How to genrate interrupts every 0.1s or 0.01s using DS12887?

[DrWhoF]

I send data from 87C52+DS12887 (6818 RTC) via serial port to a PC.
Data string contains date and time as follows.
DD-MM-YYYY,HH:MM:SS.
I want to send data every 0.1s or 0.01seconds.How to genrate interrupts every 0.1s or 0.01s using DS12887?
DD-MM-YYYY, HH:MM:SS.XX

 

[IanP]

Re: 6818 RTC and 0.01s

The DS12887 can not directly generate 0.01 or 0.1s interrupt ..
The closest you can get is ≈977µs (Periodic Interrupt Rate RS0=0, RS1=1, RS2=1 and RS3=0) ..
If you count this interrupt for 10 times you will end up with 0.00977s, or if the count is 103 the result is 0.1006s .. is it good enough?

Regards,
IanP

 

[DrWhoF]

Re: 6818 RTC and 0.01s

I have problems with synchronization of 0.1s generated by 0.1006s interrupts and 1s clock. How to synchronize them?

 

[IanP]

Re: 6818 RTC and 0.01s

I guess you have a counter that counts 977µs interrupts, so the obvious thing to do is to zero this counter on 1s interrupt ..

Regards,
IanP