process(clk,Xre,Xim,sin,cos)
begin
if(clk'event and clk='1')then -- 一个时钟延迟
xi <= Xre(widthDAT-1 downto 0);
xq <= Xim(widthDAT-1 downto 0);
sin_reg <= sin; cos_reg <= cos;
end if;
end process;
和
process(Xre,Xim,sin,cos)
begin -- 只是缓存一下
xi <= Xre(widthDAT-1 downto 0);
xq <= Xim(widthDAT-1 downto 0);
sin_reg <= sin; cos_reg <= cos;
end process;
上面两种方式对输入信号的处理，哪种方式比较好呢？
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