rs5c338a RICOH Co.,Ltd., rs5c338a Datasheet - Page 36

• Manufacturer Part Number: rs5c338a
• Description: 3-wire Serial Interface Real-time Clock Ics With Voltage Monitoring Function
• Manufacturer: RICOH Co.,Ltd.

36
R
4.2 Periodic Interrupt
Setting of the periodic selection bits (CT
modes: pulse mode and level mode. In the pulse mode, the output has a waveform duty cycle of around 50%. In the
level mode, the output is cyclically driven low and, when the CTFG bit is set to 0, the output is set to high (OFF).
1) Pulse Mode : 2-Hz and 1-Hz clock pulses are output in synchronization with the increment of the second counter
2) Level Mode : periodic interrupt signals are output with selectable interrupt cycle settings of 1 second, 1 minute, 1
3) When the oscillation adjustment circuit is used, the interrupt cycle will fluctuate once per 20 seconds as follows:
Waveform Mode, Cycle and Falling Timing
CT
×
0
0
0
0
1
1
1
1
Pulse Mode : the “L” period of output pulses will increment or decrement by a maximum of ±3.784ms.
Level Mode : a periodic interrupt cycle of 1 second will increment or decrement by a maximum of ±3.784ms.
5C338A
2
CT
0
0
1
1
0
0
1
1
1
CT
0
1
0
1
0
1
0
1
as illustrated in the timing chart on the next page.
hour, and 1 month. The increment of the second counter is synchronized with the falling edge of
periodic interrupt signals. For example, periodic interrupt signals with an interrupt cycle setting of
1 second are output in synchronization with the increment of the second counter as illustrated in
the timing chart on the next page.
For example, 1-Hz clock pulses will have a duty cycle of 50 ±0.3784%.
0
Pulse Mode
Pulse Mode
Level Mode
Level Mode
Level Mode
Level Mode
Waveform mode
—
—
*
*
*
*
*
*
2
2
2
2
1
1
Off (“H”)
Fixed at low (“L”)
2Hz (Duty cycle of 50%)
1Hz (Duty cycle of 50%)
Once per 1 second (Synchronized with second counter increment)
Once per minute (at 00 seconds of every minute)
Once per hour (at 00 minutes and 00 seconds of every hour)
Once per month (at 00 hours, 00 minutes, and 00 seconds of first day of every month)
2
to CT
0
) enables periodic interrupt to the CPU. There are two waveform
Description
Cycle and falling timing
(Default setting)