[avr-libc-dev] Re: How many bits wide is __data_load_end?

[David Brown]

On 02/10/2010 15:43, Bob Paddock wrote:
> On Sat, Oct 2, 2010 at 8:24 AM, Simone Zamboni<address@hidden>  wrote:
>
> > By the way, a note for me: Bob, how much time does the XMEGA take to
> > verify all the code (roughly)? Reading all the flash data seems to take
> > a few seconds.
>
> I will have to measure the time.  I'd guess a little less than two
> seconds with my current code, at 8 MHz.
> I only run the CRC when the PORF bit (Power Applied) is set, rather
> than at all resets.
> I have to meet some regulations that require the system to be "fully
> operational in under one second".
>
> In the XMega you could switch to the 32 MHz Osc. to run the start up
> code, I don't for power reasons.

I can't comment on this case in particular (having not used an XMega 
yet), but from a power-consumption viewpoint there will be little 
difference between running for 2 seconds at 8 MHz, or running for 0.5 
seconds at 32 MHz and sleeping for 1.5 seconds - most often, running 
faster for shorter times and sleeping longer will give you lower total 
power consumption.

mvh.,

David