downcnt.vhd

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--downcnt.vhd n modules downcounter
library ieee ;
use ieee.std_logic_1164.all ;
entity downcnt is
generic ( modulus : integer := 8 ) ;
port (
	clock : in std_logic ;
	e : in std_logic ;--enable 1->enable 0->disable
	l : in std_logic ;--load 1->load
	q : out	integer range 0 to modulus-1 ) ;
end downcnt ;
architecture behavior of downcnt is
	signal count : integer range 0 to modulus-1 ;
begin
  process
  begin
    wait until (clock'event and clock = '1') ;--clock positive edge trigger
	  if e = '1' then
		if l = '1' then
          count <= modulus-1 ;--loading
		else
		  count <= count-1 ;--counting
		end if ;
	end if ;
  end process;
	q <= count ;--output internal signal
end behavior ;