S-35390A Seiko Instruments, S-35390A Datasheet - Page 28

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

28
2-WIRE REAL-TIME CLOCK
S-35390A
6. Data writing
real-time write command and update operations are then prohibited. Subsequently, when minute data
reception is completed, an end-of-month correction is performed while the second data is loaded.
Counting up is started from the rising of the ACK signal after the second data reception.
After detecting the start condition from outside, a device code and command are received. If the read/write
bit is “0” at this point, the real-time data write mode or another register write mode is entered. Input the
data input sequence for both the real-time data write mode and status register write mode from the LSB.
In real-time data writing, the calendar and time counter is reset by the rising of the ACK signal after the
(1) Real-time data access 1
(2) Real-time data access 2
SDA
SDA
SCL
SCL
*1.
*2.
*1.
*2.
I/O mode switching
I/O mode switching
0
0
MSB
MSB
During reading, set NO_ACK to 1.
During reading, transmit ACK = 0 to S-35390A from the master device.
During reading, set NO_ACK to 1.
During reading, transmit ACK = 0 to S-35390A from the master device.
1
1
1
1
Command
Command
1
1
0
0
0
0
1
1
LSB
LSB
1
0
R/W
R/W
LSB
9
9
LSB
Figure 26 Real-time Data Access 1
Figure 27 Real-time Data Access 2
Hour data
Year data
Seiko Instruments Inc.
MSB
MSB
I/O mode switching
I/O mode switching
LSB
LSB
Second data
Second data
MSB
MSB
72
36
Rev.1.2
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