charlib8_8.vhd

VHDL基础的编程源代码

--/*****************************************************************************
-- * 源文件:	charlib8_8.vhd
-- * 模块:   	8*8点字符库
-- * 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ASCII码数据转换为8*8点阵显示数据
-- *
-- * 参数说明：
-- *	       	输出
-- *			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
-- *
-- *			输入
-- *			ext_char_data - 准备显示的ASCII码
-- *			ext_char_index - 准备显示的ASCII码的内部索引
-- *			mode - 确定上面两个输入中哪一个有效
-- *				   1 - ext_char_data 有效
-- *				   0 - ext_char_index 有效
-- *			reset - 复位信号，低电平有效
-- *
-- *			参数
-- *			element_count - 本字库中存放在字符个数，在按内部索引检索显示时作
-- *							为内部索引的边界 
-- *
-- * 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 charlib8_8 IS
	GENERIC
	(
		element_count : INTEGER:= 222
	);
	
	PORT
	(
		row0 : OUT STD_LOGIC_VECTOR(7 downto 0);
		row1 : OUT STD_LOGIC_VECTOR(7 downto 0);
		row2 : OUT STD_LOGIC_VECTOR(7 downto 0);
		row3 : OUT STD_LOGIC_VECTOR(7 downto 0);
		row4 : OUT STD_LOGIC_VECTOR(7 downto 0);
		row5 : OUT STD_LOGIC_VECTOR(7 downto 0);
		row6 : OUT STD_LOGIC_VECTOR(7 downto 0);
		row7 : OUT STD_LOGIC_VECTOR(7 downto 0);

		ext_char_index : IN STD_LOGIC_VECTOR(3 downto 0);
		mode : IN STD_LOGIC;
		reset : IN STD_LOGIC
	);

END charlib8_8;

ARCHITECTURE charlib8_8_architecture OF charlib8_8 IS	
BEGIN
	
	PROCESS(ext_char_index, mode, reset)
	BEGIN		
		IF (reset = '0') THEN
			row0 <= "11111111";
			row1 <= "11111111";
			row2 <= "11111111";
			row3 <= "11111111";
			row4 <= "11111111";
			row5 <= "11111111";
			row6 <= "11111111";
			row7 <= "11111111";
		ELSE
			IF (mode = '1') THEN
				row0 <= "11111111";
				row1 <= "11111111";
				row2 <= "11111111";
				row3 <= "11111111";
				row4 <= "11111111";
				row5 <= "11111111";
				row6 <= "11111111";
				row7 <= "11111111";
			ELSE			
				CASE ext_char_index IS
					WHEN X"0" => 
row0 <= "00111000";
row1 <= "01000100";
row2 <= "01000100";
row3 <= "01000100";
row4 <= "01000100";
row5 <= "01000100";
row6 <= "01000100";
row7 <= "00111000";
					WHEN X"1" => 
row0 <= "00110000";
row1 <= "00010000";
row2 <= "00010000";
row3 <= "00010000";
row4 <= "00010000";
row5 <= "00010000";
row6 <= "00010000";
row7 <= "00111000";
					WHEN X"2" => 
row0 <= "00111000";
row1 <= "01000100";
row2 <= "00000100";
row3 <= "00000100";
row4 <= "00001000";
row5 <= "00010000";
row6 <= "00100010";
row7 <= "01111100";
--						WHEN X"3" => 
--row0 <= "00111000";
--row1 <= "01000100";
--row2 <= "00000100";
--row3 <= "00011000";
--row4 <= "00000100";
--row5 <= "00000100";
--row6 <= "00000100";
--row7 <= "01111000";
--					WHEN X"04" => 
--row0 <= "00001000";
--row1 <= "00011000";
--row2 <= "00101000";
--row3 <= "00101000";
--row4 <= "01001000";
--row5 <= "01111100";
--row6 <= "00001000";
--row7 <= "00001000";
--					WHEN X"05" => 
--row0 <= "00011100";
--row1 <= "00100000";
--row2 <= "00110000";
--row3 <= "00001000";
--row4 <= "00000100";
--row5 <= "00000100";
--row6 <= "00000100";
--row7 <= "01111000";
--					WHEN X"06" => 
--row0 <= "00001100";
--row1 <= "00110000";
--row2 <= "00100000";
--row3 <= "01011000";
--row4 <= "01100100";
--row5 <= "01000100";
--row6 <= "01000100";
--row7 <= "00111000";
--					WHEN X"07" => 
--row0 <= "00111100";
--row1 <= "01000100";
--row2 <= "00000100";
--row3 <= "00001000";
--row4 <= "00001000";
--row5 <= "00001000";
--row6 <= "00010000";
--row7 <= "00010000";
--					WHEN X"08" => 
--row0 <= "00111000";
--row1 <= "01000100";
--row2 <= "01000100";
--row3 <= "00111000";
--row4 <= "00101000";
--row5 <= "01000100";
--row6 <= "01000100";
--row7 <= "00111000";
--					WHEN X"09" => 
--row0 <= "00111000";
--row1 <= "01000100";
--row2 <= "01000100";
--row3 <= "01000100";
--row4 <= "00111100";
--row5 <= "00001000";
--row6 <= "00011000";
--row7 <= "01100000";
					WHEN OTHERS =>
row0 <= "11111111";
row1 <= "11111111";
row2 <= "11111111";
row3 <= "11111111";
row4 <= "11111111";
row5 <= "11111111";
row6 <= "11111111";
row7 <= "11111111";
				END CASE;
			END IF;
			
		END IF;
		
	END PROCESS;

END charlib8_8_architecture;