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75 lines
1.6 KiB
75 lines
1.6 KiB
library ieee;
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use ieee.std_logic_1164.all;
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use ieee.numeric_std.all;
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entity counter is
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generic (
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InitVal : natural := 0;
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EndVal : natural := 16;
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Formal : boolean := true
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);
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port (
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Reset_n_i : in std_logic;
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Clk_i : in std_logic;
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Data_o : out std_logic_vector(31 downto 0)
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);
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end entity counter;
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architecture rtl of counter is
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begin
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process (Reset_n_i, Clk_i) is
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begin
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if (Reset_n_i = '0') then
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Data_o <= std_logic_vector(to_unsigned(InitVal, Data_o'length));
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elsif (rising_edge(Clk_i)) then
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if (to_integer(unsigned(Data_o)) < EndVal) then
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Data_o <= std_logic_vector(unsigned(Data_o) + 1);
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end if;
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end if;
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end process;
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FormalG : if Formal generate
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signal s_data : unsigned(Data_o'range);
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begin
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-- VHDL helper logic
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process is
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begin
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wait until rising_edge(Clk_i);
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s_data <= unsigned(Data_o);
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end process;
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default clock is rising_edge(Clk_i);
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-- Initial reset
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INITIAL_RESET : restrict {Reset_n_i = '0'[*2]; Reset_n_i = '1'[+]}[*1];
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AFTER_RESET : assert always
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not Reset_n_i -> Data_o = (Data_o'range => '0');
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COUNT_UP : assert always
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Reset_n_i and unsigned(Data_o) < to_unsigned(EndVal, 32) -> next unsigned(Data_o) = s_data + 1;
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END_VALUE : assert always
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unsigned(Data_o) = to_unsigned(EndVal, 32) -> next unsigned(Data_o) = s_data;
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VALID_RANGE : assert always
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unsigned(Data_o) >= to_unsigned(InitVal, 32) and
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unsigned(Data_o) <= to_unsigned(EndVal, 32);
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end generate FormalG;
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end architecture rtl;
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