ds1307 problem with 8051

[hassan ali]

hi, i have build my own program (interfacing 8051 with ds1307) but i want to do this steps:
lets say that the day now is 21/5/2011 so i want from ds1307 to get the micro controller a pulse output from rtc after 3 days
i.e: at day 24 i want to get pulse from rtc how can i do it using square output pin in rtc, please answer me .

 

[erio]

you can set the SQWE bit in control register of 1307 when the date is 24. and disable it again.
but it is easier to implement this on 8051 side (i.e compare the day variable with preset and set port bit to 1 if equal, delay, and set to 0 again)

good luck

 

[hassan ali]

I tried to do it but i can't , because i want to update the value 24 each 3 days and send a clock pulse again, but i can't do it