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library ieee;
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library ieee;
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use ieee.std_logic_1164.all;
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use ieee.std_logic_1164.all;
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use work.mlite_pack.all;
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use work.mlite_pack.all;
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entity alu is
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entity alu is
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generic(adder_type : string := "GENERIC";
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generic(adder_type : string := "DEFAULT";
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alu_type : string := "GENERIC");
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alu_type : string := "DEFAULT");
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port(a_in : in std_logic_vector(31 downto 0);
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port(a_in : in std_logic_vector(31 downto 0);
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b_in : in std_logic_vector(31 downto 0);
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b_in : in std_logic_vector(31 downto 0);
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alu_function : in alu_function_type;
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alu_function : in alu_function_type;
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c_alu : out std_logic_vector(31 downto 0));
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c_alu : out std_logic_vector(31 downto 0));
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end; --alu
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end; --alu
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sign_ext <= '0' when alu_function = ALU_LESS_THAN else '1';
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sign_ext <= '0' when alu_function = ALU_LESS_THAN else '1';
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aa <= (a_in(31) and sign_ext) & a_in;
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aa <= (a_in(31) and sign_ext) & a_in;
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bb <= (b_in(31) and sign_ext) & b_in;
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bb <= (b_in(31) and sign_ext) & b_in;
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-- synthesis translate_off
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-- synthesis translate_off
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GENERIC_ALU: if alu_type = "GENERIC" generate
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GENERIC_ALU: if alu_type = "DEFAULT" generate
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-- synthesis translate_on
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-- synthesis translate_on
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c_alu <= sum(31 downto 0) when alu_function=ALU_ADD or alu_function=ALU_SUBTRACT else
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c_alu <= sum(31 downto 0) when alu_function=ALU_ADD or alu_function=ALU_SUBTRACT else
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ZERO(31 downto 1) & sum(32) when alu_function=ALU_LESS_THAN or alu_function=ALU_LESS_THAN_SIGNED else
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ZERO(31 downto 1) & sum(32) when alu_function=ALU_LESS_THAN or alu_function=ALU_LESS_THAN_SIGNED else
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a_in or b_in when alu_function=ALU_OR else
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a_in or b_in when alu_function=ALU_OR else
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c_alu <= a_in nor b_in when alu_function=ALU_NOR else (others => 'Z');
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c_alu <= a_in nor b_in when alu_function=ALU_NOR else (others => 'Z');
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c_alu <= ZERO when alu_function=ALU_NOTHING else (others => 'Z');
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c_alu <= ZERO when alu_function=ALU_NOTHING else (others => 'Z');
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end generate;
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end generate;
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generic_adder: if adder_type = "GENERIC" generate
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generic_adder: if adder_type = "DEFAULT" generate
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sum <= bv_adder(aa, bb, do_add);
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sum <= bv_adder(aa, bb, do_add);
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end generate; --generic_adder
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end generate; --generic_adder
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--For Altera
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--For Altera
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lpm_adder: if adder_type = "ALTERA" generate
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lpm_adder: if adder_type = "ALTERA" generate
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