At 04:49 PM 6/26/2004 +0200, Kyrre Aalerud wrote:

>My bootloader is coming along nicely :)
>I have most of the functionality in place now.
>
>Specs are now:
>- uses 106 words
>- saves interrupt states and goes to a new interrupt-vector.
>- receives data in 32 word blocks (32x2 bytes) wich are programmed and acked
>for next block.
>- does not reprogram first 256 words or memory as this block can be
>protected by the internal memory fuse.

What happens if I pull the cable in mid-load?
Will the system recover, or become a "brick" that can only be recovered with a chip programmer?

You could use LRC, which is simply an addition of all the bytes in the packet, throwing away the overflow, or "add, triple, add" which is used in UPC/EAN barcodes.
Both are very easy to implement, and for short packets, pretty reliable.

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