s-35399a03 Seiko Instruments Inc., s-35399a03 Datasheet - Page 31

• Manufacturer Part Number: s-35399a03
• Description: 2-wire Real-time Clock
• Manufacturer: Seiko Instruments Inc.

Clock pulse
of real-time
second data
"00h"
24-bit binary
Power supply
Rev.1.0
up counter
Up-Count Operation
The up counter is a 24-bit read-only binary counter. This counter starts counting from “000000h” from power-on and returns
to “000000h” at the next clock after it has reached “FFFFFFh”. A clock pulse is a pulse that is output when the second-data
in the real-time data is “00h”. Therefore, some delay is made in the period that a clock pulse is being output due to Write
timing and Write data. The registers are not initialized unless power-on again, so that users are able to grasp the elapsed
time from power-on up to 30 years. Figure 32 shows the example of timing chart of up counter’s operation.
_00
OFF
60 seconds or more.
A clock pulse is
Write real-time
ON
second data:
40 s
20 seconds
000000 h
40 s
Figure 32 Timing Chart of 24-Bit Binary Up Counter
000001 h 000010 h
60 s
60 seconds or less.
A clock pulse is
Write real-time
second data:
50 seconds
Seiko Instruments Inc.
20 s
10 s
FFFFFF h
2-WIRE REAL-TIME CLOCK
60 s
000000 h
60 s
S-35399A03
000001 h
OFF
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