148 lines
5.1 KiB
VHDL
148 lines
5.1 KiB
VHDL
library ieee;
|
|
use ieee.std_logic_1164.all;
|
|
use ieee.numeric_std.all;
|
|
|
|
entity scrolling_controller is
|
|
port(
|
|
clk : in std_logic;
|
|
rst : in std_logic;
|
|
on_off : in std_logic;
|
|
cnt_start : out std_logic;
|
|
cnt_done : in std_logic;
|
|
next_char : out std_logic;
|
|
hex_char : in std_logic_vector(4 downto 0);
|
|
seg_data : out std_logic_vector(3 downto 0);
|
|
seg_off : out std_logic;
|
|
seg_shift : out std_logic;
|
|
seg_write : out std_logic;
|
|
seg_clear : out std_logic;
|
|
buffer_elements : in std_logic_vector(4 downto 0)
|
|
);
|
|
end entity scrolling_controller;
|
|
|
|
architecture Behavioral of scrolling_controller is
|
|
|
|
type state_type is (s_off, s_wait, s_update);
|
|
signal state : state_type;
|
|
|
|
signal sig_seg_shift : std_logic;
|
|
signal sig_seg_write : std_logic;
|
|
signal sig_seg_clear : std_logic;
|
|
|
|
signal current_element : integer range 0 to 16;
|
|
signal current_resetted : std_logic;
|
|
|
|
begin
|
|
|
|
process(clk)
|
|
begin
|
|
if clk'event and clk='1' then
|
|
if rst = '1' then
|
|
state <= s_off;
|
|
cnt_start <= '0';
|
|
next_char <= '0';
|
|
|
|
sig_seg_shift <= '0';
|
|
sig_seg_write <= '0';
|
|
sig_seg_clear <= '0';
|
|
|
|
current_element <= 0;
|
|
current_resetted <= '0';
|
|
else
|
|
case state is
|
|
when s_off =>
|
|
current_element <= 0;
|
|
|
|
if on_off = '0' then
|
|
state <= s_off;
|
|
sig_seg_shift <= '0';
|
|
sig_seg_write <= '0';
|
|
sig_seg_clear <= '0';
|
|
cnt_start <= '0';
|
|
next_char <= '0';
|
|
else
|
|
state <= s_wait;
|
|
sig_seg_shift <= '0';
|
|
sig_seg_write <= '0';
|
|
sig_seg_clear <= '0';
|
|
cnt_start <= '1';
|
|
next_char <= '0';
|
|
end if;
|
|
when s_wait =>
|
|
if on_off = '1' then
|
|
state <= s_off;
|
|
sig_seg_clear <= '1';
|
|
cnt_start <= '0';
|
|
next_char <= '0';
|
|
elsif cnt_done = '0' then
|
|
state <= s_wait;
|
|
sig_seg_shift <= '0';
|
|
sig_seg_write <= '0';
|
|
sig_seg_clear <= '0';
|
|
cnt_start <= '0';
|
|
next_char <= '0';
|
|
else -- cnt_done = '1'
|
|
state <= s_update;
|
|
sig_seg_shift <= '0';
|
|
sig_seg_write <= '0';
|
|
sig_seg_clear <= '0';
|
|
cnt_start <= '1';
|
|
|
|
if current_element < unsigned(buffer_elements) then
|
|
next_char <= '1';
|
|
end if;
|
|
|
|
current_resetted <= '0';
|
|
if current_element = 15 then
|
|
current_element <= 0;
|
|
current_resetted <= '1';
|
|
else
|
|
current_element <= current_element + 1;
|
|
end if;
|
|
end if;
|
|
when s_update =>
|
|
if on_off = '0' then
|
|
state <= s_wait;
|
|
sig_seg_shift <= '1';
|
|
sig_seg_write <= '1';
|
|
sig_seg_clear <= '0';
|
|
cnt_start <= '0';
|
|
next_char <= '0';
|
|
else
|
|
state <= s_off;
|
|
sig_seg_clear <= '1';
|
|
cnt_start <= '0';
|
|
next_char <= '0';
|
|
end if;
|
|
end case;
|
|
end if;
|
|
end if;
|
|
end process;
|
|
|
|
process(clk)
|
|
begin
|
|
if clk'event and clk='1' then
|
|
if rst = '1' then
|
|
seg_data <= (others => '0');
|
|
seg_off <= '0';
|
|
seg_shift <= '0';
|
|
seg_write <= '0';
|
|
seg_clear <= '1';
|
|
else
|
|
if current_element < unsigned(buffer_elements) and not (current_resetted = '1' and unsigned(buffer_elements) /= 16) then
|
|
seg_data <= hex_char(3 downto 0);
|
|
seg_off <= hex_char(4);
|
|
else
|
|
seg_data <= x"0";
|
|
seg_off <= '1';
|
|
end if;
|
|
|
|
seg_clear <= sig_seg_clear;
|
|
seg_write <= sig_seg_write;
|
|
seg_shift <= sig_seg_shift;
|
|
end if;
|
|
end if;
|
|
end process;
|
|
|
|
end Behavioral;
|