Abstract: Systems and methods for analyzing data passing between an SAS/SATA device and a plurality of other devices are presented. A system includes a plurality of physical interfaces configured for passing data between the SAS/SATA device and the other devices. The system also includes a test interface, or test PHY, configured for coupling to the physical interfaces for analysis of the data passing through those physical interfaces. The test PHY may be integrally configured with the SAS/SATA device and may substantially minimize alteration of characteristic impedance caused by external analysis of the data. The system may also include a multiplexer for selectively coupling the PHYs to the test PHY.