Design a BCD converter to drive one (and only one) of the 7-segment displays on
ID: 2318519 • Letter: D
Question
Design a BCD converter to drive one (and only one) of the 7-segment displays on the Basys2 board. For example if a3a2a1a0 = 0011, 3 should appear on the 7-segment display. Write the signal assignments statements for segments a through g using VHDL, as presented in Chapter 10.1 of the text. Implement the converter on the Basys2 board. Remember that the 7-segment displays on the Basys2 board are active-low. Use a VHDL circuit description to do this. Do NOT use Schematic Capture. can you solve it with the circuit.
Explanation / Answer
The VHDL architectural code for BCD to 7-segment decoder is given below:-
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;
entity decoder1 is
port (
clk : in std_logic;
bcd : in std_logic_vector(3 downto 0); --BCD input
segment7 : out std_logic_vector(6 downto 0) -- 7 bit decoded output.
);
end decoder1;
--'a' corresponds to MSB of segment7 and g corresponds to LSB of segment7.
architecture Behavioral of decoder1 is
begin
process (clk,bcd)
BEGIN
if (clk'event and clk='1') then
case bcd is
when "0000"=> segment7 <="0000001"; -- '0'
when "0001"=> segment7 <="1001111"; -- '1'
when "0010"=> segment7 <="0010010"; -- '2'
when "0011"=> segment7 <="0000110"; -- '3'
when "0100"=> segment7 <="1001100"; -- '4'
when "0101"=> segment7 <="0100100"; -- '5'
when "0110"=> segment7 <="0100000"; -- '6'
when "0111"=> segment7 <="0001111"; -- '7'
when "1000"=> segment7 <="0000000"; -- '8'
when "1001"=> segment7 <="0000100"; -- '9'
--nothing is displayed when a number more than 9 is given as input.
when others=> segment7 <="1111111";
end case;
end if;
end process;
end Behavioral;