A test case for 3Gbps serial attached SCSI (SAS)

摘要

The recent deployment of GHz serial interfaces on computer hard drives (HD) includes serial-ATA (SATA), serial-attached-SCSI (SAS), and fiber channel (FC). SOCs and hard drive controller ICs with integrated SATA/SAS links typically have extremely high production volumes, high profit margin pressure, and a low defect rate requirement. On the other hand, constant pursuit for small die size, lower power, fast design cycle, rapid increase in performance specs and price pressure does not normally allow for much design margin. Therefore a comprehensive production test is needed to provide sufficient coverage. However, the test solution needs to be very cost efficient. In this paper, the SAS test case is based on commercially available 3.2Gbps NP3GXS pins (NP cards) on a low cost Agilent 93000 C400 ATE. We demonstrate at-speed test coverage with high throughput for 3Gb/s SATA and SAS production testing. The strengths and limitations for the instrument are also described to provide guidance for future test equipment development.