1. The CS pin can be used to select the AD7732 as one of several circuits connected to the host serial interface. When CS is high, the AD7732 ignores the SCLK and DIN signals and the DOUT pin goes to the high impedance state. When the CS signal is not used, connect the CS pin to DGND. Отсюда CS на ноль.
2. The RESET pin can be used to reset the AD7732. When not used, connect this pin to DVDD. Отсюда RESET на +5В.