school/ecen320/tx_encoder/seven_segment_display.vhd

78 lines
2.2 KiB
VHDL

library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
entity seven_segment_display is
generic(
COUNTER_BITS: natural := 15
);
port(
clk: in std_logic;
data_in: in std_logic_vector(15 downto 0);
dp_in: in std_logic_vector(3 downto 0);
blank: in std_logic_vector(3 downto 0);
seg: out std_logic_vector(6 downto 0);
dp: out std_logic;
an: out std_logic_vector(3 downto 0)
);
end seven_segment_display;
architecture seven_arch of seven_segment_display is
--signal which_sym: std_logic_vector(3 downto 0);
signal mydatain, an_temp: std_logic_vector(3 downto 0);
signal r_reg: unsigned(COUNTER_BITS-1 downto 0):=(others=>'0');
signal r_next: unsigned(COUNTER_BITS-1 downto 0);
signal anode_select: std_logic_vector(1 downto 0);
begin
--register
process(clk)
begin
if clk'event and clk='1' then
r_reg <= r_next;
end if;
end process;
--next-state logic
process(r_reg)
begin
r_next <= r_reg+1;
end process;
anode_select <= std_logic_vector(r_reg(COUNTER_BITS-1 downto COUNTER_BITS-2));
with mydatain select
seg <= "1000000" when "0000",
"1111001" when "0001",
"0100100" when "0010",
"0110000" when "0011",
"0011001" when "0100",
"0010010" when "0101",
"0000010" when "0110",
"1111000" when "0111",
"0000000" when "1000",
"0010000" when "1001",
"0001000" when "1010",
"0000011" when "1011",
"1000110" when "1100",
"0100001" when "1101",
"0000110" when "1110",
"0001110" when others;
mydatain <= data_in(3 downto 0) when anode_select = "00" else
data_in(7 downto 4) when anode_select = "01" else
data_in(11 downto 8) when anode_select = "10" else
data_in(15 downto 12);
dp <= not dp_in(0) when anode_select="00" else
not dp_in(1) when anode_select="01" else
not dp_in(2) when anode_select="10" else
not dp_in(3);
an_temp <= "1110" when anode_select="00" else
"1101" when anode_select="01" else
"1011" when anode_select="10" else
"0111" when anode_select="11" else
"0000";
an <= an_temp or blank;
end seven_arch;