I am going to use a Dallas DS1672 Low-Voltage Serial Timekeeping Chip in a project. This chip is different from a normal RTC chip in that instead of MM/DD/YY counters and HH/MM/SS counters it contains a single 32bit seconds counter. This has the advantage of making the time keeping function in an embedded system be very inexpensive. This chip costs 1/3 to 1/2 of what other more typical RTC chips cost. In addition it takes just four byte I/O cycles to update or read the counter versus the 6->7 cycles to read MDY and HMS counters. (seven cycles for those chips that also have a day of week counter).

This chip requires an algorithm to convert to/from the 32-bit counter format to the normal display format of MM-DD-YY and HH:MM:SS. Now I do not expect that it is a particularly huge challenge to write the conversion routines, ...BUT if anybody has already done these and us willing to share please let me know.

Note: If I end up having to write them from scratch I will later post them here.

These are needed in 8051 assembler and not in C. Also it would be nice if the solution was yeap year compliant and year 2000 compliant.