module pc_unit (
  new_address,
  current_pc,
  clock,
  load,
  incpc
);


output [15:0] current_pc;
reg [15:0] current_pc;
input clock, load, incpc;
input [15:0] new_address;

`include ".\\timing.v"


initial
begin
  current_pc = 0;
end


always@(posedge incpc or posedge load)
case(load)
    0:  begin
          #TPDINC current_pc = current_pc + 1;
          $display("%t: PC incremented %m PC=%h",$time,current_pc);
        end
    1:  begin
          current_pc = new_address;
          $display("%t: PC loaded %m PC=%h",$time,current_pc);
        end
    
    default: $display("%t (%m):Illegal value of load: %b",$time, load);
    endcase

endmodule