I have a question that the power section in the Atmega328p datasheet does not seem to cover. I was planning on running my system at 1MHZ with a 2.8V VCC for a good trade off of power vs performance. As it turns out 1MHz crystals and resonators do not seem to exist, Digikey has none.
If I run a divide by 8 (set with the fuse bits) attached to an 8MHz crystal, from a power standpoint will that be the same as a 1MHz clock? Obviously there will be some small additional losses from the 8MHz in-front of the clock divider but since the CPU and assorted other clock domains are slower, I'm assuming it will have a power draw close to 1MHz.
Is this correct?
EDIT I can not use the internal oscillator as I require accurate timing across a large temperature range. Also I have reviewed the datasheet and the question is asking if I feed a 8MHz clock and scale it by 8 to 1MHz is the approximately the same power use as a raw 1MHz clock.