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RX − 8801 SA / JE
8.2.8. Calendar counter (Reg 4 to 6)
Address
4
5
6
∗)
"o" indicates write-protected bits. A zero is always read from these bits.
• The auto calendar function updates all dates, months, and years from January 1, 2001 to December 31, 2099.
• The data format is BCD format. For example, a date register value of "0011 0001" indicates the 31st.
∗ Note with caution that writing non-existent date data may interfere with normal operation of the calendar counter.
1) Date counter
Address
4
• The updating of dates by the date counter varies according to the month setting.
∗ A leap year is set whenever the year value is a multiple of four (such as 04, 08, 12, 88, 92, or 96). In
February of a leap year, the counter counts dates from "01," "02," "03," to "28," "29," "01," etc.
2) Month counter
Address
5
• The month counter counts from 01 (January), 02 (February), and up to 12 (December), then starts again at
01 (January).
3) Year counter
Address
6
• The year counter counts from 00, 01, 02 and up to 99, then starts again at 00.
• Any year that is a multiple of four (04, 08, 12, 88, 92, 96, etc.) is handled as a leap year.
8.2.9. Alarm registers (Reg - 8 ∼ A)
Address
8
MIN Alarm
9
HOUR Alarm
WEEK Alarm
A
DAY Alarm
• The alarm interrupt function is used, along with the AEI, AF, and WADA bits, to set alarms for specified date, day,
hour, and minute values.
• When the settings in the above alarm registers and the WADA bit match the current time, the /INT pin goes to low
level and "1" is set to the AF bit to report that and alarm interrupt event has occurred.
8.2.10. Fixed-cycle timer control registers (Reg - B to C)
Address
B
Timer Counter 0
C
Timer Counter 1
• These registers are used to set the preset countdown value for the fixed-cycle timer interrupt function.
The TE, TF, TIE, and TSEL0/1 bits are also used to set the fixed-cycle timer interrupt function.
• When the value in the above fixed-cycle timer control register changes from 001h to 000h, the /INT pin goes to low
level and "1" is set to the TF bit to report that a fixed-cycle timer interrupt event has occurred.
Function
bit 7
DAY
MONTH
YEAR
80
Function
bit 7
DAY
DAY
1, 3, 5, 7, 8, 10, or 12
4, 6, 9, or 11
Write/Read
February in normal year
February in leap year
Function
bit 7
MONTH
Function
bit 7
Years
Y80
Function
bit 7
AE
AE
AE
Function
bit 7
128
•
bit 6
bit 5
bit 4
20
10
10
40
20
10
bit 6
bit 5
bit 4
20
10
Month
bit 6
bit 5
bit 4
10
bit 6
bit 5
bit 4
Y40
Y20
Y10
bit 6
bit 5
bit 4
40
20
10
•
20
10
6
5
4
•
20
10
bit 6
bit 5
bit 4
64
32
16
•
•
•
Page - 13
bit 3
bit 2
bit 1
8
4
2
8
4
2
8
4
2
bit 3
bit 2
bit 1
8
4
2
Date update pattern
01, 02, 03 ∼ 30, 31, 01 ∼
01, 02, 03 ∼ 30, 01, 02 ∼
01, 02, 03 ∼ 28, 01, 02 ∼
01, 02, 03 ∼ 28, 29, 01 ∼
bit 3
bit 2
bit 1
8
4
2
bit 3
bit 2
bit 1
Y8
Y4
Y2
bit 3
bit 2
bit 1
8
4
2
8
4
2
3
2
1
8
4
2
bit 3
bit 2
bit 1
8
4
2
2048
1024
512
ETM26E-03
bit 0
1
1
1
bit 0
1
bit 0
1
bit 0
Y1
bit 0
1
1
0
1
bit 0
1
256
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