architecture simple of switch is
	quantity v across i through p to m;
	quantity reff : real;
	signal r_eff : real := roff;
begin
process (d)
		begin
			if ( d = ‘1’ ) then
				r_eff <= ron;
			else
				r_eff <= roff;
			end if;
		end process;

		reff == r_eff’ramp ( ton, toff );
		i == v / reff;
end;