PDF SOLUTIONS INC — Director's Dealing 2008

Aug 21, 2008

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: PDF SOLUTIONS INC (PDFS)
CIK: 0001120914
Period of Report: 2008-08-18

Reporting Person: Caulfield Thomas (Director)

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2008-08-18	2001 Stock Plan Option (right to buy)	$12.98	D	30000	Disposed	2016-08-29	Common Stock (30000)	Direct
2008-08-18	2001 Stock Plan Option (right to buy)	$10.43	D	15000	Disposed	2017-05-29	Common Stock (15000)	Direct
2008-08-18	Restricted Stock Right	$	A	7143	Acquired		Common Stock (7143)	Direct
2008-08-18	Restricted Stock Right	$	A	3572	Acquired		Common Stock (3572)	Direct

Footnotes

F1: The cancelled option provided for vesting as follows: 12/48ths of the total shares subject to the option vested on September 15, 2007 and 1/48th of the total shares vested on the 15th day of each month thereafter, subject to the reporting person's continued service with PDF Solutions, Inc., or an eligible affiliate thereof, through each vesting date and subject to accelerated vesting in certain circumstances.

F2: Pursuant to PDF Solutions, Inc.'s offer to exchange described in Schedule TO-1 filed on June 10, 2008, as amended (the "Exchange Offer") on August 18, 2008, PDF Solutions, Inc. cancelled an option granted to the reporting person on September 16, 2006. In exchange for the option, the reporting person received 7,143 restricted stock rights.

F3: The cancelled option provided for vesting as follows: 12/48ths of the total shares subject to the option vested on May 30, 2008 and 1/48th of the total shares vested on the 30th day of each month thereafter, subject to the reporting person's continued service with PDF Solutions, Inc. or an eligible affiliate thereof, through each vesting date and subject to accelerated vesting in certain circumstances.

F4: Pursuant to the Exchange Offer, on August 18, 2008, PDF Solutions, Inc. cancelled an option granted to the reporting person on May 27, 2008. In exchange for the option, the reporting person received 3,572 restricted stock rights.

F5: Each restricted stock right ("RSR") represents a bookkeeping entry equal in value to one (1) share of common stock of PDF Solutions, Inc.

F6: 12.5% of the total number of rights will vest on May 15, 2009 and 12.5% will vest every six (6) months thereafter, subject to the reporting person's continued service with PDF Solutions, Inc., or an eligible affiliate thereof, through each vesting date and subject to accelerated vesting in certain circumstances. The RSR will be automatically settled in shares upon vesting of the RSR.