sao.vhd

硬件出租车记数器完整的VHDL语言设计

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
ENTITY sao IS
	PORT(
		clk			: IN	STD_LOGIC;
		p8		: IN	STD_LOGIC_VECTOR(3 downto 0);
		p7		: IN	STD_LOGIC_VECTOR(3 downto 0);
		p6		: IN	STD_LOGIC_VECTOR(3 downto 0);
		p5		: IN	STD_LOGIC_VECTOR(3 downto 0);
		p4		: IN	STD_LOGIC_VECTOR(3 downto 0);
		p3		: IN	STD_LOGIC_VECTOR(3 downto 0);
		p2		: IN	STD_LOGIC_VECTOR(3 downto 0);
		p1		: IN	STD_LOGIC_VECTOR(3 downto 0);
		choice	: OUT	STD_LOGIC_VECTOR(7 downto 0);
		data	: OUT	STD_LOGIC_VECTOR(7 downto 0));
END sao;

ARCHITECTURE a OF sao IS
	SIGNAL count : STD_LOGIC_VECTOR(2 downto 0);
	SIGNAL temp : STD_LOGIC_VECTOR(3 downto 0);
	SIGNAL choicein, datain		 : STD_LOGIC_VECTOR(7 downto 0);

BEGIN
clk1_label:
PROCESS (clk)
BEGIN
IF clk'event and clk='1' THEN
    count<=count+1;
END IF;
END PROCESS clk1_label;
clk2_label:
PROCESS (clk)
BEGIN
if clk'event and clk='0' then
   choice<=choicein;
   data(7 downto 1)<=datain(7 downto 1);
   if( count="0110" or count="0010" )then data(0)<= '1'; else data(0)<='0'; end if;
END IF;
END PROCESS clk2_label;

choicein<="00000001" when count="000" else
		"00000010" when count="001" else
		"00000100" when count="010" else
		"00001000" when count="011" else
		"00010000" when count="100" else
		"00100000" when count="101" else
		"01000000" when count="110" else
		"10000000" ;
temp<=	p1 when count="000" else
		p2 when count="001" else
		p3 when count="010" else
		p4 when count="011" else
		p5 when count="100" else
		p6 when count="101" else
		p7 when count="110" else
		p8 ;
WITH temp select
	datain  <= "11111100" WHEN "0000",
			   "01100000" WHEN "0001",
			   "11011010" WHEN "0010",
			   "11110010" WHEN "0011",
			   "01100110" WHEN "0100",
			   "10110110" WHEN "0101",
			   "10111110" WHEN "0110",
			   "11100000" WHEN "0111",
			   "11111110" WHEN "1000",
			   "11110110" WHEN "1001",
			   "11101110" WHEN "1010",
			   "00111110" WHEN "1011",
			   "10011100" WHEN "1100",
			   "01111010" WHEN "1101",
			   "10011110" WHEN "1110",
			   "10001110" WHEN OTHERS;

END a;