RS5C313 RICOH Co.,Ltd., RS5C313 Datasheet - Page 27

• Manufacturer Part Number: RS5C313
• Description: Ultra-compact Real-time Clock Ic
• Manufacturer: RICOH Co.,Ltd.

(b) Daily Time (Hour or Minute) Alarm Operation*
In the above typical operation, alarm time (hour and minute) is collated with
clock time by making interrupt operation a maximum of 37 times per day as
shown by the following calculation:
23(1-hour digit)+5(10-minute digit)+9(1-minute digit)=37 times
In this connection, a total current consumption increase resulting from inter-
rupt operation can also be calculated as follows:
Assuming, for example, that interrupt operation to the CPU takes 50 ms and
consumes 10mA of current, an average current consumption increase result-
ing from interrupt operation can be calculated as follows: (50 ms
times) / (60 seconds
current consumption of about 0.91µA when the RS5C313 is set to 3V, a total
current consumption can be calculated at about 1.1µA.
Interrupt cycle register ← h
Control register ←2h, 6h
Read from clock counter
Readings match?
Interrupt to CPU
CTFG=1?
YES
YES
×
60 minutes
*
*
3
4
*
NO
NO
2
Interrupt operatin
from any other IC
×
24 hours)=0.21µA Counting in a standard
Note
*
*
*
*
1)
2)
3) Write 2h for the 12-hour format or 6h for the 24-hour format.
4) Collate alarm time with clock time through interrupt operation.
1
In this manner, change the settings of the interrupt cycle register.
Initially set address
In this typical operation, alarm time is stored in the CPU and collated with
clock time through interrupt operation.
sequence for every matching of clock counter readings in
Interrupt Setting
Ch → Bh →
Every Every
1 hour 10 mins. 1 min. (10 secs.
(9h)
(8h)
×
Ch
Bh
Ah
10mA
×
37
h to Ch (every 1 hour) and change it in the following
Every
Ah → (9h →
10-hour and 1-hour digits
10-minute digit (10-hour and 1-hour digits)
1-minute digit
(10-hour, 1-hour, and 10-minute digits)
10-second digit
(10-hour digit to 1-minute digit)
1-second digit
(10-hour digit to 10-second digit)
Time Digit for Collation
(Every
Every)
1 sec.)
8h)
RS5C313
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