Can DAC SPI pins be left floating for a while before the micro is configured by KenK
Ideally, the SPI pins should not be left floating when the DAC is powered up. Noise in the system could cause glitches which could be interpreted by the DAC as part of a write operation and may confuse the interface. If the micro powers up after the DAC or it's I/O port is three-state before it's configured then it is best to use pull down resistors on the SPI and other digital pins.