组合运算模块的行为设计 entity fir is port(X0, x1, x 2, X3: in integer; hO, h1, h2, h3: in integer, y: out integer end fir: architecture beh of fir is egin y<=x32h0+x2h1+x1h2+x0h3: end beh 综合结果:需要使用15800个LUT组合运算模块的行为设计 entity fir4 is port (x0,x1,x2,x3: in integer; h0,h1,h2,h3: in integer; y: out integer); end fir4; architecture beh of fir4 is begin y<=x3*h0+x2*h1+x1*h2+x0*h3; end beh; 综合结果：需要使用15800个LUT！