Write a testbench stimulus for the below 8-bit Shift-Left Register with Positive-Edge Clock, Serial In and Serial Out. Start with all ones after the 8th=bit shifted to the left all zeros.
module left_shifter(SHIFTEN, DIN, DOUT);
input SHIFTEN,DIN;
output DOUT;
reg [7:0] tmp;
always @(posedge SHIFTEN)
begin
tmp <= tmp << 1;
tmp[0] <= DIN;
end
assign DOUT = tmp[7];