企业官网建设流程全解析

1、题目

In this question, you will design a circuit for an 8x1 memory, where writing to the memory is accomplished by shifting-in bits, and reading is "random access", as in a typical RAM. You will then use the circuit to realize a 3-input logic function.

First, create an 8-bit shift register with 8 D-type flip-flops. Label the flip-flop outputs from Q[0]...Q[7]. The shift register input should be calledS, which feeds the input of Q[0] (MSB is shifted in first). Theenableinput controls whether to shift. Then, extend the circuit to have 3 additional inputsA,B,Cand an outputZ. The circuit's behaviour should be as follows: when ABC is 000, Z=Q[0], when ABC is 001, Z=Q[1], and so on. Your circuit should contain ONLY the 8-bit shift register, and multiplexers. (Aside: this circuit is called a 3-input look-up-table (LUT)).

2、代码

module top_module ( input clk, input enable, input S, input A, B, C, output Z ); reg [7:0]Q; wire [2:0]addr; always@(posedge clk)begin if(enable) Q<={Q[6:0],S}; else Q<=Q;//防锁存 end assign addr={A,B,C}; assign Z=Q[addr]; endmodule

3、结果