Question

用VHDL语言实现8位流水灯控制器

1、系统晶振为50MHz，流水灯输入时钟为1Hz，即每秒钟变化一次；
2、流水灯输出为8位显示，每次仅一个灯亮；
3、用至少两种方法来设计流水灯的各部分功能模块（如：可以用元件例化的方法，或者用多进程的设计方法等等）。

Answer 1

Use Shift Registers, you can have a switch to choose shift left or shift right.

I will give you some ideas, MODIFY it yourself:
Change the code to make "start" and "stop" logic work.
--------------------------
library ieee ;
use ieee.std_logic_1164.all;

entity mylight is
port (start : in std_logic;
stop : in std_logic;
shift_left : in std_logic;
Q : out std_logic_vector(7 downto 0)
);
end mylights;

architechture behavior of mylights is

signal lights : std_logic_vector(7 downto 0);

process (clk, start, stop, shift_left)
begin
if (start = '0' or stop = '1') then
lights <= (others => '1');
elsif (clk'event and clk = '1') then
if (shift_left = '1') then
lights <= lights(6 downto 0) & '0';
else
lights <= '0' & lights(7 downto 1);
end;
end;
end process;

Q <= lights;

end behavior;

Answer 2

绝对是cuit的~~

Answer 3

肯定是cuit的

Answer 4

dfasvr2EGH