
REAL-TIME CLOCK
S-3511A
Rev. 1.4_00
14
Seiko Instruments Inc.
2.2 Status register
The status register is an 8-bit register which allows you to display and set various modes. The
POWER flag is read-only and others are read/write-enabled.
B7
LSB
POWER
12/24
R
R/W
INTAE
INTME
MSB
B6
B5
B4
B3
B2
B1
B0
INTFE
-
Figure 11
B7:POWER
This flag turns to "1" if the power voltage detecting circuit operates during
power-on or changes in power voltage (below VDET). Once turning to "1", this
flag does not turns back to "0" even when the power voltage reaches or
exceeds the detection voltage. When the flag is "1", you must send the reset
command (or the status register read command), and turn it to "0". It is a
read-only flag.
B6:12/24
This flag is used to set 12-hour or 24-hour expression.
0 : 12-hour expression
1 : 24-hour expression
B5:INTAE
This flag is used to choose the state of INT pin output with alarm interrupt
output set. Enable this flag after setting alarm time that forms a meeting
condition in the INT register:
0 : Alarm interrupt output is disabled.
1 : Alarm interrupt output is enabled.
B3:INTME
This flag is used to make the output of the INT pin per-minute edge interrupt
or per-minute steady interrupt. To make the output per-minute steady
interrupt, set "1" at INTME and INTFE .
0 : Alarm interrupt or selected frequency steady interrupt output
1 : Per-minute edge interrupt or per-minute steady interrupt output
B1:INTFE
This flag is used to make the output of the INT pin per-minute steady interrupt
output (a period of one minute, 50
% of duty) or selected frequency steady
interrupt. Note that the INT register is considered as the data of
frequency/duty if selected frequency steady interrupt is chosen.
0 : Alarm interrupt or per-minute edge interrupt output
1 : Per-minute steady interrupt or selected frequency steady
interrupt output
B4,B2 and B0:
If having written contents, they are ignored. When they are read, “0” can be
read from them.