The AD5335 have a parallel interface. CS selects the device and data is loaded into the input registers on the rising edge of WR.
On the AD5335 an asynchronous CLR input is also provided. This resets the contents of the input register and the DAC register to all zeros. These devices also incorporate a power-on-reset circuit that ensures that the DAC output powers on to 0V and remains there until valid data is written to the device.