DocID018909 Rev 11
567/1731
RM0090
Advanced-control timers (TIM1&TIM8)
581
Input capture mode
Bits 1:0
CC1S
: Capture/Compare 1 selection
This bit-field defines the direction of the channel (input/output) as well as the used input.
00: CC1 channel is configured as output
01: CC1 channel is configured as input, IC1 is mapped on TI1
10: CC1 channel is configured as input, IC1 is mapped on TI2
11: CC1 channel is configured as input, IC1 is mapped on TRC. This mode is working only if
an internal trigger input is selected through TS bit (TIMx_SMCR register)
Note: CC1S bits are writable only when the channel is OFF (CC1E = ‘0’ in TIMx_CCER).
Bits 15:12
IC2F
:
Input capture 2 filter
Bits 11:10
IC2PSC[1:0]
: Input capture 2 prescaler
Bits 9:8
CC2S
: Capture/Compare 2 selection
This bit-field defines the direction of the channel (input/output) as well as the used input.
00: CC2 channel is configured as output
01: CC2 channel is configured as input, IC2 is mapped on TI2
10: CC2 channel is configured as input, IC2 is mapped on TI1
11: CC2 channel is configured as input, IC2 is mapped on TRC. This mode is working only if an
internal trigger input is selected through TS bit (TIMx_SMCR register)
Note: CC2S bits are writable only when the channel is OFF (CC2E = ‘0’ in TIMx_CCER).
Bits 7:4
IC1F[3:0]
:
Input capture 1 filter
This bit-field defines the frequency used to sample TI1 input and the length of the digital filter applied
to TI1. 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, sampling is done at f
DTS
0001: f
SAMPLING
=f
CK_INT
, N=2
0010: f
SAMPLING
=f
CK_INT
, N=4
0011: f
SAMPLING
=f
CK_INT
, 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
Bits 3:2
IC1PSC
:
Input capture 1 prescaler
This bit-field defines the ratio of the prescaler acting on CC1 input (IC1).
The prescaler is reset as soon as CC1E=’0’ (TIMx_CCER register).
00: no prescaler, capture is done each time an edge is detected on the capture input
01: capture is done once every 2 events
10: capture is done once every 4 events
11: capture is done once every 8 events