horizontal encoding

1 definition found

horizontal encoding - Free On-line Dictionary of Computing (26 May 2007) :

  horizontal encoding
  
     <processor> An instruction set where each field (a bit or
     group of bits) in an instruction word controls some
     functional unit or gate directly, as opposed to vertical encoding
      where instruction fields are decoded (by
     hard-wired logic or microcode) to produce the control
     signals.  Horizontal encoding allows all possible combinations
     of control signals (and therefore operations) to be expressed
     as instructions whereas vertical encoding uses a shorter
     instruction word but can only encode those combinations of
     operations built into the decoding logic.
  
     An instruction set may use a mixture of horizontal and
     vertical encoding within each instruction.  Because an
     architecture using horizontal encoding typically requires more
     instruction word bits it is sometimes known as a very long instruction word
      (VLIW) architecture.
  
     (1995-04-23)