It is always safe powering with a lower voltage. Whether it works or not is another matter. However this sort of thing should work, the only thing to watch is the voltage v maximum clock speed graph in the data sheet, but at 4v5 you are fine.
It is always safe powering with a lower voltage. Whether it works or not is another matter. However this sort of thing should work, the only thing to watch is the voltage v maximum clock speed graph in the data sheet, but at 4v5 you are fine.