GD32F403xx User Manual
365
00: Channel 0 is programmed as output mode
01: Channel 0 is programmed as input mode, IS0 is connected to CI0FE0
10: Channel 0 is programmed as input mode, IS0 is connected to CI1FE0
11: Channel 0 is programmed as input mode, IS0 is connected to ITS
Note:
When CH0MS[1:0]=11, it is necessary to select an internal trigger input
through TRGS bits in TIMERx_SMCFG register.
Input capture mode:
Bits
Fields
Descriptions
15:12
CH1CAPFLT[3:0]
Channel 1 input capture filter control
Refer to CH0CAPFLT description
11:10
CH1CAPPSC[1:0]
Channel 1 input capture prescaler
Refer to CH0CAPPSC description
9:8
CH1MS[1:0]
Channel 1 mode selection
Same as Output compare mode
7:4
CH0CAPFLT[3:0]
Channel 0 input capture filter control
The CI0 input signal can be filtered by digital filter and this bit-field configure the
filtering capability.
Basic principle of digital filter: continuously sample the CI0 input signal according to
f
SAMP
and record the number of times of the same level of the signal. After reaching
the filtering capacity configured by this bit, it is considered to be an effective level.
The filtering capability configuration is as follows:
CH0CAPFLT [3:0]
Times
f
SAMP
4’b0000
Filter disabled.
4’b0001
2
f
CK_TIMER
4’b0010
4
4’b0011
8
4’b0100
6
f
DTS
/2
4’b0101
8
4’b0110
6
f
DTS
/4
4’b0111
8
4’b1000
6
f
DTS
/8
4’b1001
8
4’b1010
5
f
DTS
/16
4’b1011
6
4’b1100
8
4’b1101
5
f
DTS
/32
4’b1110
6
4’b1111
8
3:2
CH0CAPPSC[1:0]
Channel 0 input capture prescaler
This bit-field specifies the factor of the prescaler on channel 0 input. The prescaler