20+ câu trắc nghiệm Thiết kế hệ thống số dùng HDL có đáp án

The task $stop is provided to

module mydesign (a,b);

input [1:0] b;

output reg a;

always @(b)

   begin

      if (b==2'b00) a = 1'b0;

      else if (b==2'b11) a = 1'b0;

      else a = 1'b1;

   end

end module

If A = 4b011 and B = 4b0011, then the result of A ** B will be

initial clk = 1’b1;

always #10 clk = ~clk;

initial clk = 1’b0;

always #5 clk = ~clk;

integer x, y;

initial

begin

  x = 15;

  y = 10;

end

initial

  repeat (x) $display (“x=%d”, x);

initial

  while (y < 12)

  begin

    y = y + 1;

    x = x - 1;

  end

module guess (data, cond, result);

input [7:0] data;

input [1:0] cond;

output reg result;

always @(data)

begin

   if (cond == 2’b00)

      result = |data;

   else

      result = ~^data;

end

endmodule

Which of the following are true when the module is synthesized? (multiple choices)

What will the following code segment generate on synthesis, assuming that the four variables data0, data1, data2 and data3 map into four latches/flip-flops?

always @(posedge clock)

begin

data3 = din;

data2 = data3;

data1 = data2;

data0 = data1;

end

What will the following code segment generate on synthesis, assuming that the four variables data0, data1, data2 and data3 map into four latches/flip-flops?

always @(posedge clock)

begin

data3 = din;

data2 = data3;

data1 = data2;

data0 = data1;

end

If A = 4b001x and B = 4b1011, then result of A + B will be

always @(posedge clock)

begin

    y = x;

    z = y;

    x = z;

end

wire [7:0] A;

wire B;

assign B = ~|A;

If the value of A is 8’b00111001, what will be the value of {A[5:3], 3{B}}?

wire [5:0] A, B;

wire C;

assign C=^A;

If the values of A and B are 5’b10011 and 5’b01110 respectively, what will be the value of {A[3:1], 2{C}, B[2:0]}?