STMicroelectronics /STM32U575 /TIM1 /TIM1_SMCR

Slave mode selection When external signals are selected the active edge of the trigger signal (tim_trgi) is linked to the polarity selected on the external input (see Input Control register and Control Register description. Note: The gated mode must not be used if tim_ti1f_ed is selected as the trigger input (TS=00100). Indeed, tim_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 tim_trgo or the tim_trgo2 signals 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.

0 (B_0x0): Slave mode disabled - if CEN = '1’ then the prescaler is clocked directly by the internal clock.

1 (B_0x1): Quadrature encoder mode 1, x2 mode- Counter counts up/down on tim_ti1fp1 edge depending on tim_ti2fp2 level.

2 (B_0x2): Quadrature encoder mode 2, x2 mode - Counter counts up/down on tim_ti2fp2 edge depending on tim_ti1fp1 level.

3 (B_0x3): Quadrature encoder mode 3, x4 mode - Counter counts up/down on both tim_ti1fp1 and tim_ti2fp2 edges depending on the level of the other input.

4 (B_0x4): Reset Mode - Rising edge of the selected trigger input (tim_trgi) reinitializes the counter and generates an update of the registers.

5 (B_0x5): Gated Mode - The counter clock is enabled when the trigger input (tim_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.

6 (B_0x6): Trigger Mode - The counter starts at a rising edge of the trigger tim_trgi (but it is not reset). Only the start of the counter is controlled.

7 (B_0x7): External Clock Mode 1 - Rising edges of the selected trigger (tim_trgi) clock the counter.

8 (B_0x8): Combined reset + trigger mode - Rising edge of the selected trigger input (tim_trgi) reinitializes the counter, generates an update of the registers and starts the counter.

9 (B_0x9): Combined gated + reset mode - The counter clock is enabled when the trigger input (tim_trgi) is high. The counter stops and is reset) as soon as the trigger becomes low. Both start and stop of the counter are controlled.

10 (B_0xA): Encoder mode: Clock plus direction, x2 mode.

11 (B_0xB): Encoder mode: Clock plus direction, x1 mode, tim_ti2fp2 edge sensitivity is set by CC2P

12 (B_0xC): Encoder mode: Directional Clock, x2 mode.

13 (B_0xD): Encoder mode: Directional Clock, x1 mode, tim_ti1fp1 and tim_ti2fp2 edge sensitivity is set by CC1P and CC2P.

14 (B_0xE): Quadrature encoder mode: x1 mode, counting on tim_ti1fp1 edges only, edge sensitivity is set by CC1P.

15 (B_0xF): Quadrature encoder mode: x1 mode, counting on tim_ti2fp2 edges only, edge sensitivity is set by CC2P.

OCREF clear selection This bit is used to select the OCREF clear source.

0 (B_0x0): tim_ocref_clr_int is connected to the tim_ocref_clr input

1 (B_0x1): tim_ocref_clr_int is connected to tim_etrf

Trigger selection - bit 4:3 Refer to TS[2:0] description - bits 6:4 null Trigger selection This bitfield is combined with TS[4:3] bits. This bit-field selects the trigger input to be used to synchronize the counter. others: Reserved See for more details on tim_itrx meaning for each Timer. Note: These bits must be changed only when they are not used (e.g. when SMS=000) to avoid wrong edge detections at the transition.

0 (B_0x0): Internal Trigger 0 (tim_itr0)

1 (B_0x1): Internal Trigger 1 (tim_itr1)

2 (B_0x2): Internal Trigger 2 (tim_itr2)

3 (B_0x3): Internal Trigger 3 (tim_itr3)

4 (B_0x4): tim_ti1 Edge Detector (tim_ti1f_ed)

5 (B_0x5): Filtered Timer Input 1 (tim_ti1fp1)

6 (B_0x6): Filtered Timer Input 2 (tim_ti2fp2)

7 (B_0x7): External Trigger input (tim_etrf)

8 (B_0x8): Internal Trigger 0 (tim_itr4)

