The patented invention are methods and apparatus for selectively masking off unknown ('X') captured scan data in scan cells from propagating through the scan chains for test, debug, diagnosis, and yield improvement of a scan-based integrated circuit in scan-test mode or self-test mode. The method and apparatus further includes an output-mask controller and an output-mask network embedded on the scan data input path of scan cells, or a set/reset controller controlling set/reset inputs of selected scan cells. A synthesis method is also proposed for synthesizing the output-mask controller and the set/reset controller. The patented inventions are used in SynTest products VirtualScan for ATPG pattern compression and TurboBIST-Logic for self-test, in use worldwide today, resulting in improved yield, productivity and time-to-market (TTM). The patented inventions also aid in improved debug and diagnosis of integrated circuit.
About SynTest
SynTest Technologies, Inc., established in 1990, develops intellectual properties (IPs) for advanced design-for-test (DFT) and design-for-debug/diagnosis (DFD) applications and markets them throughout the world, to semiconductor companies, system houses and design service providers. The company has filed more than 25 US/PCT patents of which 4 have been issued and 2 allowed. The Company's products improve an electronic design's quality and reduce overall design and test costs. Various applications that use these IPs include logic BIST, memory BIST, boundary-scan synthesis, scan/ATPG with test compression, concurrent fault simulation, silicon debug and diagnosis. The company, headquartered in Sunnyvale, California, has offices in Taiwan, Japan, Korea and China, and distributors in Europe and Asia including Israel. More information is available at www.syntest.com.
SynTest Technologies, Inc. is headquartered at 505 South Pastoria Ave., Suite 101, Sunnyvale, California 94086, Phone: 408-720-9956, E-Mail: info@syntest.com.
SynTest VirtualScan and TurboBIST-Logic are trademarks of SynTest Technologies, Inc. All other trademarks are property of their respective owners.
Acronyms:
ATPG: Automatic Test Program Generation
BIST: Built-In Self-Test
DFT: Design-for-Test
DFD: Design-for-Debug/Diagnosis
IP: Intellectual Property
TTM: Time-to-Market
Contact:
SynTest Technologies, Inc. Ravi Apte, 408-720-9956 ext. 300
