RS5C348A RICOH Co.,Ltd., RS5C348A Datasheet - Page 18

• Manufacturer Part Number: RS5C348A
• Description: 4-wire Serial Interface Real-time Clock
• Manufacturer: RICOH Co.,Ltd.

Rx5C348A/B
Rev.2.01
Day-of-month Counter (Address 4h)
Month Counter + Century Bit (Address 5h)
Year Counter (Address 6h)
Indefinite
Indefinite
Calendar Counter (Address 4-6h)
Oscillation Adjustment Register (Address 7h)
D7
-
0
0
D7
/19⋅20
/19⋅20
D7
Y80
Y80
D7
(0)
(0)
0
12345
*) Default settings: Default value means read / written values when the XSTP bit is set to “1” due to VDD
*
*
*) Default settings: Default value means read / written values when the XSTP bit is set to “1” due to VDD
(0) bit
The (0) bit should be set to 0 to allow writing to the Oscillation Adjustment Register. The (0) bit will be set
to 0 when the XSTP bit is set to 1 in the Control Register 2.
F6 to F0 bits
The Oscillation Adjustment Circuit is configured to change time counts of 1 second on the basis of the
settings of the Oscillation Adjustment Register when the second digits read 00, 20, or 40 seconds.
Normally, the Second Counter is incremented once per 32768 32.768-kHz clock pulses generated by the
crystal oscillator. Writing to the F6 to F0 bits activates the oscillation adjustment circuit.
* The Oscillation Adjustment Circuit will not operate with the same timing (00, 20, or 40 seconds) as the
timing of writing to the Oscillation Adjustment Register.
* The F6 bit setting of 0 causes an increment of time counts by ((F5, F4, F3, F2, F1, F0) - 1) x 2.
The F6 bit setting of 1 causes a decrement of time counts by ((/F5, /F4, /F3, /F2, /F1, /F0) + 1) x 2.
The settings of "*, 0, 0, 0, 0, 0, *" ("*" representing either "0" or "1") in the F6, F5, F4, F3, F2, F1, and F0 bits
The calendar counters are configured to display the calendar digits in BCD format by using the
automatic calendar 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 malfunction. Therefore, such incorrect writing should be replaced with the writing of
existent calendar data.
Indefinite
D6
-
0
0
D6
-
0
0
D6
Y40
Y40
D6
F6
F6
0
Indefinite
Indefinite
D5
D20
D20
D5
-
0
0
D5
Y20
Y20
D5
F5
F5
0
power-on from 0v or oscillation stopping
power-on from 0v or oscillation stopping
Indefinite
Indefinite
Indefinite
D4
D10
D10
D4
MO10
MO10
D4
Y10
Y10
D4
F4
F4
0
Indefinite
Indefinite
Indefinite
D3
D8
D8
D3
MO8
MO8
D3
Y8
Y8
D3
F3
F3
0
Indefinite
Indefinite
Indefinite
D2
D4
D4
D2
MO4
MO4
D2
Y4
Y4
D2
F2
F2
0
- 18 -
Indefinite
Indefinite
Indefinite
D1
D2
D2
D1
MO2
MO2
D1
Y2
Y2
D1
F1
F1
0
Indefinite
Indefinite
Indefinite
D1
D0
D1
D0
MO1
MO1
D0
Y1
Y1
D0
F0
F0
0
(For Writing)
(For Reading)
Default Settings *)
Default Settings *)
Default Settings *)
(For Writing)
Default Settings *)
(For Writing)
(For Reading)
(For Writing)
(For Reading)
(For Reading)