Interface RTC With 8051

A Real Time Clock is like a watch – it runs on a battery and keeps time even when there is a power outage.

• DS1307 is an I2c based serial real time clock (RTC).
• RTC keep track of seconds, minutes, hours, date of month, month, day of month and year with leap year compensation which is valid upto year 2100.
• The clock can be programmed to operate either in 12-hour or 24-hour format.
• DS1307 requires very less number of components to operate.
• RTC DS1307 operate in frequency of crystal oscillator 32.768kHz.
• DS1307 uses I2C Protocol.
• RTC act as a slave device and I2C Master can read/write register of RTC.
• To communicate with the slave device, master need the slave address of device connected on bus.
• DS1307 has fixed slave address.
  • Slave Address
  • 7-Bit format: 0b1101000 = 0x68
  • Slave address for I2C Write: 0b11010000 = 0xD0
  • Slave address for I2C Read: 0b11010001 = 0xD1.

Application

• Digital Clock.

Hardware Required

Pinout

• SCL and SDA to port pins.
• Gnd: Gnd.

Circuit