RV5C339A_03 Datasheet, PDF (17/46 Pages) RICOH electronics devices division – 3-WIRE SERIAL INTERFACE REAL-TIME CLOCK IC WITH VOLTAGE MONITORING FUNCTION

RV5C339A
2.4 Day-of-week Counter (at Address 3h)
D7
D6
D5
D4
D3
—
—
—
—
—
0
0
0
0
0
0
0
0
0
0
D2
D1
D0
W4
W2
W1
(For writing)
W4
W2
W1
(For reading)
Indefinite Indefinite Indefinite Default settings*
*^{) Default settings: Default value means read/written values when the XSTP bit is set to “1” due to power-on from 0 volts or supply voltage drop.}
· The day-of-week counter is incremented by 1 when the day-of-week digits are carried to the day-of-month digits.
· Day-of-week display (incremented in septimal notation):
(W4, W2, W1) = (0, 0, 0) → (0, 0, 1) →^...→ (1, 1, 0) → (0, 0, 0)
· Correspondences between days of the week and the day-of-week digits are user-definable (e.g. Sunday = 0, 0, 0)
· The writing of (1, 1, 1) to (W4, W2, W1) is prohibited except when days of the week are unused.
2.5 Calendar Counters (at Address 4h to 6h)
· The calendar counters are configured to display the calendar digits in BCD format by using the automatic calen-
dar function as follows:
The day-of-month digits (D20 to D1) range from 1 to 31 for January, March, May, July, August, October, and
December; from 1 to 30 for April, June, September, and November; from 1 to 29 for February in leap years;
from 1 to 28 for February in ordinary years.
The day-of-month digits are carried to the month digits in reversion from the last day of the month to 1. The
month digits (MO10 to MO1) range from 1 to 12 and are carried to the year digits in reversion from 12 to 1.
The year digits (Y80 to Y1) range from 00 to 99 (00, 04, 08, ... , 92, and 96 in leap years) and are carried to the
19/20 digits in reversion from 99 to 00.
The 19/20 digits cycle between 0 and 1 in reversion from 99 to 00 in the year digits.
· Any carry from lower digits with the writing of non-existent calendar data may cause the calendar counters to mal-
function. Therefore, such incorrect writing should be replaced with the writing of existent calendar data.
2.5-1 Day-of-month Counter (at Address 4h)
D7
D6
D5
D4
D3
D2
D1
D0
—
—
D20
D10
D8
D4
D2
D1
(For writing)
0
0
D20
D10
D8
D4
D2
D1
(For reading)
0
0
Indefinite Indefinite Indefinite Indefinite Indefinite Indefinite Default settings*
2.5-2 Month Counter + Century Bit (at Address 5h)
D7
D6
19/20
—
D5
D4
D3
D2
D1
D0
—
MO10
MO8
MO4
MO2
MO1 (For writing)
19/20
0
0
MO10
MO8
MO4
MO2
MO1 (For reading)
Indefinite
0
0
Indefinite Indefinite Indefinite Indefinite Indefinite Default settings*
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