R01UH0823EJ0100 Rev.1.00
Page 782 of 1823
Jul 31, 2019
RX23W Group
28. Realtime Clock (RTCe)
RESET Bit (RTC Software Reset)
This bit initializes the prescaler and registers to be reset by RTC software reset.
When 1 is written to the RESET bit, the initialization starts in synchronization with the count source. When the
initialization is completed, the RESET bit is automatically set to 0.
When 1 is written to the RESET bit, check that the bit is set to 0, and then make next settings.
ADJ30 Bit (30-Second Adjustment)
This bit is for 30-second adjustment.
When 1 is written to the ADJ30 bit, the RSECCNT value of 30 seconds or less is rounded down to 00 second and the
value of 30 seconds or more is rounded up to 1 minute.
The 30-second adjustment is performed in synchronization with the count source. When 1 is written to this bit, the
ADJ30 bit is automatically set to 0 after the 30-second adjustment is completed. In case when 1 is written to the ADJ30
bit, check that the bit is set to 0, and then make next settings.
When the 30-second adjustment is performed, the prescaler and R64CNT are also reset.
The ADJ30 bit is set to 0 by an RTC software reset.
This bit is reserved in binary counter mode. The write value should be 0.
RTCOE Bit (RTCOUT Output Enable)
This bit enables output of a 1-Hz/64-Hz clock signal from the RTCOUT pin.
Use the START bit to stop counting by the counters before changing the value of the RTCOE bit. Do not stop counting
(write 0 to the START bit) and change the value of the RTCOE bit at the same time.
When RTCOUT signal is to be output from an external pin, set the RTCOE bit to 1 and set up the port control for the pin.
AADJE Bit (Automatic Adjustment Enable)
This bit controls (enables or disables) automatic adjustment.
Set the plus–minus bits (RADJ.PMADJ[1:0]) to 00b (adjustment is not performed) before changing the value of the
AADJE bit.
The AADJE bit is set to 0 by an RTC software reset.
AADJP Bit (Automatic Adjustment Period Select)
This bit selects the automatic-adjustment period.
Set the plus–minus bits (RADJ.PMADJ[1:0]) to 00b (adjustment is not performed) before changing the value of the
AADJP bit.
The AADJP bit is set to 0 by an RTC software reset.
This bit specifies whether the RTC will operate in 12- or 24-hour mode.
Use the START bit to stop counting by the counters before changing the value of the HR24 bit. Do not stop counting
(write 0 to the START bit) and change the value of the HR24 bit at the same time.
This bit is reserved in binary counter mode. The write value should be 0.
This bit specifies whether the RTC count mode is operated in calendar count mode or in binary count mode.
When setting the count mode, execute an RTC software reset and start again from the initial settings.
This bit is updated synchronously with the count source, and its value is fixed before the RTC software reset is
completed.
For details on initial settings, refer to
section 28.3.1, Outline of Initial Settings of Registers after Power On