How to ensure that a pin never floats
Assumption: Based on the wording of the question, presumably certain input pins must not be floating to a "high" condition when the AD7541A is powered on. 

The conventional method of preventing a pin from floating, i.e. ensuring that it is held low until some logic state is imposed upon it by an external device, is to use a pull-down resistor on the pin in question. 

A pull-down resistor is simply a resistor of high value, connected between the pin in question, and the circuit ground. The value of the resistor should be high enough than the external device that needs to assert a value upon the pin at some time, is not unduly loaded, or in the case of analog input pins, unduly distorted in overcoming the resistor's effect.

Common pull-down values are 10 kOhms or 100 kOhms. For analog inputs that must be held low until externally asserted, sometimes 1 MegaOhm resistors are used. The selection of resistor value must be such that it is significantly higher than the output impedance of the pin or device that will be asserting a value on the pulled-down pin during normal operation. At the same time, too high a resistance value will leave the pin susceptible to stray noise pulling the pin high on occasion.

The reason for using very high values for analog inputs, when a pull-down is used at all, is that if the source impedance the analog input is to read is of comparable magnitude to the pull-down resistance, the combination will act as a voltage divider, lowering the voltage seen by the analog input during operation.