A two-species asymmetric exclusion process is considered with general
transition rates subject only to the constraint of charge conservation
. Conditions for the existence of a stationary product measure are fou
nd in both the cases of odd-even parallel dynamics and continuous-time
dynamics. The results are then applied to a one-dimensional restricte
d solid-on-solid model, considered as a model of driven interfacial gr
owth, showing a nontrivial dependence of the stationary measure on the
external driving field. The dependence of the growth velocity on the
slope of the interface is given and interface shapes in finite volume
with opposite boundary conditions are investigated numerically.