National Semiconductor Corp., one of the biggest makers of chips for cellular phones, reported a turnaround profit for its fiscal fourth quarter as demand soared. Profit from operations was $134.2 million, or 68 cents a share, exceeding the 62-cent average estimate of analysts polled by First Call/Thomson Financial. Sales grew 22% to $595.3 million in the period. In the year-earlier quarter, National Semi lost $40 million, or 24 cents a share. The company returned to profitability in its second quarter after six money-losing periods as it focused on communications and stopped making processors for personal computers. Shares of Santa Clara, Calif.-based National Semi rose 25 cents to close at $64.38 on the NYSE.