You are right.

E.g. on one project also the DS1994 was "most suitable" for me.
Since it consume only one I/O-Pin and need no additional hardware except a single pull up resistor of 2.2kOhms.

In general the term "suitable" was only meaningful in respect to your requirements.

E.g. any parallel RTC was not suitable for me, since it consume to many I/Os.


Furthermore I made very bad experience with 4-bit parallel RTC, since its to easy to alter the time information accidentally by hazards during power up or power down.

But the DS1994 has excellent immunity against such malfunction, because a long serial sequence must be matched until it accept any new data.

I try now to collect some experience about the accuracy of the DS1994.


Peter