Why are you connecting two MCUs ?

and yes if it is necassary then it must be done as you told, but if it is not necassary then there are plenty of options just like IIC,

or you can also create your own like two wire interface ,

1, for Clock P1.0
2, for Data P1.1

well if you want to impliment the Protocol, the Slave MCu must be waiting for the Trasition on the clock (P1.0), and with each transition on clock it must read data on Data Pin (P1.1),

and you can also set your own codings for the Communications,

Hoping that you would get the idea,

if you havent gotten the idea then Reply,

DareDevil