Production-oriented interface testing for PCI-Express by enhanced loop-back technique

Testing PCI-Express (PCI-E) interface at 2.5Gb/s in production is challenging and very expensive. This paper proposes a low-cost test method which could inject data-dependent and bounded random jitters into conventional external loop-back testing configuration, and also could test the jitter tracking capability of the data recovery circuit. This method has been implemented for production testing for a PCI-E interface device, in which the receiver employs a 3times-oversampling data recovery circuit. We analyze the measurement data and study their correlation with the simulation model. We also discuss some important issues for achieving high test accuracy and coverage using loop-back testing