FOURTH LOAN MODIFICATION AGREEMENT

Exhibit 10.1

FOURTH LOAN MODIFICATION AGREEMENT

This Fourth Loan Modification Agreement (this “Loan Modification Agreement”) is entered into as of August 5, 2009, by and between SILICON VALLEY BANK , a California corporation with its principal place of business at 3003 Tasman Drive, Santa Clara, California 95054 and with a loan production office located at One Newton Executive Park, Suite 200, 2221 Washington Street, Newton, Massachusetts 02462 (“Bank”), and LTX-CREDENCE CORPORATION (formerly known as LTX Corporation), a Massachusetts corporation with its chief executive office located at 1355 California Circle, Milpitas, California 95035 (“Borrower”).

1. DESCRIPTION OF EXISTING INDEBTEDNESS AND OBLIGATIONS . Among other indebtedness and obligations which may be owing by Borrower to Bank, Borrower is indebted to Bank pursuant to a loan arrangement dated as of December 7, 2006, evidenced by, among other documents, a certain Loan and Security Agreement dated as of December 7, 2006, between Borrower and Bank as amended by a First Loan Modification Agreement dated as of February 25, 200, a Second Loan Modification Agreement dated as of March 27, 2009 and a Third Loan Modification Agreement dated as of April 22, 2009 (as amended, the “Loan Agreement”). Capitalized terms used but not otherwise defined herein shall have the same meaning as in the Loan Agreement.

2. DESCRIPTION OF COLLATERAL . Repayment of the Obligations is secured by the Collateral as described in the Loan Agreement (together with any other collateral security granted to Bank, the “Security Documents”). Hereinafter, the Security Documents, together with all other documents evidencing or securing the Obligations, shall be referred to as the “Existing Loan Documents”.

3. DESCRIPTION OF CHANGE IN TERMS .

“(i) Advances . Subject to Section 2.2(b), the principal amount outstanding under the Revolving Line shall accrue interest at a floating per annum rate equal to (A) from the Effective Date through and including that date that is one (1) day prior to the 2009 Effective Date, the Prime Rate less one and one-quarter of one percentage point (1.25%), and (B) from the 2009 Effective Date and thereafter, the Prime Rate, which interest shall be payable monthly in accordance with Section 2.2(f) below.”

and inserting in lieu thereof the following

“(i) Advances . Subject to Section 2.2(b), the principal amount outstanding under the Revolving Line shall accrue interest at a floating per annum rate equal to (A) from the Effective Date through and including that date that is one (1) day prior to the 2009 Effective Date, the Prime Rate less one and one-quarter of one percentage point (1.25%), (B) from the 2009 Effective Date through and including that date that is one (1) day prior to the Fourth Loan Modification Effective Date, the Prime Rate, and (C) from and including the Fourth Loan Modification Effective Date and thereafter, the Prime Rate plus one-half of one percentage point (0.50%), which interest shall be payable monthly in accordance with Section 2.2(f) below.”

“ 6.7 Liquidity . Borrower shall maintain, at all times, Quick Assets in an amount greater than the sum of (a) the outstanding amount of principal and interest under the Term Loan, plus (b) the outstanding Obligations relating to Sections 2.1.1, 2.1.2, 2.1.3, and 2.1.4, plus (c) Twenty Million Dollars ($20,000,000.00), to be tested monthly.”

and inserting in lieu thereof the following:

“ 6.7 Liquidity . Borrower (i) shall maintain, at all times, Quick Assets in an amount greater than the sum of (a) the outstanding Obligations under Sections 2.1.1, 2.1.2, 2.1.3 and 2.1.4, plus (b) Seven Million Dollars ($7,000,000.00), and (ii) shall have, at the end each of Borrower’s fiscal quarters, Quick Assets in an amount greater than the sum of (a) the outstanding Obligations under Sections 2.1.1, 2.1.2, 2.1.3 and 2.1.4, plus (b) Twenty Million Dollars ($20,000,000.00) . In the event Borrower’s Quick Assets at any time are equal to or less than $7,000,000, Borrower will provide to Bank cash collateral in an amount equal to (i) 105% of all outstanding Letters of Credit, if any, plus all interest, fees, and costs due or to become due in connection therewith (as estimated by Bank in its good faith business judgment), to secure all of the Obligations relating to said Letters of Credit, plus (ii) 100% of all outstanding Obligations incurred in connection with Cash Management Services, if any, to secure all of the Obligations relating to said Cash Management Services.”

“ “Fourth Loan Modification Effective Date” is August     , 2009.”

“ “Revolving Line” is an Advance or Advances in an aggregate amount of up to Forty Million Dollars ($40,000,000.00) outstanding at any time.”

and inserting in lieu thereof the following:

“ “Revolving Line” is an Advance or Advances in an aggregate amount of up to Forty Million Dollars ($40,000,000.00) outstanding at any time; provided, however, that (i) during any period in which Borrower’s Quick Assets are less than $20,000,000, but greater than or equal to $19,000,000, the Revolving Line shall be an Advance or Advances in an aggregate amount of up to Thirty Seven Million Five Hundred Thousand Dollars ($37,500,000.00) outstanding at any time, (ii) during any period in which Borrower’s Quick Assets are less than $19,000,000, but greater than or equal to $18,000,000, the Revolving Line shall be an Advance or Advances in an aggregate amount of up to Thirty Five Million Dollars ($35,000,000.00) outstanding at any time, (iii) during any period in which Borrower’s Quick Assets are less than $18,000,000, but greater than or equal to $17,000,000, the Revolving Line shall be an Advance or Advances in an aggregate amount of up to Thirty Two Million Five Hundred Thousand Dollars ($32,500,000.00) outstanding at any time, (iv) during any period in which Borrower’s Quick Assets are less than $17,