我正在设计通用移位算术运算符。除了以下面介绍的方式使用 32 位多路复用器(解码器)之外,还有更好的方法来实现它吗?
ENTITY isra IS
PORT (
clk: in std_logic;
rst: in std_logic;
di: in std_logic_vector (31 downto 0);
sel: in std_logic_vector (31 downto 0);
res: out std_logic_vector (31 downto 0) := (others => '0')
);
END isra;
PROCESS
BEGIN
WAIT UNTIL clk'EVENT AND clk = '1';
IF rst = '1' THEN
res <= (others => '0');
ELSE
CASE sel IS
when X"00000001" => res <= to_stdlogicvector(to_bitvector(a) sra 1);
when X"00000002" => res <= to_stdlogicvector(to_bitvector(a) sra 2);
...
when X"0000001F" => res <= to_stdlogicvector(to_bitvector(a) sra 31);
when others => res <= (others => '0');
END CASE;
END IF;
END PROCESS;