counter5.vhd

来自「用于视频运动图像编码的HUFFMAN编码」· VHDL 代码 · 共 48 行

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;

entity COUNTER_5 is
	port(	RST: in std_logic;
		CLK: in std_logic;
		COUNTER_Q: out std_logic_vector(4 downto 0);
		CARRY: out std_logic );
end COUNTER_5;

architecture ALG of COUNTER_5 is
	signal CNT1 :std_logic_vector(4 downto 0);
begin
	
	CNT_PROCESS:process(RST,CLK)
	begin 
	if RST='0' then
		CNT1<="00000";
		
	else
		if CLK'event and CLK='1' then
			if CNT1="11111"then 
				CNT1<="00000";
				
			else
				CNT1<=CNT1+1 ;
			end if;
		else
		end if;
	end if;
	
	end process CNT_PROCESS;
	
	COUNTER_Q<=CNT1;
	
	CARRY_PROCESS:process(CNT1)
	begin 
		case CNT1 is
		when "10000"=> CARRY<='0';
		when others=>CARRY<='1';
		end case;
	end process CARRY_PROCESS;
end ALG;