FOR AUTOMOTIVE 105°C OPERATION 2-WIRE REAL-TIME CLOCK

S-35390A H Series

Seiko Instruments Inc.

11

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Configuration of Registers

1. Real-time data register

The real-time data register is a 7-byte register that stores the data of year, month, day, day of the week, hour, minute,

and second in the BCD code. To write / read real-time data 1 access, transmit / receive the data of year in B7, month,

day, day of the week, hour, minute, second in B0, in 7-byte. When you skip the procedure to access the data of year,

month, day, day of the week, read / write real-time data 2 accesses. In this case, transmit / receive the data of hour in B7,

minute, second in B0, in 3-byte.

The S-35390A H Series transfers a set of data of time to the real-time data register when it recognizes a reading

instruction. Therefore, the S-35390A H Series keeps precise time even if time-carry occurs during the reading operation

of the real-time data register.

Year data (00 to 99)

Month data (01 to 12)

Day data (01 to 31)

Hour data (00 to 23 or 00 to 11)

Minute data (00 to 59)

Second data (00 to 59)

Y80

Y40

Y4

Y8

Y10

Y20

Y2

Y1

B7

B0

M1

M2

M4

M8

M10

0

0

0

D1

D2

D4

D8

D10

D20

0

0

W1

W2

W4

0

0

0

0

0

H1

H4

H8

H10

H20

H2

0

m1

s2

s4

s8

s10

s20

s40

0

m8

m10

m20

m40

0

m4

m2

AM / PM

s1

Start bit of real-time data 2 data access

Start bit of real-time data 1 data access

Day of the week data (00 to 06)

B7

B0

B7

B0

B7

B0

B7

B0

B7

B0

B7

B0

Figure 10 Real-Time Data Register