NOR Powered on!!!

Hi all!
I accidentally have switched between NOR-NAND while the board was enabled!
Do anybody know what could go wrong with this?
Is it possible to loose same data or be unable to boot?

Hi Xristos ! i tried it once and nothing happened to the board, it remained
totally normal.

Regards.

Thank you mustapha
I was not so carefull so I did it more than once. I had a software problem
and I wanted to be sure it is not something more!

Don't worry about it, i did it more than once too ;)

Regards