S-35390A Seiko Instruments, S-35390A Datasheet - Page 11

• Manufacturer Part Number: S-35390A
• Description: 2-Wire Real Time Clock
• Manufacturer: Seiko Instruments

Rev.1.2
2. Status register_1
shown below.
Status register_1 is an 8-bit register that is used to display and set various modes. The bit configuration is
MSB
_00
B7: POC
B6: BLD
B5, B4: INT2, INT1
B3, B2: SC1, SC0
B1:
B0: RESET
12/24
POC
B7
R
This flag is used to set 12-hour or 24-hour expression.
This flag is set to “1” at power-on. Once this flag is set to “1”, it is not set to “0” even
when the power supply voltage reaches or exceeds the detection voltage (V
flag is read-only and can be read by the status register_1 access command. Once it is
read, it is automatically set to “0”. When the flag is “1”, it must be initialized. For the
method of initialization, refer to “ Initialization at Power-on and Power-on Detector ”.
If the power supply voltage detector detects a voltage of detection voltage (V
less this flag is set to “1”, which enables the detection of a power supply voltage drop.
Once this flag is set to “1”, it is not set to “0” even when the power supply voltage
reaches or exceeds the detection voltage (V
read by the status register_1 access command. Once it is read, it is automatically set
to “0”. When the flag is “1”, it must be initialized. For the method of initialization, refer
to “ Initialization at Power-on and Power-on Detector ”, and for the operation of the
power supply voltage detector, refer to “ Power Supply Voltage Detector ”.
When the interrupt signal is output from the INT1 or INT2 pin using the alarm
interrupt function, for an interrupt signal output from the INT1 pin, the INT1 flag is set
to “1”, and for an interrupt signal output from the INT2 pin, the INT2 flag is set to “1”.
These flags configure a 2-bit SRAM type register that can be freely set by users. They
are read and written within the operating voltage range (1.3 to 5.5 V).
By setting this bit to “1”, the internal IC is initialized. This is a write-only bit and is
always “0” when it is read. Be sure to write “1” to the reset flag when applying the
power supply voltage to the IC.
BLD
B6
R
0: 12-hour expression
1: 24-hour expression
INT2
B5
R
Figure 9 Status Register_1
Seiko Instruments Inc.
INT1
B4
R
R/W
SC1
B3
SC0
R/W
B2
R:
W:
R/W:
DET
). This flag is read-only and can be
2-WIRE REAL-TIME CLOCK
Read-enabled
Write-enabled
Read/write-enabled
12/24
R/W
B1
RESET
B0
W
S-35390A
LSB
DET
DET
). This
) or
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