Q:

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.
http://spellfoundry.com/arduino/ds1374-rtc-arduino-library-2/
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.
Thanks.

A:

These two parts are dissimilar in many many ways.
The block diagrams alone tell much of the story.
DS1374

DS1307

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

X1 
X2
VCC
VBACKUP
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. 

