s-35190a Seiko Instruments Inc., s-35190a Datasheet - Page 30

• Manufacturer Part Number: s-35190a
• Description: 3-wire Real-time Clock
• Manufacturer: Seiko Instruments Inc.

30
3-WIRE REAL-TIME CLOCK
S-35190A
Serial Interface
The S-35190A receives various commands via 3-wire serial interface to Read/Write data. Regarding transmission is as
follows.
1. Data Read
2. Data Write
3. Data access
When data is input from the SIO pin in synchronization with the falling of the SCK clock after setting the CS pin to “H”, the
data is loaded internally in synchronization with the next rising of the SCK clock. When
eighth rising of the SCK clock, the state of data reading is entered. Data corresponding to each command is then output
in synchronization with the falling of the subsequent SCK clock input. When the SCK clock is less than 8, the IC is in
the clock-wait status, and no processing is performed.
When data is input from the SIO pin in synchronization with the falling of the SCK clock after setting the CS pin to “H”, the
data is loaded internally in synchronization with the next rising of the SCK clock. When
eighth rising of the SCK clock, the state of data writing is entered. In this state, the data, which is input in synchronization
with the falling of the subsequent SCK clock input, is written to registers according to each command. In data Write, input
a clock pulse which is equivalent to the byte of the register. As well as in Read, when the SCK clock is less than 8, the IC
is in the clock-wait status, and no processing is performed.
(1) Real-time data 1 access
SCK
SIO
CS
X
0
1
1
Fixed code +
command
1
0
0
1
0
8
B7
R / W
Year data
Figure 34 Real-Time Data Access 1
During reading: Output mode switching
B0
Seiko Instruments Inc.
16
56
B7
Second data
R
R
During reading:
Input mode switching
/
/
W
W
B0
64
bit = “0” is loaded at the
bit = “1” is loaded at the
Rev.2.4
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