thank u it was useful !Depending on the part we are talking about it may be as simple as the external wiring. There will probably be no power saving from using half-duplex.
Here is a part that can be used either way: full duplex or half duplex.
http://www.ti.com/lit/ds/symlink/sn65hvd1476.pdf
by Jake Hertz
by Jake Hertz
by Jake Hertz