X0304 4 2010-08-17 false 0000813672 CADENCE DESIGN SYSTEMS INC CDNS 0001008463 TAN LIP BU 2655 SEELY AVENUE, BLDG 5 SAN JOSE CA 95134 true true false false President and CEO Common Stock 31400 I Held By IRA Common Stock 2010-08-17 5 Z false 50001 0 A 238387 I By Trust Common Stock 2010-08-17 5 Z false 50001 0 D 508331 D Common Stock 2011-01-20 5 Z false 75000 0 A 313387 I By Trust Common Stock 2011-01-20 5 Z false 75000 0 D 433331 D Common Stock 2011-02-10 5 Z false 33333 0 A 346720 I By Trust Common Stock 2011-02-10 5 Z false 33333 0 D 399998 D Common Stock 2011-02-15 5 Z false 16668 0 A 363388 I By Trust Common Stock 2011-02-15 5 Z false 16668 0 D 383330 D Common Stock 2011-08-02 4 P false 20000 9.975 A 383388 I By Trust Shares held by IRA FBO Lip-Bu Tan DB Securities Inc. Custodian Rollover Account DTD 5/19/97. Shares transferred to the Lip-Bu Tan and Ysa Loo Trust dated 2/3/1992. Shares transferred to the Lip-Bu Tan and Ysa Loo Trust dated 2/3/1992. Shares transferred to the Lip-Bu Tan and Ysa Loo Trust dated 2/3/1992. Shares transferred to the Lip-Bu Tan and Ysa Loo Trust dated 2/3/1992. Amount of Securities Beneficially Owned Following Reported Transaction includes: (i) 7,000 shares held by L Tan & N Lee &W Lee Trustees, Pacven Walden Inc. 401(k) PSB FBO Lip-Bu Tan; (ii) 371,388 shares held by Lip-Bu Tan and Ysa Loo Trust dated 2/3/1992; adn (iii) 5,000 shares held by A&E Investment LLC, the sole member of which is the Lip-Bu Tan and Ysa Loo Trust dated 2/3/1992. James J. Cowie, Attorney-in-Fact for Lip-Bu Tan 2011-08-04