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I am looking for the lwest power Cortex M-?
I don't want to spend years searching the internet for a low-power ARM Cortex controller.
Does anybody know of one?
(And yes, it is Keil related since I'll be using Keil to program it)
Thanks,
--Cpt. Vince Foster 2nd Cannon Place Fort Marcy Park, VA
Battery Size is TBD dependent upon the electronics, but so far the calculated budget allows for a 32 hours on a 2800mA/H LiIon: in what I think is 'worst case'. But of course simulation versus the real thing can be wrong.
Per is right about the external peripherals' power usage. Those have been addressed and mitigated.
A purpose behind knowing a low-power Cortex is an evaluation of the actual MIPS truly needed to accomplish the same goal as a 'fast' 8051.
Like cars, you'll find that they size the gas tank to ensure at least 300 miles between refueling to prevent the owner from thinking it is a gas hog, or get annoyed by constantly going to the gas station.
The same will happen on this project. I don't want the customer spending 'too much time' charging the unit.
Although I said before, that 24 hour mark is for the heavy user who uses it for 8+ hours at a time, while the typical user would use it for about an hour at a time.
Another aspect of the project is to convert the discrete CPUs (uCs) into an FPGA fabric. Thus the code-monkey-book shall be followed to make that "C" to VHDL transition... then I'll clock it down to reach for optimal battery life while still maintaining performance.
MCB1000 ?
No such thing listed at http://www.keil.com/boards/
"2800mA/H"
I expect you meant 2800mAh @ 3.6V since you need voltage*current*time to get energy, and that you are talking about a one-cell battery. Say 8W usable after losses from a DC/DC.
Counting 12 hours operation and a 90% power reduction for the idle hours, that would give about 0.6W when active and 0.06W in idle. Assuming 50% for the cores to process instructions, and 50% for internal modules (DMA, UART etc) and external logic, you would have 0.3W for instruction processing.
If the claim of 0.09mW/MHz is true for the 0.13G process, your 0.3W would then be enough for 300/0.09 [MHz] = 3.3 GHz or 33 processors running at 100MHz.
Processors using the 0.18G process would give you 300/0.19 [MHz] = 1.6 GHz.
I really must have computed something wrong, but the figures sounds quite large ;)
Just a footnote, but I normally add a *0.5 as safety margin when doing initial calculations, to cover ageing of batteries, unknown late-stage requirement changes etc and still have a bit of extra engineering margin. Better to be able to reduce the battery size after measuring on prototypes than to have to figure out how to fit a larger battery pack in a too small box after the tools for making the box have already been produced.
Absolutely!!!
Follows the general "make it work first; optimise later" approach.
Please check Cypress PSCO5 (available only on january)
With some effort you can increase the power of these ones:
www.ehow.com/how_4791464_tone-flabby-arms.html
Really - at last?!
See: www.8052.com/.../165761