10 REAL-TIME CLOCK (RTCA)
10-12
Seiko Epson Corporation
S1C31D50/D51 TECHNICAL MANUAL
(Rev. 2.00)
Table 10.6.2 Correspondence between the count value and day of the week
RTCAYAR.RTCWK[2:0] bits
Day of the week
0x6
Saturday
0x5
Friday
0x4
Thursday
0x3
Wednesday
0x2
Tuesday
0x1
Monday
0x0
Sunday
Note: Be sure to avoid writing to the RTCAYAR.RTCWK[2:0] bits while the RTCACTLL.RTCBSY bit
= 1.
Bits 7–4
RTCYH[3:0]
Bits 3–0
RTCYL[3:0]
The RTCAYAR.RTCYH[3:0] bits and the RTCAYAR.RTCYL[3:0] bits are used to set and read the
10-year digit and the 1-year digit of the year counter, respectively. The setting/read values are a BCD
code within the range from 0 to 99.
Note: Be sure to avoid writing to the RTCAYAR.RTCYH[3:0]/RTCYL[3:0] bits while the RTCACTLL.
RTCBSY bit = 1.
RTCA Interrupt Flag Register
Register name
Bit
Bit name
Initial
Reset
R/W
Remarks
RTCAINTF
15 RTCTRMIF
0
H0
R/W Cleared by writing 1.
14 SW1IF
0
H0
R/W
13 SW10IF
0
H0
R/W
12 SW100IF
0
H0
R/W
11–9 –
0x0
–
R
–
8
ALARMIF
0
H0
R/W Cleared by writing 1.
7
T1DAYIF
0
H0
R/W
6
T1HURIF
0
H0
R/W
5
T1MINIF
0
H0
R/W
4
T1SECIF
0
H0
R/W
3
T1_2SECIF
0
H0
R/W
2
T1_4SECIF
0
H0
R/W
1
T1_8SECIF
0
H0
R/W
0
T1_32SECIF
0
H0
R/W
Bit 15
RTCTRMIF
Bit 14
SW1IF
Bit 13
SW10IF
Bit 12
SW100IF
These bits indicate the real-time clock interrupt cause occurrence status.
1 (R):
Cause of interrupt occurred
0 (R):
No cause of interrupt occurred
1 (W):
Clear flag
0 (W):
Ineffective
The following shows the correspondence between the bit and interrupt:
RTCAINTF.RTCTRMIF bit: Theoretical regulation completion interrupt
RTCAINTF.SW1IF bit:
Stopwatch 1 Hz interrupt
RTCAINTF.SW10IF bit:
Stopwatch 10 Hz interrupt
RTCAINTF.SW100IF bit: Stopwatch 100 Hz interrupt
Bits 11–9 Reserved