VHDL AND 运算符用法“无运算符“和”的函数声明

Question

我有以下代码：

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.NUMERIC_STD.ALL;
USE IEEE.STD_LOGIC_MISC.ALL;

ENTITY hazard_unit_forwards IS
    PORT (
        i_Rs1E, i_Rs2E : IN STD_LOGIC_VECTOR(4 downto 0);
        i_RdM, i_RdW : IN STD_LOGIC_VECTOR(4 downto 0);
        i_RegWriteM, i_RegWriteW : IN STD_LOGIC;
        o_ForwardAE, o_ForwardBE : OUT STD_LOGIC_VECTOR(1 downto 0)         -- forward A and B to execute stage
    );
END;

ARCHITECTURE behave OF hazard_unit_forwards IS

BEGIN
    -- forwarding logic for Rs1E
    PROCESS(i_Rs1E, i_RdM, i_RdW, i_RegWriteM, i_RegWriteW) BEGIN
        IF(((i_Rs1E = i_RdM) AND i_RegWriteM) AND (i_Rs1E /= "00000")) THEN     -- forward from memory stage
            o_ForwardAE <= "10";
        ELSIF (((i_Rs1E = i_RdW) AND i_RegWriteW) AND (i_Rs1E /= "00000")) THEN -- forward from writeback stage
            o_ForwardAE <= "01";
        ELSE                -- no forwarding (use RF output)
            o_ForwardAE <= "00";
        END IF;
    END PROCESS;
    
    -- forwarding logic for Rs2E
    PROCESS(i_Rs2E, i_RdM, i_RdW, i_RegWriteM, i_RegWriteW) BEGIN
        IF(((i_Rs2E = i_RdM) AND i_RegWriteM) AND (i_Rs2E /= "00000")) THEN     -- forward from memory stage
            o_ForwardBE <= "10";
        ELSIF (((i_Rs2E = i_RdW) AND i_RegWriteW) AND (i_Rs2E /= "00000")) THEN -- forward from writeback stage
            o_ForwardBE <= "01";
        ELSE                -- no forwarding (use RF output)
            o_ForwardBE <= "00";
        END IF;
    END PROCESS;
END;

VHDL 类型给了我一个 PTSD，我确信这是类型的问题，但不知道哪里出了问题。

GHDL 给我以下错误：

hazard_unit_forwards.vhd:20:37:error: no function declarations for operator "and"
hazard_unit_forwards.vhd:22:41:error: no function declarations for operator "and"
hazard_unit_forwards.vhd:31:37:error: no function declarations for operator "and"
hazard_unit_forwards.vhd:33:41:error: no function declarations for operator "and"

那么，怎么了？

（代码中基本上到处都是AND操作符）

Answer 1

你可以像这样改变 If 语句：

 (((i_Rs1E = i_RdM) AND (i_RegWriteM = '1') AND (i_Rs1E /= "00000"))

我希望这对你有用。