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RTC - 8564 JE/NB
• C ( Century bit )
This bit indicates change of century. When the year digit data overflows from 99 to 00, this bit is set. By
presetting it to 0 while still in the 20th century, it will be set in year 2000, but in fact the first year in the 21
century should be 2001.
• Weekdays registers ( Example for allotment of a day. )
Address
06
8.2.4. Alarm registers
Address
09
Minute Alarm
0A
0B
0C
Weekday Alarm
• AE
This is the alarm control bit. There is an MSB for each register of minute alarm, hour alarm, day alarm, and day
of week alarm. When this bit is set to 1, the appropriate register will be set to have the alarm unconditionally
and regardless of the data, and this device is regarded as to have the circuitry working.
When the hour digit and the AE of data are set, alarm will occur at the specified minute regardless of the date
and time. In other words the alarm will occur at the specified minute of every hour. Similarly, when minute and
hour are set to AE, alarm occurs at the specified date. Therefore, by combining them in this way a highly
versatile alarm can be set. When all of the bits are set to AE, no alarm will occur.
Additional information on the alarm function:
Even when the alarm is turned on for a long time, this device clears the flag when the alarm occurs once, and
so no more further alarm will occur under the same condition. This means in the same day when the alarm
condition is met, once the alarm flag is cleared and the alarm becomes unmatched the alarm will not occur
unless new condition is met. Therefore, take note of this when using the flag.
8.2.5. CLKOUT frequency selection and timer registers
Address
0D
CLKOUT frequency
0E
Timer control
0F
• Frequency output
Output
frequency
32768 Hz
1024 Hz
32 Hz
1 Hz
• Timer control
Timer source
clock
4096 Hz
64 Hz
1 second
1 minute
• Timer register
It sets the initial value of the timer's count down. The format is binary.
Function
bit 6
×
×
×
×
Weekdays
×
×
×
Function
bit 7
AE
Hour Alarm
AE
Day Alarm
AE
AE
Function
bit 7
FE
TE
Timer
128
∗ At the above setting, the output frequency of the CLKOUT pin can be
FD1
FD0
0
0
0
1
1
0
1
1
∗ At the above setting, the count down rate of the timer can be
TD1
TD0
0
0
0
1
1
0
1
1
bit 5
bit 4
bit 3
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
×
bit 6
bit 5
bit 4
40
20
10
×
20
10
×
20
10
×
×
×
bit 6
bit 5
bit 4
×
×
×
×
×
×
64
32
16
selected.
Output is possible when the FE of MSB of the D register is 1. (When
it stops, the CLKOUT pin goes to LOW.)
These output is controlled by CLKOE pin. When CLKOE input is
LOW, CLKOUT output is inhibited.
selected.
When the TE of MSB of the E register is 1, the timer count down
starts, and stops when it becomes 0.
The F register data counts down at the set frequency and when it
becomes zero TF is set.
When the F register is read, the data during count down is read out.
Page - 7
bit 2
bit 1
bit 0
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
bit 3
bit 2
bit 1
8
4
8
4
8
4
×
4
bit 3
bit 2
bit 1
×
×
FD1
×
×
TD1
8
4
MQ - 322 - 04
Week
SUN
MON
TUE
WED
THU
FRI
SAT
bit 0
2
1
2
1
2
1
2
1
bit 0
FD0
TD0
2
1
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