S-35392A Datasheet, PDF (21/47 Pages) Seiko Instruments Inc – 2-WIRE REAL-TIME CLOCK

Rev.1.3_00
2-WIRE REAL-TIME CLOCK
S-35392A
„ Alarm 1 Function and INT2 Pin Output Mode
In the output mode for INT2 pin, users are able to select the output;
alarm 2 interrupt, user-set frequency, per-minute edge interrupt, minute-periodical interrupt. To switch the output mode for
INT2 pin and the alarm 1 function, use the status register 2. Refer to 3. Status register 2 in “„ Configuration of
Register”.
When switching the output mode for INT2 pin, be careful of the output status of the pin. Especially, when using alarm 2
interrupt output, or the output of user-set frequency, switch the output mode after setting “00h” in the INT2 register. In
per-minute edge interrupt output/minute-periodical interrupt output, it is unnecessary to set data in the INT2 register for
users.
Refer to the followings regarding each operation of output modes.
1. Alarm 1 function and alarm 2 interrupt
Alarm 2 interrupt output is the function to set the INT2 flag “H” by the output “L” from the INT2 pin, at the alarm time
which is set by user has come. If setting the pin output to “H”, turn off the alarm function by setting “0” in INT2AE in the
status register 2.
By Read, the INT2 flag is once cleared automatically. In the alarm 1 function, the INT1 flag (B3 in the status register1) is
set to “H” when the set time has come. The INT1 flag is also cleared once by Read.
In the alarm 1 function, set the data of day of the week, hour, minute of the alarm time in the INT1 register. In alarm 2
interrupt, set in the INT2 register. Refer to “4. INT1 register and INT2 register” in “„ Configuration of Register”.
Alarm setting of “W (day of the week), H (hour), m (minute)”
Status register 2 setting
• Alarm 1 function
INT1ME = INT1FE = 0
• Alarm 2 interrupt
INT2ME = INT2FE = 0
INT1 register
INT2 register
INTx register alarm enable flag
• AxHE = AxmE = AxWE = "1"
mx Hx Wx
Alarm 1 output
(B3 in status register 1)
Comparator
Second Minute
Hour
Day of
the week
Day Month Year
Alarm 2 interrupt (INT2 pin)/
alarm 2 output
(B2 in status register 1)
Real-time data
W (day of the week)
Real-time data H h (m − 1) m 59 s
H h 00 m 00 s 01 s
59 s _{H h (m + 1) m 00 s}
Change by program
Change by program _{Change by program}
INT1AE/INT2AE
INT1 flag/
INT2 flag
INT2 pin
Alarm time matches
Alarm time matches
OFF
Status register 1 reading
*1
Period when alarm time matches
*1. If users clear INT2AE once; “L” is not output from the INT2 pin by setting INT2AE enable again, within a period when
the alarm time matches real-time data.
Figure 22 Alarm Interrupt Output Timing (1/2)
Seiko Instruments Inc.
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