Control Registers; Rtc Control Register - Epson S1C17F13 Technical Manual

14.6

Control Registers

RTC Control Register

Register name Bit
RTCCTL 15–9 –
8
7–6 –
5
4
3–1 –
0
Bits 15–9 Reserved
Bit 8 RTCST
This bit indicates the RTC operating status.
1 (R): Running
0 (R): Stop
The RTCCTL.RTCST bit goes 1 when the RTC starts counting by writing 1 to the RTCCTL.RTCRUN
bit and it reverts to 0 when the count operation is actually stopped after 0 is written to the RTCCTL.
RTCRUN bit. When setting counter values, write 0 to the RTCCTL.RTCRUN bit and make sure that
the RTCCTL.RTCST bit is cleared to 0 before writing data.
Bits 7–6 Reserved
Bit 5 BCDMD
This bit sets the second, minute, and hour counters into binary or BCD mode.
1 (R/W): BCD mode
0 (R/W): Binary mode
See "RTC Counters" for the configuration of the counter in each mode.
Bit 4 RTC24h
This bit sets the hour counter to 24H mode or 12H mode.
1 (R/W): 12H mode
0 (R/W): 24H mode
This selection changes the count range of the hour counter. Note, however, that the counter value is
not updated automatically, therefore, it must be programmed again.
Note: Be sure to avoid writing to this bit when the RTCCTL.RTCRUN bit = 1.
Bits 3–1 Reserved
Bit 0 RTCRun
This bit starts/stops the RTC.
1 (R/W): Start
0 (R/W): Stop
When the RTC stops counting by writing 0 to this bit, the counter retains the value when it was
stopped. Writing 1 to this bit again resumes counting from the value retained.
Writing 1 to the RTCCTL.RTCRUN bit resets the OSC1A divider in the clock generator.
S1C17F13 TeChniCal Manual
(Rev. 1.0)
Bit name Initial
0x00
RTCST 0
0x0
BCDMD 0
RTC24H 0
0x0
RTCRUN 0
Seiko epson Corporation
14 REAL-TIME CLOCK (RTC)
Reset R/W
– R –
H0 R
– R
H0 R/W
H0 R/W
– R
H0 R/W
Remarks
14-5