R01UH0823EJ0100 Rev.1.00
Page 800 of 1823
Jul 31, 2019
RX23W Group
28. Realtime Clock (RTCe)
28.3.8.5
Capturing the Time
The RTC is capable of storing the month, date, hour, minute and second/binary counters 3 to 0 by detecting an edge of a
signal on a time capture event input pin.
A noise filter can also be used on a time capture event input pin. If the noise filter is enabled, the TCST bit is set to 1
when the input level on the pin matches three times.
The noise filter can be switched on or off for each of the time capture event input pins. Operation when the noise filter is
off is shown in
and operation when the noise filter is on is shown in
.
Figure 28.9
Timing of a Time Capture Operation (with the Filter Off) (n = 0, 1)
Figure 28.10
Timing of a Time Capture Operation (with the Filter On) (n = 0, 1)
Count source
RTCICn
Time counters
AAAA
Capture register
0
AAAA
TCST
BBBB
No capturing when
TCST = 1
Internal event-input signal
Detection of the
rising edge
Count source
RTCICn
Time counters
AAAA
Capture register
0
TCST
BBBB
Internal event-input signal
Detection of the rising edge
Since the level has matched three
times, it is conveyed to the internal
circuits.
(1)
(2)
(3)
(1)
(2)
(1)
(2)
BBBB
Since the level has only matched
twice, it is not conveyed to the
internal circuits.
Internal event-detection signal