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The figure below is Timing Diagram when Division Factor is 1 or 2 in
Center-aligned Mode
Figure 63 Timing Diagram when Division Factor is 1 or 2 in Center-aligned Mode
CNT_EN
CK_CNT
04
03
02
01
00
01
02
03
04
03
02
01
Counter register
Counter underrun
Counter overrun
CK_PSC
PSC=1
CK_CNT
00
01
0003
0002
0001
0000
0001
0002
0003
Counter overrun
Update event
PSC=2
Counter register
Update event
Prescaler PSC
The prescaler is 16 bits and programmable, and it can divide the clock frequency
of the counter to any value between 1 and 65536 (controlled by TMRx_PSC
register), and after frequency division, the clock will drive the counter CNT to
count. The prescaler has a buffer, which can be changed during running.
Input Capture
Input capture channel
The general-purpose timer has four independent capture/compare channels,
each of which is surrounded by a capture/compare register.
In the input capture, the measured signal will enter from the external pin T1/2/3/4
of the timer, first pass through the edge detector and input filter, and then into the
capture channel. Each capture channel has a corresponding capture register.
When the capture occurs, the value of the counter CNT will be latched in the
capture register CCx. Before entering the capture register, the signal will pass
through the prescaler, which is used to set how many events to capture at a time.