Epson S1C17624 Technical Manual page 88

8 Real-TiMe ClOCK (RTC)
D7 Reserved
D[6:4] RTCMih[2:0]: RTC 10-minute Counter Bits
These bits comprise a 3-bit BCD counter used to count tens of minutes.
The counter counts from 0 to 5 with a carry over of 1 from the 1-minute counter. This counter is reset to
0 after 5 and outputs a carry over of 1 to the 1-hour counter.
D[3:0] RTCMil[3:0]: RTC 1-minute Counter Bits
These bits comprise a 4-bit BCD counter used to count units of minutes.
The counter counts from 0 to 9 with a carry over of 1 from the 10-second counter. This counter is reset
to 0 after 9 and outputs a carry over of 1 to the 10-minute counter.
RTC hour Register (RTC_hOuR)
Register name address Bit
RTC hour 0x5146
D7
Register
(8 bits)
D6
(RTC_hOuR)
D5–4 RTChh[1:0] RTC 10-hour counter
D3–0 RTChl[3:0] RTC 1-hour counter
* Software reset (RTCRST → 1 → 0) does not affect the counter values. This register retains the value set before a software reset is
performed.
notes: • Data should not be read from or written to the counters while 1 is being carried over. (See
Section 8.3.5, "Counter Hold and Busy Flag," and Section 8.3.7, "Counter Read.")
• Rewriting RTC24H/RTC_CNTL0 register may corrupt the count data in this register. Therefore,
after changing the RTC24H setting, be sure to set up this register again.
D7 Reserved
D6 RTCaP: aM/PM indicator Bit
When 12-hour mode is selected, this bit indicates A.M. or P.M.
1 (R/W): P.M.
0 (R/W): A.M.
This bit is only effective when RTC24H/RTC_CNTL0 register is set to 0 (12-hour mode).
When 24-hour mode is selected, this bit is fixed to 0. In this case, do not write 1 to RTCAP.
note: The RTCAP bit keeps the current set value even if RTC24H/RTC_CNTL0 register is changed
from 12-hour mode to 24-hour mode, and will be fixed at 0 after the hour counter is updated (or
reset in software).
D[5:4] RTChh[1:0]: RTC 10-hour Counter Bits
These bits comprise a 2-bit BCD counter used to count tens of hours.
With a carry over of 1 from the 1-hour counter, the counter counts from 0 to 1 when 12-hour mode is
selected, or from 0 to 2 when 24-hour mode is selected. The counter is reset at 12 o'clock or 24 o'clock,
and outputs a carry over of 1 to the 1-day counter.
D[3:0] RTChl[3:0]: RTC 1-hour Counter Bits
These bits comprise a 4-bit BCD counter used to count units of hours.
The counter counts from 0 to 9 with a carry over of 1 from the 10-minute counter. This counter is reset
to 0 after 9 and outputs a carry over of 1 to the 10-hour counter. Depending on whether 12-hour mode
or 24-hour mode is selected, the counter is reset at 12 o'clock or 24 o'clock.
RTC Day Register (RTC_DaY)
Register name address Bit
RTC Day 0x5147 D7–6 –
Register
(8 bits) D5–4 RTCDh[1:0] RTC 10-day counter
(RTC_DaY)
D3–0 RTCDl[3:0] RTC 1-day counter
* Software reset (RTCRST → 1 → 0) does not affect the counter values. This register retains the value set before a software reset is
performed.
8-14
name Function
–
reserved
RTCaP
AM/PM indicator
name Function
reserved
Seiko epson Corporation
Setting init. R/W
–
1 PM 0 AM X (*) R/W
0 to 2 or 0 to 1 X (*) R/W
0 to 9 X (*) R/W
Setting init. R/W
–
0 to 3 X (*) R/W
0 to 9 X (*) R/W
S1C17624/604/622/602/621 TeChniCal Manual
Remarks
– – 0 when being read.
Remarks
– – 0 when being read.