Clear GPNVM neither JTAG nor erase. USB??

Hello everybody!!

I have a board where the JTAG interface is not available.

How ever it is possible to get acces to the USB interface.

I want to clear the GPNVM register without erase the flash,

is there any possibility to operate through the USB, and keep the contents of the flash?

Thanks in advance!

Sorry,

The chip is AT91SAM7xc512

i forgot it!!