode 1 - Counter counts up/down on TI1FP1 edge depending on TI2FP2
level.
0010: Encoder mode 2 - Counter counts up/down on TI2FP2 edge depending on TI1FP1
level.
0011: Encoder mode 3 - Counter counts up/down on both TI1FP1 and TI2FP2 edges
depending on the level of the other input.
0100: Reset Mode - Rising edge of the selected trigger input (TRGI) reinitializes the counter
and generates an update of the registers.
0101: Gated Mode - The counter clock is enabled when the trigger input (TRGI) is high. The
counter stops (but is not reset) as soon as the trigger becomes low. Both start and stop of
the counter are controlled.
0110: Trigger Mode - The counter starts at a rising edge of the trigger TRGI (but it is not
reset). Only the start of the counter is controlled.
0111: External Clock Mode 1 - Rising edges of the selected trigger (TRGI) clock the counter.
1000: Combined reset + trigger mode - Rising edge of the selected trigger input (TRGI)
reinitializes the counter, generates an update of the registers and starts the counter.
Codes above 1000: Reserved.
Note: The gated mode must not be used if TI1F_ED is selected as the trigger input (TS=100).
Note: The clock of the slave timer must be enabled prior to receive events from the master
Slave TIM
TIM1
1. TIM1_ITR3 selection is made using bit 6 of the SYSCFG_CFGR1 register.
20.4.4

TIM1 DMA/interrupt enable register (TIMx_DIER)

Address offset: 0x0C
Reset value: 0x0000
15 14 13
Res. TDE COMDE CC4DE CC3DE CC2DE CC1DE
rw rw
521/1080
Indeed, TI1F_ED outputs 1 pulse for each transition on TI1F, whereas the gated mode
checks the level of the trigger signal.
timer, and must not be changed on-the-fly while triggers are received from the master
timer.

Table 115. TIM1 internal trigger connection

ITR0 (TS = 000)
TIM15
12 11 10 9
rw rw rw rw
DocID025202 Rev 7
ITR1 (TS = 001)
TIM2
8 7 6 5
UDE BIE TIE COMIE CC4IE
rw rw rw rw
ITR2 (TS = 010) ITR3 (TS = 011)
TIM3 TIM4 or TIM17
4 3 2
CC3IE CC2IE
rw rw rw
RM0365
(1)
1 0
CC1IE UIE
rw rw