tribuf - infer tri-state buffers

yosys> help tribuf

tribuf [options] [selection]

This pass transforms $mux cells with 'z' inputs to tristate buffers.

-merge

merge multiple tri-state buffers driving the same net
into a single buffer.

-logic

convert tri-state buffers that do not drive output ports
to non-tristate logic. this option implies -merge.

-formal

convert all tri-state buffers to non-tristate logic and
add a formal assertion that no two buffers are driving the
same net simultaneously. this option implies -merge.