Question

代码的功能被赋予一个操作码，它将在时钟的上升沿执行任务。我是本科二年级学生，所以任何帮助/投入都会感激

library IEEE; 
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.NUMERIC_STD.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;
entity ALU is   Port (
   X,Y     :IN BIT_VECTOR(2 downto 0);
   OPcode  :IN BIT_VECTOR(2 downto 0);
   Z       :OUT BIT_VECTOR(5 downto 0);
   CLK     :IN BIT;
   TempValX:INOUT BIT_VECTOR(5 downto 0)); 
end ALU;
architecture Circuit of ALU is signal g: BIT_VECTOR(3 downto 0);
signal C: BIT_VECTOR(3 downto 0);
signal p, u, r : bit_vector(2 downto 0);
signal s: Bit_vector(5 downto 0);
Component ThreeBitFA is
       PORT (X,Y   :IN BIT_VECTOR(2 downto 0);
               C   :INOUT BIT_VECTOR(3 downto 0));
   end component; begin adder:ThreeBitFA port map(
           X => X,
           Y => Y,
           C => C);
Process(X,Y,CLK,OPcode)
begin
     IF OPcode = "000" THEN ----------------ADD OPcode
       IF (CLK'EVENT AND CLK = '1') THEN
           tempvalx <= "00" & C;
                     Z <= tempvalx;
       end if;
     ELSIF OPcode = "001" THEN ----------------MULT OPcode
       IF (CLK'EVENT AND CLK = '1') THEN
          IF Y(0) = '1' THEN P <= X; ELSE P <= "000"; END IF;
          IF Y(1) = '1' THEN u <= X; ELSE u <= "000"; END IF;
          IF Y(2) = '1' THEN R <= X; ELSE R <= "000"; END IF;
       z(0) <= P(0); 
       z(1) <= P(1) XOR u(0); s(0) <= P(1) AND u(0);
       z(2) <= P(2) XOR u(1) XOR R(0) XOR s(0); s(1) <= s(0) AND P(2); s(2) <= u(1) AND R(0);
       z(3) <= u(2) XOR R(1) XOR s(1) XOR s(2); s(3) <= s(2) AND s(1); s(4) <= u(2) AND R(1);
       z(4) <= R(2) XOR s(3) XOR s(4); s(5) <= s(3) AND s(4); 
       z(5) <= s(5);
       end if;

     ELSIF (OPcode = "010") THEN ------------AND OPcode
       IF (CLK'EVENT AND CLK = '1') THEN
           Z <= "000" & (X AND Y);
       end IF;
     ELSIF (OPcode = "011") THEN ------------OR  Opcode
       IF (CLK'EVENT AND CLK = '1') THEN
           Z <= "000" & (X OR Y);
       end IF;
     ELSIF (OPcode = "100") THEN ------------XOR Opcode
       IF (CLK'EVENT AND CLK = '1') THEN
           Z <= "000" & (X XOR Y);
       end IF;
     ELSIF (OPcode = "101") THEN ------------NOT Opcode
       IF (CLK'EVENT AND CLK = '1') THEN
           Z <= "000" & (NOT X);
       end IF;
     ELSIF (OPcode = "110") THEN -----------Rshift OPcode
       IF (CLK'EVENT AND CLK = '1') THEN
           TempValX <= "000" & X;
           Z <= '0' & TempValX(5 downto 1);
     ELSIF (OPcode = "111") THEN -----------Lshift OPcode
       IF (CLK'EVENT AND CLK = '1') THEN
            TempValX <= "000" & X;
           Z <= TempValX(4 downto 0) & '0';
       end IF;   
     ELSE
          Null;
     END IF;  
   END IF; END Process; end Circuit;

Answer 1

事物脱颖而出。

如果只需要“在时钟的上升沿执行任务”，则只需要在过程敏感性列表中使用“ CLK”即可。
该过程中if-else中的优先顺序是错误的。所有操作码解码逻辑都应位于上升沿时钟检查中。

VHDL编码错误“不支持检查时钟后的其他子句”

1 个答案: