Elevator Control System Using VHDL

module mylift(req_floor,in_c_floor,clk,reset,complete,direction,out_c_floor);



input[7:0]req_floor;
input[7:0]in_c_floor;
input clk;
input reset;

output direction;
output complete;
output[7:0]out_c_floor;

reg r_direction;
reg r_complete;
reg [7:0]r_out_c_floor;

reg[25:0]clk_count;
reg clk_200;
reg clk_trigger;

assign direction = r_direction;
assign complete = r_complete;
assign out_c_floor = r_out_c_floor;

always@(negedge reset)
begin
clk_200= 1'b0;
clk_count=0;
clk_trigger= 1'b0;

r_complete=1'b0;
end

always@(posedge clk)begin
if(clk_trigger)begin
clk_count=clk_count+1;
end
if(clk_count==499999999)
begin
clk_200=~clk_200;
clk_count=0;
end
end

always@(req_floor)begin
clk_trigger=1;
clk_200=~clk_200;

r_out_c_floor<= in_c_floor;
end


always@(posedge clk)begin
if(!reset)begin
 if(req_floor > r_out_c_floor)begin

  r_direction=1'b1;
  r_out_c_floor <= r_out_c_floor +1;
  end

  else if(req_floor < r_out_c_floor)begin

  r_direction=1'b0;
  r_out_c_floor <= r_out_c_floor - 1 ;
  end
 else if(req_floor == r_out_c_floor)begin

 r_complete=1'b1;
 r_direction=0'b0;
 end
 end
end
endmodule



Test Bench


#10 clk = 1'b1; reset = 1'b0;
#10 reset = 1'b0;
#10 reset = 1'b1;
#10 req_floor = 8'b00101000;   in_c_floor = 8'b00000111;
#10 reset = 1'b1;
#10 reset = 1'b0;
#10 req_floor = 8'b00101000; in_c_floor = 8'b00000111;

// Wait 100 ns for global reset to finish
#100;
     
// Add stimulus here

end
always #10 clk=~clk;
   
endmodule