RV5C387A

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8. Typical Software-based Operations

8.1 Initialization at Power-on

Start

XSTP=1?

Power-on

NO

NO

YES

YES

Warning of Backup Battery

Run-down

Set Oscillation Adjustment Register

and Control Registers 1 and 2, etc.

VDET=0?

*

1

*

2

*

4

*

3

8.2 Writing of Time and Calendar Data

Stop condition

Start condition

Write to clock and

calendar counters

*

2

*

1

*

3

access should be done after the lapse of this time span or more.

presence of any excessive chattering in power supply in such events as installing backup battery. Should there be any possibility of this failure occurring,

it is recommended to initialize the RV5C387A regardless of the current XSTP bit setting. For further details, see “3. Oscillation Halt Sensing and Supply

Voltage Monitoring”.

until all times from second to year have been written to prevent error in

writing time. (Detailed in “1.2-6 Data transmission under special

condition”.

second digits.

complete within 0.5sec. (Detailed in “1.2-6 Data transmission under

special condition”.

The RV5C387A may also be initialized not at power-on but in the process

of writing time and calendar data.