<TABLE> <S> <C>
<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE ANNUAL
REPORT ON FORM 10-K FOR THE YEAR ENDED MARCH 31, 2000 AND IS QUALIFIED IN ITS
ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
<S> <C> <C>
<PERIOD-TYPE> 12-MOS 12-MOS
<FISCAL-YEAR-END> MAR-31-1999 MAR-31-2000
<PERIOD-START> APR-01-1998 APR-01-1999
<PERIOD-END> MAR-31-1999 MAR-31-2000
<CASH> 13,530 170,102
<SECURITIES> 73,010 784,449
<RECEIVABLES> 19,452 24,773
<ALLOWANCES> 177 314
<INVENTORY> 9,813 10,925
<CURRENT-ASSETS> 125,020 1,005,404
<PP&E> 58,708 80,278
<DEPRECIATION> 35,580 42,436
<TOTAL-ASSETS> 150,655 1,046,882
<CURRENT-LIABILITIES> 21,403 27,783
<BONDS> 7,558 5,294
0 0
0 0
<COMMON> 1,064 1,218
<OTHER-SE> 120,630 1,012,587
<TOTAL-LIABILITY-AND-EQUITY> 150,655 1,046,882
<SALES> 105,000 172,352
<TOTAL-REVENUES> 105,000 172,352
<CGS> 37,937 50,218
<TOTAL-COSTS> 37,937 50,218
<OTHER-EXPENSES> 43,147 61,014
<LOSS-PROVISION> 50 150
<INTEREST-EXPENSE> 542 643
<INCOME-PRETAX> 27,366 73,992
<INCOME-TAX> 10,233 25,367
<INCOME-CONTINUING> 17,133 48,625
<DISCONTINUED> 0 0
<EXTRAORDINARY> 0 0
<CHANGES> 0 0
<NET-INCOME> 17,133 48,625
<EPS-BASIC> 0.17 0.45
<EPS-DILUTED> 0.16 0.41
</TABLE>