Behavioral Description

BEHAVIORAL DESCRIPTION 

module array_multiplier(A, B, P);

input  [3:0] A, B;

output [7:0] P;

reg    [7:0] P_reg = 0;

assign P = P_reg;

always @(*) 

begin

    P_reg = 0;

    if(B[0] == 1) P_reg = P_reg + (A << 0);

    if(B[1] == 1) P_reg = P_reg + (A << 1);

    if(B[2] == 1) P_reg = P_reg + (A << 2);

    if(B[3] == 1) P_reg = P_reg + (A << 3);

end

endmodule

TEST BENCH:--

module tb_array_multiplier;

reg  [3:0] A, B;

wire [7:0] P;

array_multiplier uut (A, B, P);

initial

begin

    A = 4'b0011; B = 4'b0101; #10;

    A = 4'b1111; B = 4'b0001; #10;

    A = 4'b1010; B = 4'b0011; #10;

    A = 4'b0110; B = 4'b0110; #10;

    A = 4'b1111; B = 4'b1111; #10;

end

endmodule

OUTPUT