Thanks!
The LVD is disable.
The reset is alwais high.
I have test my board with Vcc=2.8V and I have see XTAL (PTB1) alwais high. If I tap the pin of microcontroller with a finger the oscillator wakeup and it run then I suppose is the oscillator.
My supposition is wrong?
Vcc is not to low, is 2.8V.
Thanks again!