
RM0453 Rev 2
873/1454
RM0453
General-purpose timer (TIM2)
893
26.4.4
TIM2 DMA/Interrupt enable register (TIM2_DIER)
Address offset: 0x0C
Reset value: 0x0000
Bits 16, 2, 1, 0
SMS[3:0]
: 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.
Note: The gated mode must not be used if TI1F_ED is selected as the trigger input
(TS=00100). Indeed, TI1F_ED outputs 1 pulse for each transition on TI1F, whereas the
gated mode checks the level of the trigger signal.
Note: The clock of the slave peripherals (timer, ADC, ...) receiving the TRGO signal must be
enabled prior to receive events from the master timer, and the clock frequency
(prescaler) must not be changed on-the-fly while triggers are received from the master
timer.
Table 183. TIM2 internal trigger connection
Slave TIM
ITR0
ITR1
ITR2 - ITR8
TIM2
TIM1
-
-
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Res.
Res.
Res.
CC4DE CC3DE CC2DE CC1DE
UDE
Res.
TIE
Res.
CC4IE
CC3IE
CC2IE
CC1IE
UIE
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
Bits 15:14 Reserved, must be kept at reset value.
Bit 13 Reserved, must be kept at reset value.
Bit 12
CC4DE
: Capture/Compare 4 DMA request enable
0: CC4 DMA request disabled.
1: CC4 DMA request enabled.
Bit 11
CC3DE
: Capture/Compare 3 DMA request enable
0: CC3 DMA request disabled.
1: CC3 DMA request enabled.