--------------------------------------------------
-- EE 552 Project, Automatic Volume Control
--
-- Mark Mielke, Mar 14, 2000
-- Revisions:
-- Kreshka Niehaus, March 24, 2000
-- Amplification Calculation Block
-- Rev 3, Adding the display 
--
-- inputs are clk and:
--		** MS 8-bits from Integrator (Noise Out Block)
--	This will indicate the level of the ambient noise.
--		** Two 8-bit vectors from the Max_Min Block
--	One vector represents the Max Volume, the other vector
--	represents the minimum volume.
--
-- outputs are: 
-- 		** An 8-bit vector to the Amp Display Block
--  This will indicate the level of amplification performed.
--		** An 8-bit vector to the Gain Controller
--  These may be the same output? -> assume so for now.
--------------------------------------------------

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

entity amp_calc is
	port(
		clk: in std_logic;
		noise_in: in std_logic_vector(7 downto 0);
		maxvol, minvol: in std_logic_vector(7 downto 0);
		ampcalc_out: buffer std_logic_vector(7 downto 0);
		count_out: out std_logic_vector(13 downto 0)
	);
end amp_calc;


architecture mixed of amp_calc is

--from ssdisplay.vhd
component ssdisplay
	port(
		level : in std_logic_vector(3 downto 0);
		seg1: out std_logic_vector(6 downto 0)
		);
end component;

--split 8 bit binary number into 4s to convert to hex
signal upper_count_in,lower_count_in: std_logic_vector(3 downto 0);
signal upper_count_out,lower_count_out: std_logic_vector(6 downto 0);
signal count_in: std_logic_vector(7 downto 0);

begin

ac: process (clk)
begin

if rising_edge(clk) then

  if noise_in <= minvol then
	ampcalc_out <= minvol;
  elsif noise_in >= maxvol then
	ampcalc_out <= maxvol;
  else
	ampcalc_out <= noise_in;
  end if;
  count_in<=ampcalc_out;
end if;

end process ac;

--split count_in into 4 bit segments
upper_count_in <= count_in(7 downto 4);
lower_count_in <= count_in(3 downto 0);


count_upper: ssdisplay port map(
	level => upper_count_in,
	seg1 => upper_count_out);

count_lower: ssdisplay port map(
	level => lower_count_in,
	seg1 => lower_count_out);

-- put count_out parts together with concatenation
count_out <= upper_count_out & lower_count_out;

end mixed;