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(root)//Designs/HAM_Constructions/SDRX02A/HDL/modules/sychro1/up_counter_stdlv.vhd

Rev 4962

library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;

entity up_counter_stdlv is
generic (
        G_BITS : positive := 8; 
        G_MIN_NUMBER : std_logic_vector;
        G_MAX_NUMBER : std_logic_vector
        
        );
port (

        i_clk   : in std_logic;
        i_rst : in std_logic;
        
  -- Count when this input is '1'
  i_valid : in std_logic;
   
   -- Output the actual number
        o_data : out std_logic_vector( G_BITS-1 downto 0 );
        o_carry : out std_logic := '0'
        
   );
end up_counter_stdlv;

architecture rtl of up_counter_stdlv is

signal number : std_logic_vector( G_BITS-1 downto 0 );

begin

        o_data <= number;
        
        counter : process( i_clk )
        begin
        
                if( rising_edge( i_clk ) ) then
                
                        o_carry <= '0';
                
                        if( i_rst = '1' ) then
                                number <= G_MIN_NUMBER;
                        elsif( i_valid = '1' ) then
                                -- count up:
                                if( number = G_MAX_NUMBER ) then
                                        number <= G_MIN_NUMBER;
                                        o_carry <= '1';
                                else
                                        number <= std_logic_vector( unsigned(number) + to_unsigned(1,G_BITS) );
                                end if;
                        end if;
                        
                end if;
        end process;
                                        
end architecture;