library IEEE;
use IEEE.std_logic_1164.all;
use IEEE.std_logic_arith.all;

entity Vprior2 is
    port (
        R: in STD_LOGIC_VECTOR (0 to 7);
        A, B: out STD_LOGIC_VECTOR (2 downto 0);
        AVALID, BVALID: buffer STD_LOGIC
    );
end Vprior2;

architecture Vprior2_arch of Vprior2 is
function CONV_STD_LOGIC_VECTOR(ARG: INTEGER; SIZE: INTEGER)
    return STD_LOGIC_VECTOR is   
  variable result: STD_LOGIC_VECTOR (SIZE-1 downto 0);
  variable temp: integer;
begin
  temp := ARG;
  for i in 0 to SIZE-1 loop
    if (temp mod 2) = 1 then result(i) := '1';
    else result(i) := '0';
    end if;
    temp := temp / 2;
  end loop;
  return result;
end;
begin
  process(R, AVALID, BVALID)
  begin
    AVALID <= '0'; BVALID <= '0'; A <= "000"; B <= "000";
    for i in 0 to 7 loop
      if R(i) = '1' and AVALID = '0' then
        A <= CONV_STD_LOGIC_VECTOR(i,3); AVALID <= '1';
      elsif R(i) = '1' and BVALID = '0' then
        B <= CONV_STD_LOGIC_VECTOR(i,3); BVALID <= '1';
      end if;
    end loop;
  end process;
end Vprior2_arch;