russ.rami...@gmail.com said: > Looking across the TI and Microchip lines a bit, it strikes me as odd that > more micros supporting integrated RTCs actually use two I/Os for a 32 kHz > crystal option. Why they support an RTC is not mysterious at all, but why > not the option at to drive the 1 Hz clock directly rather than dividing 32 > kHz down to 1 Hz and using an extra I/O is odd when these I/Os are usually > configurable anyway.
A 32 KHz clock is also useful for running (well, crawling) in low power mode. That can be important when running off batteries. I suspect the reason that chips don't have an option to drive the RTC from a 1 PPS input is that there is no volume in that corner of the market. Does anybody other than a time-geek even know what PPS means? (There is a wiki page, actually 2, a disambiguation page for PPS and a another page for Pulse Per Second.) The product planners for single chip CPUs systems have a list of important customers. If you are buying a million chips a year, they will make sure that one of their next generation of chips is a good fit for your application. "Good fit" means it gets the job done and has a reasonable cost. If you are a startup with a sensible business plan that turns into a million chips a year, they will help you select one of their chips to get off the ground and discuss the good-fit/price part when you get closer to placing a large order. My million-a-year may be off by a factor of 10 (or more) either way, but I think it's the right ballpark. -- These are my opinions. I hate spam. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.