The recommended crystal oscillator frequency for the DS1306EN is 32.768 kHz. This frequency is used to drive the internal oscillator and provides the clock signal for the real-time clock (RTC) function.
The initial time and date on the DS1306EN can be set by writing the desired values to the corresponding registers using the I2C interface. The registers are organized as follows: seconds (register 0x00), minutes (register 0x01), hours (register 0x02), day of the week (register 0x03), day of the month (register 0x04), month (register 0x05), and year (register 0x06).
The SQW (Square Wave) pin on the DS1306EN is an output pin that generates a square wave signal at a frequency of 1 Hz, 4.096 kHz, 8.192 kHz, or 32.768 kHz, depending on the value written to the SQW frequency selection bits (register 0x07, bits 4-6). This pin can be used to drive an external clock or timer circuit.
The DS1306EN automatically handles leap years by incrementing the date to February 29 in leap years. Leap years are defined as years that are divisible by 4, except for years that are divisible by 100 but not by 400.
The maximum operating temperature range for the DS1306EN is -40°C to +85°C. However, the device can be stored at temperatures between -55°C and +125°C.
DS1306EN datasheet
by Maxim Integrated Products
