package ap_a_01 is

  -- code from book

  attribute enum_encoding : string;

  type state is (idle, preamble, data, crc, ok, error);
  attribute enum_encoding of state : type is "000 001 010 011 100 111";

  type sample is range -64 to 63;
  subtype table_index is natural range 0 to 1023;

  type coeffs is array (3 downto 0) of integer;

  type channel_states is array (0 to 7) of state;  -- state is an enumeration type

  subtype word is bit_vector(31 downto 0);
  type reg_file is array (0 to 15) of word;


  type color is (red, green, blue);
  type plane_status is array (color) of boolean;  -- non-integer index type

  type matrix is array (1 to 3, 1 to 3) of real;  -- two-D, and floating-point elements

  type reg_file_set is array (0 to 3) of reg_file;  -- elements are vectors of non-bits

  -- end code from book

end package ap_a_01;