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

[Bob Paddock]

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.

Real Soon Now I want to switch to the XMega hardware CRC calculator,
but I have to write some code of the PC
that precalculates the CRC Magic Number to put into the last three
bytes of the application space.
That way a good CRC will always have a constant value.
 Be aware that the XMega CRC Range calculation does not work in
revision prior to J; that don't seem to exist yet.

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