Dear Valued Customers: 

Xilinx has become aware  that a number of  after-market  companies are  offering our  customers “up-screening” services for Xilinx products.  These service providers attempt to elevate the grade level of an IC through the application of post-sale testing and/or screening.   There are high risks associated with this practice for all but the simplest of components. 

For example,  a popular approach is to take commercial (C grade) products and test them at a higher temperature to obtain “I” and “M” grade components. The difference between the various levels of grading involves many variables including operating voltage ranges, leakage current, and speed margins, as well as temperature guardbands. Development of reliable methodologies and test suites for unique VLSI components, such as FPGAs, require specialized expertise and large investments.  Simply re-testing our product to some test program that does not test all the operating modes is not effective or reliable. 

Xilinx  yields  tested  product  at  greater  than six sigma levels of quality.   This has been shown repeatedly by Xilinx data, as well as customers’ data. These levels of quality are achieved by a continuous improvement process incorporating root cause and corrective action.   Xilinx test methodology  is  continuously  evolving  based  on  feedback  and  support  from  over 4,000 customers.  Very few after-market test houses have the required hardware implementation and none have Xilinx methodology. 

Also, our  products  are  extremely  complex,  and  can  be  damaged  by  the  application  of inappropriate configuration fields, voltage or current stresses.  Any third party attempting to test Xilinx devices must have an intimate knowledge of our architecture, circuit implementation, and design methodology.  Without this expertise it is practically impossible to write safe, efficient test code. 

Another practice is to test and certify commercial product outside the manufacturer's maximum ratings.   This is becoming commonplace with plastic encapsulated products.  This practice is extremely dangerous.  Commercial products must not be used outside their published design ratings and intended application. 

Please be advised that Xilinx can not be responsible for any component or system failure due to the use of its products outside of Xilinx published operating parameters and can not warrant any component that has been subjected to “up-screening.” 

To  support  defense  and  other  high reliability applications,  Xilinx  offers a complete  line  of extended-temperature products in both ceramic and plastic packages fully guaranteed by Xilinx.  Reaffirming  our  long-standing  commitment  to  the  Defense and Aerospace markets,  Xilinx has  received  full  QML  certification  in  November of 1997.   Our  new  QPROTM  line  of High-Reliability FPGAs now includes the high density XQ4000XL 3.3V family as well as the XQ4000E 5V family.  All of these products offer the highest cost efficiency, reliability and are available off-the-shelf. 

Sincerely 

Joseph J. Fabula 
Director, Quality Assurance