Exhibit 99.1

CERTIFICATION OF CHIEF EXECUTIVE OFFICER AND CHIEF FINANCIAL OFFICER

PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

I, Bernard Aronson, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that the Quarterly Report of Synplicity, Inc. on Form 10-Q for the quarter ended March 31, 2003 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 and that information contained in such Quarterly Report fairly presents in all material respects the financial condition and results of operations of Synplicity, Inc.

Date:	May 14, 2003	By:	/s/    Bernard Aronson
		Name:	Bernard Aronson
		Title:	Chief Executive Officer, President and Director

I, Douglas S. Miller, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that the Quarterly Report of Synplicity, Inc. on Form 10-Q for the quarter ended March 31, 2003 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 and that information contained in such Quarterly Report fairly presents in all material respects the financial condition and results of operations of Synplicity, Inc.

Date:	May 14, 2003	By:	/s/    Douglas S. Miller
		Name:	Douglas S. Miller
		Title:	Vice President of Finance and Chief Financial Officer