Cost-Effective Test Method for screening out Unexpected Failure in High Speed Serial Interface IPs

In High-Speed Serial Interface (HSSI) IP using AC coupled configuration, due to the AC coupled configuration, it can cause unexpected issues that cannot screen fail chips. That is, external loopback test is not able to reject the fail chip, even if one of the differential positive and negative signals is abnormal status, such as pin floating or open. This paper proposes a cost effective test method can screen unexpected failure without measurement performance degradation assisted by simple circuit modification and additional test sequence.