Hi Mak,

The 8583 handles year differently than other RTCs I've seen. Your two bits for year are simply to handle the four year cycle for leap years, so month is incremented properly. "Year" should probably be called "leap year." As far as the actual year is concerned, that's up to you to handle.

Thus when you set the year, you probably will set aside a ram location to store it, and load the 2-bit year according to the year. Then you need to notice when the year changes, and increment the year manually. For year 2000, "leap year" would be 0; for year 2002, "leap year" would be 2, etc.

For our projects we chose the PCF8563, which has two digits for year, and a century flag.

Dennis