¿Cómo mostrar los números en la pantalla VGA en VHDL?

Tengo un código para mostrar el bloque en la pantalla VGA pero quiero mostrar los números en él. Tengo una pequeña idea de cómo diseñarlo, pero programáticamente, estoy teniendo dificultades. Puedo definirlo como una constante en términos de número binario como este:              constante uno :: = (0 = > ”0000001110000000”,                        1 = > ”0000001110000000”,                        2 = > ”0000001110000000”,                        3 = > ”0000001110000000”,                        4 = > ”0000001110000000”,                        5 = > ”0000001110000000”,                        6 = > ”0000001110000000”,                        7 = > ”0000001110000000”,                        8 = > ”0000001110000000”,                        9 = > ”0000001110000000”,                      10 = > ”0000001110000000”,                      11 = > ”0000001110000000”,                      12 = > ”0000001110000000”,                      13 = > ”0000001110000000”,                      14 = > ”0000001110000000”,                      15 = > ”0000001110000000”);

   library IEEE;
   use IEEE.STD_LOGIC_1164.ALL;
   use IEEE.STD_LOGIC_ARITH.ALL;
   use IEEE.STD_LOGIC_UNSIGNED.ALL;

  --  Uncomment the following lines to use the declarations that are
  --  provided for instantiating Xilinx primitive components.
  --library UNISIM;
  --use UNISIM.VComponents.all;

  entity TheirVGA is
  port(mclk, btn, reset: in std_logic;
    vs, hs: out std_logic;
    red, grn, blu, led: out std_logic);
  attribute syn_noclockbuf : boolean;
  attribute syn_noclockbuf of btn : signal is true;
      end TheirVGA;


  architecture Behavioral of TheirVGA is

  signal clkPix: std_logic;
  signal cntHorz, cntVert: std_logic_vector(9 downto 0);
  signal sncHorz, clkLine, blkHorz: std_logic;
  signal sncVert, blkVert, blkDisp, clkColor:   std_logic;
  signal cntImg: std_logic_vector(6 downto 0);
  signal cntColor: std_logic_vector(2 downto 0);
  signal upper, left, lower, right: std_logic_vector(11 downto 0);


  begin
     ---------------------------------------------------------------
            VGA Controller Test
------------------------------------------------------------------------

-- Divide the D2XL oscillator down to form the pixel clock
-- that is the basis for all of the other timing.
process (mclk)
    begin
        if mclk = '1' and mclk'Event then
            clkPix <= not clkPix;
        end if;
    end process;

-- Generate the horizontal timing.
process (clkPix)
    begin

        if clkPix = '1' and clkPix'Event then
            if cntHorz = "0001011101" then
                cntHorz <= cntHorz + 1;
                sncHorz <= '1';
            elsif cntHorz = "0010001100" then
                cntHorz <= cntHorz + 1;
                blkHorz <= '0';
            elsif cntHorz = "1100001100" then
                cntHorz <= cntHorz + 1;
                blkHorz <= '1';
            elsif cntHorz = "1100011010" then
                cntHorz <= "0000000000";
                clkLine <= '1';
                sncHorz <= '0';
            else
                cntHorz <= cntHorz + 1;
                clkLine <= '0';
            end if;
        end if;
    end process;

-- Generate the vertical timing.
process (clkLine)
    begin

        if clkLine = '1' and clkLine'Event then
            if cntVert = "0000000001" then
                cntVert <= cntVert + 1;
                sncVert <= '1';
            elsif cntVert = "0000011010" then
                cntVert <= cntVert + 1;
                blkVert <= '0';
            elsif cntVert = "0111111010" then
                cntVert <= cntVert + 1;
                blkVert <= '1';
            elsif cntVert = "1000001100" then
                cntVert <= "0000000000";
                sncVert <= '0';
                      if(reset = '1') then
                            left <= X"12C";
                            right <= X"1F4";
                            lower <= X"1C2";
                            upper <= X"0FA";
                        elsif(btn = '1') then
                            left <= left - 2;
                            right <= right - 2;
                            lower <= lower - 1;
                            upper <= upper -1;
                        end if;
            else
                cntVert <= cntVert + 1;
            end if;
        end if;
    end process;

-- Divide the active portion of a scan line into 8 regions.
-- This counts up to 79 and then resets. Each time it
-- resets, it generates a pulse on clkColor.
process (clkPix, blkDisp)
    begin
        if clkPix = '1' and clkPix'Event then
            if blkDisp = '1' then
                cntImg <= "0000000";
            else
                if cntImg = "1001111" then
                    cntImg <= "0000000";
                    clkColor <= '1';
                else
                    cntImg <= cntImg + 1;
                    clkColor <= '0';
                end if;
            end if;
        end if;
    end process;

-- Increment the output color for each scan line region.
    --process (clkPix, clkColor, blkDisp)
  --  begin
  --      if clkPix = '1' and clkPix'Event then
   --         if blkDisp = '1' then
     --           cntColor <= "111";
       --     else
         --       if clkColor = '1' then
      --              cntColor <= cntColor + 1;
      --          end if;
      --      end if;
      --  end if;
    --end process;

 led <= btn;
blkDisp <= blkVert or blkHorz;
cntColor <= "110" when cntHorz < right and cntHorz > left and cntVert < lower and cntVert > upper else "100"; -- and  else "111";
vs  <= sncVert;
hs  <= sncHorz;
blu <= cntColor(0) and (not blkDisp);
grn <= cntColor(1) and (not blkDisp);
red <= cntColor(2) and (not blkDisp);

end Behavioral;