9 (B_0x9): Internal Trigger 1 (tim_itr5)

10 (B_0xA): Internal Trigger 1 (tim_itr6)

11 (B_0xB): Internal Trigger 1 (tim_itr7)

12 (B_0xC): Internal Trigger 1 (tim_itr8)

13 (B_0xD): Internal Trigger 1 (tim_itr9)

14 (B_0xE): Internal Trigger 1 (tim_itr10)

Master/slave mode

0 (B_0x0): No action

1 (B_0x1): The effect of an event on the trigger input (tim_trgi) is delayed to allow a perfect synchronization between the current timer and its slaves (through tim_trgo). It is useful if we want to synchronize several timers on a single external event.

External trigger filter This bit-field then defines the frequency used to sample tim_etrp signal and the length of the digital filter applied to tim_etrp. The digital filter is made of an event counter in which N consecutive events are needed to validate a transition on the output:

0 (B_0x0): No filter, sampling is done at fDTS

1 (B_0x1): fSAMPLING=ftim_ker_ck, N=2

2 (B_0x2): fSAMPLING=ftim_ker_ck, N=4

3 (B_0x3): fSAMPLING=ftim_ker_ck, N=8

4 (B_0x4): fSAMPLING=fDTS/2, N=6

5 (B_0x5): fSAMPLING=fDTS/2, N=8

6 (B_0x6): fSAMPLING=fDTS/4, N=6

7 (B_0x7): fSAMPLING=fDTS/4, N=8

8 (B_0x8): fSAMPLING=fDTS/8, N=6

9 (B_0x9): fSAMPLING=fDTS/8, N=8

10 (B_0xA): fSAMPLING=fDTS/16, N=5

11 (B_0xB): fSAMPLING=fDTS/16, N=6

12 (B_0xC): fSAMPLING=fDTS/16, N=8

13 (B_0xD): fSAMPLING=fDTS/32, N=5

14 (B_0xE): fSAMPLING=fDTS/32, N=6

15 (B_0xF): fSAMPLING=fDTS/32, N=8

External trigger prescaler External trigger signal tim_etrp frequency must be at most 1/4 of TIMxCLK frequency. A prescaler can be enabled to reduce tim_etrp frequency. It is useful when inputting fast external clocks on tim_etr_in.

0 (B_0x0): Prescaler OFF

1 (B_0x1): tim_etr_in frequency divided by 2

2 (B_0x2): tim_etr_in frequency divided by 4

3 (B_0x3): tim_etr_in frequency divided by 8

External clock enable This bit enables External clock mode 2. Note: Setting the ECE bit has the same effect as selecting external clock mode 1 with tim_trgi connected to tim_etrf (SMS=111 and TS=00111). It is possible to simultaneously use external clock mode 2 with the following slave modes: reset mode, gated mode and trigger mode. Nevertheless, tim_trgi must not be connected to tim_etrf in this case (TS bits must not be 00111). If external clock mode 1 and external clock mode 2 are enabled at the same time, the external clock input is tim_etrf.

0 (B_0x0): External clock mode 2 disabled

1 (B_0x1): External clock mode 2 enabled. The counter is clocked by any active edge on the tim_etrf signal.

External trigger polarity This bit selects whether tim_etr_in or tim_etr_in is used for trigger operations

0 (B_0x0): tim_etr_in is non-inverted, active at high level or rising edge.

1 (B_0x1): tim_etr_in is inverted, active at low level or falling edge.

Slave mode selection When external signals are selected the active edge of the trigger signal (tim_trgi) is linked to the polarity selected on the external input (see Input Control register and Control Register description. Note: The gated mode must not be used if tim_ti1f_ed is selected as the trigger input (TS=00100). Indeed, tim_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 tim_trgo or the tim_trgo2 signals 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.

0 (B_0x0): Slave mode disabled - if CEN = '1’ then the prescaler is clocked directly by the internal clock.

1 (B_0x1): Quadrature encoder mode 1, x2 mode- Counter counts up/down on tim_ti1fp1 edge depending on tim_ti2fp2 level.

