[time-nuts] Maxim DS1342

[Hal Murray]

russ.ramirez at 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.