大家帮忙看看这道题怎么做?
四位运算器框图如图A1.1所示,ALU为算术逻辑单元,A和B为三选一多路开关,预先已通过多路开关A的SW门向寄存器R1,R2送入数据如下:R1=0101,R2=1010.寄存器BR输出端接四个发光二极管进行显示。其运算过程依次如下:⑴R1(A)+R2(B)→BR(1010);⑵R2(A)+R1(B)→BR(1111);⑶R1(A)+R1(B)→BR(1010);⑷R2(A)+R2(B)→BR(1111);⑸R2(A)+BR(B)→BR(1111);⑹R1(A)+BR(