RM0440 Rev 4 1209/2126
RM0440 Advanced-control timers (TIM1/TIM8/TIM20)
1226
Bits 23:20 BK2F[3:0]: Break 2 filter
This bit-field defines the frequency used to sample tim_brk2 input and the length of the digital
filter applied to tim_brk2. The digital filter is made of an event counter in which N consecutive
events are needed to validate a transition on the output:
0000: No filter, tim_brk2 acts asynchronously
0001: f
SAMPLING
=f
tim_ker_ck
, N=2
0010: f
SAMPLING
=f
tim_ker_ck
, N=4
0011: f
SAMPLING
=f
tim_ker_ck
, N=8
0100: f
SAMPLING
=f
DTS
/2, N=6
0101: f
SAMPLING
=f
DTS
/2, N=8
0110: f
SAMPLING
=f
DTS
/4, N=6
0111: f
SAMPLING
=f
DTS
/4, N=8
1000: f
SAMPLING
=f
DTS
/8, N=6
1001: f
SAMPLING
=f
DTS
/8, N=8
1010: f
SAMPLING
=f
DTS
/16, N=5
1011: f
SAMPLING
=f
DTS
/16, N=6
1100: f
SAMPLING
=f
DTS
/16, N=8
1101: f
SAMPLING
=f
DTS
/32, N=5
1110: f
SAMPLING
=f
DTS
/32, N=6
1111: f
SAMPLING
=f
DTS
/32, N=8
Note: This bit cannot be modified when LOCK level 1 has been programmed (LOCK bits in
TIMx_BDTR register).
Bits 19:16 BKF[3:0]: Break filter
This bit-field defines the frequency used to sample tim_brk input and the length of the digital
filter applied to tim_brk. The digital filter is made of an event counter in which N consecutive
events are needed to validate a transition on the output:
0000: No filter, tim_brk acts asynchronously
0001: f
SAMPLING
=f
tim_ker_ck
, N=2
0010: f
SAMPLING
=f
tim_ker_ck
, N=4
0011: f
SAMPLING
=f
tim_ker_ck
, N=8
0100: f
SAMPLING
=f
DTS
/2, N=6
0101: f
SAMPLING
=f
DTS
/2, N=8
0110: f
SAMPLING
=f
DTS
/4, N=6
0111: f
SAMPLING
=f
DTS
/4, N=8
1000: f
SAMPLING
=f
DTS
/8, N=6
1001: f
SAMPLING
=f
DTS
/8, N=8
1010: f
SAMPLING
=f
DTS
/16, N=5
1011: f
SAMPLING
=f
DTS
/16, N=6
1100: f
SAMPLING
=f
DTS
/16, N=8
1101: f
SAMPLING
=f
DTS
/32, N=5
1110: f
SAMPLING
=f
DTS
/32, N=6
1111: f
SAMPLING
=f
DTS
/32, N=8
Note: This bit cannot be modified when LOCK level 1 has been programmed (LOCK bits in
TIMx_BDTR register).