list_ch08_04_key2ascii.vhd

来自「VHDL FFT SOURCECODE great one」· VHDL 代码 · 共 72 行

-- Listing 8.4
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
entity key2ascii is
   port (
      key_code: in std_logic_vector(7 downto 0);
      ascii_code: out std_logic_vector(7 downto 0)
   );
end key2ascii;

architecture arch of key2ascii is
begin
   with key_code select
      ascii_code <=
         "00110000" when "01000101",  -- 0
         "00110001" when "00010110",  -- 1
         "00110010" when "00011110",  -- 2
         "00110011" when "00100110",  -- 3
         "00110100" when "00100101",  -- 4
         "00110101" when "00101110",  -- 5
         "00110110" when "00110110",  -- 6
         "00110111" when "00111101",  -- 7
         "00111000" when "00111110",  -- 8
         "00111001" when "01000110",  -- 9

         "01000001" when "00011100",  -- A
         "01000010" when "00110010",  -- B
         "01000011" when "00100001",  -- C
         "01000100" when "00100011",  -- D
         "01000101" when "00100100",  -- E
         "01000110" when "00101011",  -- F
         "01000111" when "00110100",  -- G
         "01001000" when "00110011",  -- H
         "01001001" when "01000011",  -- I
         "01001010" when "00111011",  -- J
         "01001011" when "01000010",  -- K
         "01001100" when "01001011",  -- L
         "01001101" when "00111010",  -- M
         "01001110" when "00110001",  -- N
         "01001111" when "01000100",  -- O
         "01010000" when "01001101",  -- P
         "01010001" when "00010101",  -- Q
         "01010010" when "00101101",  -- R
         "01010011" when "00011011",  -- S
         "01010100" when "00101100",  -- T
         "01010101" when "00111100",  -- U
         "01010110" when "00101010",  -- V
         "01010111" when "00011101",  -- W
         "01011000" when "00100010",  -- X
         "01011001" when "00110101",  -- Y
         "01011010" when "00011010",  -- Z

         "01100000" when "00001110",  -- `
         "00101101" when "01001110",  -- -
         "00111101" when "01010101",  -- =
         "01011011" when "01010100",  -- [
         "01011101" when "01011011",  -- ]
         "01011100" when "01011101",  -- \
         "00111011" when "01001100",  -- ;
         "00100111" when "01010010",  -- '
         "00101100" when "01000001",  -- ,
         "00101110" when "01001001",  -- .
         "00101111" when "01001010",  -- /

         "00100000" when "00101001",  -- (space)
         "00001101" when "01011010",  -- (enter, cr)
         "00001000" when "01100110",  -- (backspace)
         "00101010" when others;      -- *
end arch;