As long as these chips you have are supplied with an enable pin of some kind, there is no reason you can't have them all share the same data pin. But you'll have to come up with other processor pins to exercise these enable pins. Most enables are low-true, meaning that the chip is only usable while the ENable (AKA CS) pin is low. So if you have two slave chips, you'll have to use two of your I/O pins to select which you are using at the time. Pull the EN pin low of the chip you want to access and be DAMN sure the other EN pin is high.
BTW, which chips do you have?
HTH
kenjj