During power-up and configuration modes, the sleep signal must be low. When the sleep signal is asserted, the device immediately enters sleep mode. Upon entering sleep mode, the functionality of the device such as GCLK networks and I/O buffers are dynamically powered down—to minimize dynamic power dissipation. All configuration data is retained when the device is in the sleep mode.
не понятно, это ногу слип в ноль нужно опустить до подачи питания?