Constant Example: Operations in arith. mod.
constant constant-name : constant-type := value
architecture arithmetic_module_arch of arithmetic_module is
architecture alu_arith_arch of alu_arith is
-- declare math opcode constants
constant ADD : std_logic_vector(1 downto 0) := "00";
constant SUB : std_logic_vector(1 downto 0) := "01";
constant MUL : std_logic_vector(1 downto 0) := "10";
constant NEG : std_logic_vector(1 downto 0) := "11";
end arithmetic_module_arch;