I first got into the MSP430 trying to keep power consumption down when
running from one lithium coin cell. Since then, Microchip has introduced
PICs that do really well in that application. But what I can suggest is
to look at the power consumption at the voltage you are actually running
the chip. Choose your architecture based upon that. PIC may be better
than MSP430, or it may be the other way around. Microchip and TI are not
sleeping (pun) when it comes to power consumption, but you need to look
at recent offerings because Microchip was playing catchup for a while.

Best regards,

Bob


On Sat, Aug 25, 2012, at 02:51 PM, Jim Franklin wrote:
> We run our RTC chip at 32KHz with a 0.1F supercap and that runs for about
> 3
> days (all we need in terms of offline time).
>=20
> Our idea was to have a sleeping PIC, and the WDT wakes it up every few
> minutes to keep the time ticks going - we need relative time as opposed
> to
> actual time.=20
>=20
> Unfortunately in our application, we cannot use batteries so I have
> experimented with keeping a PIC s/w RTC running on a supercap, but the
> best
> I could manage with 1F was about 12Hours - even in sleep the PIC takes a
> hearty current (17uA). For reference the same circuit on a battery would
> last about 468 years :)

--=20
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