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GD32F403xx User Manual
315
Figure 16-36. Timing chart of center-aligned counting mode
Hardware set
Software clear
CEN
PSC_CLK
CNT_REG
3
2
1
0
1
2
.
98
99
98
1
0
Underflow
Overflow
TIMERx_CTL0 CAM = 2'b11
TIMER_CK
1
2
.
98
99
98
97
UPIF
CHxIF
CHxIF
TIMERx_CTL0 CAM = 2'b10 (upcount only
)
TIMERx_CTL0 CAM = 2'b10 (downcount only
)
CHxIF
CHxCV=2
2
1
2
Input capture and output compare channels
The general level0 Timer has four independent channels which can be used as capture inputs
or compare match outputs. Each channel is built around a channel capture compare register
including an input stage, channel controller and an output stage.
◼
Channel input capture function
Channel input capture f unction
allows the channel to perform measurements such as pulse
timing, frequency, period, duty cycle and so on. The input stage consists of a digital filter, a
channel polarity selection, edge detection and a channel prescaler. When a selected edge
occurs on the channel input, the current value of the counter is captured into the
TIMERx_CHxCV register, at the same time the CHxIF bit is set and the channel interrupt is
generated if enabled by CHxIE = 1.