ledarray_drv.vhd

VHDL基础的编程源代码

--/*****************************************************************************
-- * 源文件:	ledarray_drv.vhd
-- * 模块:   	LED点阵驱动
-- * 版权:
-- *         	Copyright(C) 北京联华众科科技有限公司
-- *						www.lianhua-zhongke.com.cn
-- * 版本：  	Version 1.0
-- * 
-- * 功能说明:
-- *		   	将LED点阵的8*8点阵数据显示在LED点阵设备上
-- *
-- * 参数说明：
-- *	       	输出
-- *			row - 8*8点阵的一行数据
-- *			row_select - 当前行选择数据
-- *
-- *			输入
-- *			row0 - 点阵的 0 行数据
-- *			row1 - 点阵的 1 行数据
-- *			row2 - 点阵的 2 行数据
-- *			row3 - 点阵的 3 行数据
-- *			row4 - 点阵的 4 行数据
-- *			row5 - 点阵的 5 行数据
-- *			row6 - 点阵的 6 行数据
-- *			row7 - 点阵的 7 行数据
-- *			clock - 扫描显示时钟
-- *			reset - 复位信号，低电平有效
-- *
-- *			参数
-- *
-- * 变更记录: 
-- *         2006.01.28, 新建
-- *
-- *****************************************************************************/

LIBRARY ieee;
USE ieee.std_logic_1164.all;
USE ieee.std_logic_arith.all;
USE ieee.std_logic_unsigned.all;

ENTITY ledarray_drv IS
	PORT
	(
		row			: OUT	STD_LOGIC_VECTOR(7 DOWNTO 0);
		row_select	: OUT	STD_LOGIC_VECTOR(7 DOWNTO 0);

		row0		: IN	STD_LOGIC_VECTOR(7 DOWNTO 0);
		row1		: IN	STD_LOGIC_VECTOR(7 DOWNTO 0);
		row2		: IN	STD_LOGIC_VECTOR(7 DOWNTO 0);
		row3		: IN	STD_LOGIC_VECTOR(7 DOWNTO 0);
		row4		: IN	STD_LOGIC_VECTOR(7 DOWNTO 0);
		row5		: IN	STD_LOGIC_VECTOR(7 DOWNTO 0);
		row6		: IN	STD_LOGIC_VECTOR(7 DOWNTO 0);
		row7		: IN	STD_LOGIC_VECTOR(7 DOWNTO 0);
		
		clock		: IN	STD_LOGIC;
		reset		: IN	STD_LOGIC
	);
END ledarray_drv;

ARCHITECTURE ledarray_drv_architecture OF ledarray_drv IS	
BEGIN

	PROCESS(clock, reset)
		VARIABLE next_cs : STD_LOGIC_VECTOR(7 DOWNTO 0);
	BEGIN		
		IF (reset = '0') THEN
			row <= "11111111";
			row_select <= "11111111";
			next_cs := "11111110";
		ELSE 
			IF(clock = '1' AND clock'EVENT) THEN
				row_select <= next_cs;
				
				CASE next_cs IS
					WHEN "11111110" => row <= not row0;
									 next_cs := "11111101";
					WHEN "11111101" => row <= not row1;
									 next_cs := "11111011";
					WHEN "11111011" => row <= not row2;
									 next_cs := "11110111";
					WHEN "11110111" => row <= not row3;
									 next_cs := "11101111";
					WHEN "11101111" => row <= not row4;
									 next_cs := "11011111";
					WHEN "11011111" => row <= not row5;
									 next_cs := "10111111";
					WHEN "10111111" => row <= not row6;
									 next_cs := "01111111";
					WHEN "01111111" => row <= not row7;
									 next_cs := "11111110";
					WHEN OTHERS => row <= "11111111";
								   next_cs := "11111110";
				END CASE;
				
			END IF;
		END IF;
		
	END PROCESS;

END ledarray_drv_architecture;