View Full Version : In the interest of battery power conservation

01-12-2008, 01:24 AM
Our Prop. Chip application needs crystal operation (for timing purposes) but requires the lowest power consumption possible.
For a given operation up to two cogs may be running at the same time.
Using the 5 MHz crystal, can we specify object (all Methods) operation on 1 MHz editing the following CON statement from:

· _xinfreq=5_000_000
· _clkmode=xtal1+pll1x


· _xinfreq=25_000_000
· _clkmode=xtal1+pll1x

In calculating device currect draw, (500ua*1.25)*2=1.25ma for 5 MHz operation, it would instead be (500ua*0.25)*2=250ua.


01-12-2008, 01:47 AM
No, not at all http://forums.parallax.com/images/smilies/smile.gif
The crystal is the crystal... There is no further intelligence with the _xinfreq at all. It's just a number to inform the software; if wrong it will confuse everybody.
Just take a 1MHz crystal!

And don't use pll1x! Leave the PLL out for heavens sake!

01-12-2008, 01:53 AM
tnx deSilva.