2 (B_0x2): Quadrature encoder mode 2, x2 mode - Counter counts up/down on tim_ti2fp2 edge depending on tim_ti1fp1 level.

3 (B_0x3): Quadrature encoder mode 3, x4 mode - Counter counts up/down on both tim_ti1fp1 and tim_ti2fp2 edges depending on the level of the other input.

4 (B_0x4): Reset Mode - Rising edge of the selected trigger input (tim_trgi) reinitializes the counter and generates an update of the registers.

5 (B_0x5): Gated Mode - The counter clock is enabled when the trigger input (tim_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.

6 (B_0x6): Trigger Mode - The counter starts at a rising edge of the trigger tim_trgi (but it is not reset). Only the start of the counter is controlled.

7 (B_0x7): External Clock Mode 1 - Rising edges of the selected trigger (tim_trgi) clock the counter.

8 (B_0x8): Combined reset + trigger mode - Rising edge of the selected trigger input (tim_trgi) reinitializes the counter, generates an update of the registers and starts the counter.

9 (B_0x9): Combined gated + reset mode - The counter clock is enabled when the trigger input (tim_trgi) is high. The counter stops and is reset) as soon as the trigger becomes low. Both start and stop of the counter are controlled.

10 (B_0xA): Encoder mode: Clock plus direction, x2 mode.

11 (B_0xB): Encoder mode: Clock plus direction, x1 mode, tim_ti2fp2 edge sensitivity is set by CC2P

12 (B_0xC): Encoder mode: Directional Clock, x2 mode.

13 (B_0xD): Encoder mode: Directional Clock, x1 mode, tim_ti1fp1 and tim_ti2fp2 edge sensitivity is set by CC1P and CC2P.

14 (B_0xE): Quadrature encoder mode: x1 mode, counting on tim_ti1fp1 edges only, edge sensitivity is set by CC1P.

15 (B_0xF): Quadrature encoder mode: x1 mode, counting on tim_ti2fp2 edges only, edge sensitivity is set by CC2P.

Trigger selection - bit 4:3 Refer to TS[2:0] description - bits 6:4 null Trigger selection This bitfield is combined with TS[4:3] bits. This bit-field selects the trigger input to be used to synchronize the counter. others: Reserved See for more details on tim_itrx meaning for each Timer. Note: These bits must be changed only when they are not used (e.g. when SMS=000) to avoid wrong edge detections at the transition.

0 (B_0x0): Internal Trigger 0 (tim_itr0)

1 (B_0x1): Internal Trigger 1 (tim_itr1)

2 (B_0x2): Internal Trigger 2 (tim_itr2)

3 (B_0x3): Internal Trigger 3 (tim_itr3)

4 (B_0x4): tim_ti1 Edge Detector (tim_ti1f_ed)

5 (B_0x5): Filtered Timer Input 1 (tim_ti1fp1)

6 (B_0x6): Filtered Timer Input 2 (tim_ti2fp2)

7 (B_0x7): External Trigger input (tim_etrf)

8 (B_0x8): Internal Trigger 0 (tim_itr4)

9 (B_0x9): Internal Trigger 1 (tim_itr5)

10 (B_0xA): Internal Trigger 1 (tim_itr6)

11 (B_0xB): Internal Trigger 1 (tim_itr7)

12 (B_0xC): Internal Trigger 1 (tim_itr8)

13 (B_0xD): Internal Trigger 1 (tim_itr9)

14 (B_0xE): Internal Trigger 1 (tim_itr10)

SMS preload enable This bit selects whether the SMS[3:0] bitfield is preloaded

0 (B_0x0): SMS[3:0] bitfield is not preloaded 

1 (B_0x1): SMS[3:0] preload is enabled

SMS preload source This bit selects whether the events that triggers the SMS[3:0] bitfield transfer from preload to active

0 (B_0x0): The transfer is triggered by the Timer’s Update event

1 (B_0x1): The transfer is triggered by the Index event