timer

[Neo]

I hope this is related but what exactly is the use of the RTC ? does anyone have any good documents related to this?

[Neo]

In Tannenbaum's book referring to the clock function to maintain the time of day. I just wanted to know if this is still relevant or necessary. Couldn't we just read the time from the RTC if we wanted it? do we have to "maintain the time of day" ourselves?

[df]

you can sync up with the cmos whenever the clock is called to get an accurate map, but if you have something that sits in a loop and prints a clock/date time... thats a lot of calls to the (slow) cmos...

most OS change the freq of the irq timer... which isnt very accurate anyway.... you will get clock drift if you maintain it in software...

rtc/watchdog/cmos etc...