RTC INTERFACING to 8051
RTC INTERFACING 9.1 INTRODUCTION The real time clock is most widely device that provides accurate time and date for many applications. RTC chip has the capability of providing time components of hour, minute and second, in addition to date/calendar components of year, month, and day. The RTC chip uses an internal battery, which keeps the time and date even when power is off. Although some 8051 microcontrollers come with RTC embedded into the chip, we have to interface vast majority of them external to the 8051 chip. One of most widely used RTC chip is DS1307 from Dallas Semiconductor/Maxim Corp. This RTC chip has specific features of Two-wire Serial Interface. The DS1307 Serial Real-Time Clock is a low-power; full binary-coded decimal (BCD) clock/calendar plus 56 bytes of NV SRAM. Address and data are transferred serially via a 2-wire, bi-directional bus. The clock/calendar provides seconds, minutes, hours, day, date, month, and year information. The end of the month date is automat