FPGA/HDLBits

Tb/and

장영현 2023. 6. 20. 01:20
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You are given the following AND gate you wish to test:

module andgate (
    input [1:0] in,
    output out
);

Write a testbench that instantiates this AND gate and tests all 4 input combinations, by generating the following timing diagram:

module top_module();
    reg [1:0] in;
    wire out;
    
    initial begin
        in[0] = 0;
        in[1] = 0;
        
        #10
        in[0] = ~in[0];
        
        #10
        in[1] = ~in[1];
        in[0] = ~in[0];
        
        #10
        in[0] = ~in[0];
    end
    
    andgate a_gate (.in(in) , .out(out));
endmodule