Electronic – What are similarities between RTC DS1374 and RTC DS1307


I mostly work in software and not good in reading Hardware data sheets.

I need help in understanding the similarities between RTC DS1374 and RTC DS1307,From below link I could make out that both share the same address on I2C bus and have same set of registers but still few doubts would like to ask.


1) Do both DS1307 and DS1374 have exactly same copy of register set?

2). Do both stores times as year-month-day-hours-minutes-seconds?

3). Do both have have their registers mapped to NVRAM of equal size?

How much DS1307 code can be reused on DS1374?

Any comment would be useful.


Best Answer

These two parts are dissimilar in many many ways.

The block diagrams alone tell much of the story.

DS1374 enter image description here

DS1307 enter image description here

Similarities are limited to the basic functionality of the I/O pins:

  • X1
  • X2
  • VCC
  • GND
  • SCL
  • SDA
  • SQW

Internally the parts diverge greatly.

The '1374 simply uses a 32-bit counter to keep track of the passage of seconds. The software that reads the counter has to translate the count into the normal clock date/time components. On the other hand the '1307 keeps track of the individual date/time components as BCD (binary coded decimal) values in individual registers.

Beyond the basic RTC features the '1374 offers a 24-bit counter that can serve as a WDT (watch dog timer) with an interrupt output and a reset output.

On the other hand the '1307 offers 56 bytes of battery backed up RAM for user data.

In a simple nutshell - you cannot use common software to support these two parts. The register maps are completely different.

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