of bits) of the instruction word is decoded (either by
control signals directly.
With vertical encoding, which combinations of signals and
operations are possible is dictated by the decoding logic; the
instruction field can only select one of these preprogrammed
combinations. This has the advantage that many control
signals can be generated based on only a few instruction word
bits and only valid combinations of control signals can be
generated, e.g. only one source driving a
bus at once. An
encoding within each instruction.
(1995-04-23)