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--	incident_gain.vhd
--	Incident Gain Calculator
--
--	March 10, 2000
--	Ross, Daniel 355951
--
--	Given the four-bit unsigned
--  integers X and Y, we will calculate
--	gain values for each speaker,
--  A00 through A11 (4-bit unsigned, 0-15).


library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_arith.all;
use ieee.std_logic_unsigned.all;

entity incident_gain is
	generic (bitwidth : positive := 4);
	port (X, Y : in std_logic_vector (bitwidth-1 downto 0);
		 A00,A01,A10,A11 : out std_logic_vector (bitwidth-1 downto 0)
		);
end incident_gain;

architecture behavioral of incident_gain is

signal newX, newY, gain00, gain01, gain10, gain11, notX, notY: std_logic_vector(bitwidth downto 0);
signal max00, max01, max10, max11: std_logic_vector(bitwidth downto 0);

begin

not_calc: process
begin
newX(bitwidth) <= '0';
newX(bitwidth-1 downto 0) <= X(bitwidth-1 downto 0);
newY(bitwidth) <= '0';
newY(bitwidth-1 downto 0) <= Y(bitwidth-1 downto 0);

notX <= 16 - newX;
notY <= 16 - newY;
end process not_calc;

gain_00: process
begin
if newX > newY then
	max00 <= newX;
else
	max00 <= newY;
end if;
gain00 <= 16 - max00;

if notX > newY then
	max01 <= notX;
else
	max01 <= newY;
end if;
gain01 <= 16 - max01;

if newX > notY then
	max10 <= newX;
else
	max10 <= notY;
end if;
gain10 <= 16 - max10;

if notX > notY then
	max11 <= notX;
else
	max11 <= notY;
end if;
gain11 <= 16 - max11;
end process gain_00;

to_output: process
begin

A00(bitwidth-1 downto 0) <= gain00(bitwidth-1 downto 0);
A01(bitwidth-1 downto 0) <= gain01(bitwidth-1 downto 0);
A10(bitwidth-1 downto 0) <= gain10(bitwidth-1 downto 0);
A11(bitwidth-1 downto 0) <= gain11(bitwidth-1 downto 0);

end process to_output;

end behavioral;