Re: [Mspgcc-users] [RFC] Precision DCO for F161x

[Chris L. <cli...@gm...>]

Garst R. Reese wrote:
> Steve has pretty much convinced me of the power savings advantages of 
> DCO, but I worried about providing a reliable and sufficiently accurate 
> clock for a 115200 serial line. For this purpose,  I was using a 
> 3.684MHz crystal. Although Fredic reports reports success with DCO and  
> the FLL algorithm (not applicable to the F161x parts), I am still 
> concerned about part variation.

we adjust our products with an external clock when they are in the 
testbed. the devices need also other values calibrated, so it's cheap to 
adjust the clock too.

[...]
> In my application, I am also using a DS1390 RTC with battery backup, 
> which outputs a 32768Hz  signal connected to TB0.

you could also feed it to XIN, then you can use it as ACLK for 
peripherals that are accurate enough with the 30+something microseconds 
reslolution. (e.g. keep the timer_A/B running wile the CPU is in LPMx 
mode, using the slowest possible clock saves energy)
and in addition, you save a pin ;-)

chris