DS1306

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32 kHz (32.768 kHz Clock Output) - The 32 kHz pin provides a 32.768 kHz output. This signal is

always present.

X1, X2 - Connections for a standard 32.768 kHz quartz crystal. The internal oscillator is designed for

operation with a crystal having a specified load capacitance of 6 pF. For more information on crystal

selection and crystal layout considerations, please consult Application Note 58, “Crystal Considerations

with Dallas Real Time Clocks.” The DS1306 can also be driven by an external 32.768 kHz oscillator. In

this configuration, the X1 pin is connected to the external oscillator signal and the X2 pin is floated.

RTC AND RAM ADDRESS MAP

The address map for the RTC and RAM registers of the DS1306 is shown in Figure 2. Data is written to

the RTC by writing to address locations 80h to 9Fh and is written to the RAM by writing to address

locations A0h to FFh. RTC data is read by reading address locations 00h to 1Fh and RAM data is read by

reading address locations 20h to 7Fh.

ADDRESS MAP Figure 2

00H

1FH

CLOCK/CALENDAR

READ ADDRESSES ONLY

20H

7FH

96-BYTES USER RAM

READ ADDRESSES ONLY

80H

9FH

CLOCK/CALENDAR

WRITE ADDRESSES ONLY

A0H

FFH

96-BYTES USER RAM

WRITE ADDRESSES ONLY