Thanks Tom

I beleave the RTC 62421 Epson i'ts a good components and i'ts sure I have made mistake in some point. The question i'ts where, I have fallowed
all instructions of manual, but sometimes the clock and the data i'ts
changed.
I alwais use the serial clock Dallas
2 wire, and never problems, i'ts yhe fist time I use a parallel system
regards
Maurizio