-- Pseudo-random number decoder
--
-- Signals:
--   din: 5 bits pseudo-random number input
--   dout: 4 bits binary number output

library ieee;
use ieee.std_logic_1164.all;

-------------------------------------------------------
-- psedo-counter decoder
-------------------------------------------------------
entity pcount_decoder is
  port (din  : in std_logic_vector (4 downto 0);
        dout : out std_logic_vector (3 downto 0)
       );
end;

architecture arch of pcount_decoder is

begin

  dout <= "0000" after 5 ns when (din = "01111") else
          "0001" after 5 ns when (din = "00111") else
          "0001" after 5 ns when (din = "10111") else
          "0010" after 5 ns when (din = "00011") else
          "0010" after 5 ns when (din = "10011") else
          "0011" after 5 ns when (din = "00001") else
          "0011" after 5 ns when (din = "10001") else
          "0100" after 5 ns when (din = "01000") else
          "0100" after 5 ns when (din = "11000") else
          "0101" after 5 ns when (din = "00100") else
          "0101" after 5 ns when (din = "10100") else
          "0110" after 5 ns when (din = "00010") else
          "0110" after 5 ns when (din = "10010") else
          "0111" after 5 ns when (din = "01001") else
          "0111" after 5 ns when (din = "11001") else
          "1000" after 5 ns when (din = "01100") else
          "1000" after 5 ns when (din = "11100") else
          "1001" after 5 ns when (din = "00110") else
          "1001" after 5 ns when (din = "10110") else
          "1010" after 5 ns when (din = "01011") else
          "1010" after 5 ns when (din = "11011") else
          "1011" after 5 ns when (din = "00101") else
          "1011" after 5 ns when (din = "10101") else
          "1100" after 5 ns when (din = "01010") else
          "1100" after 5 ns when (din = "11010") else
          "1101" after 5 ns when (din = "01101") else
          "1101" after 5 ns when (din = "11101") else
          "1110" after 5 ns when (din = "01110") else
          "1110" after 5 ns when (din = "11110") else
          "1111" after 5 ns when (din = "11111") else
          "----" after 5 ns;

end arch;