The Design Of A Test Equipment Of Hard Disk Drive Based On USB Bus

A hard disk drive(HDD) test equipment based on USB bus achieve the SCSI / SATA / IDE to USB protocol conversion and accomplish the reading and writing test of hard disk drive through the USB interface. The articles focuses on the general scheme of the system design, construction hardware circuit, system logic circuit design of three aspects to elaborate the entire design of HDD test module. The main work accomplished in the following aspects:1. The overall design. At first, doing an analysis of the protocol of different hard disks, then doing research in the market investigation, we have selected the chips and completed the build of the system architecture, what’s more, we have also finished a complete circuit schematic design.2. The hardware circuit design. We have mainly introduced the design of the circuit which using in the protocol conversion from USB to SCSI, including the USB interface circuit, the FPGA configuration circuit, the SCSI protocol controller circuit, hard disk interface circuit and so on. We have also analyzed and summarized the problems in the process of drawing the circuit board. Using the mature technology for our USB interface circuit with special USB interface chip, the FAS366 U chip which we have used for our SCSI protocol handler having microprocessor and interface structure, with FPGA as the microprocessor controlling the DMA transfer, the system can works well.3. Digital logic circuit design. The key of the hard disk drive test module is the fast read and write operations of the hard disk. Using Verilog HDL language programming FPGA chip implement an external microprocessor and DMA controller functions, and design asynchronous FIFOs to complete the data transfer. Due to the high internal speed FPGA chip, it not only makes the system’s design more flexible, and better transmission performance, faster response, compared to separate microprocessor, DMA controller, memory chips. In the logic design, the clock circuit module, data transmission control module and the counter module design have be carried on the detailed elaboration, then implement the reading and writing test of hard disk drive.4. Software and hardware on-line debugging. Test results show that the hard drive test module is working properly, PC can favorable control test module to complete the reading and writing tests of HDD, it performance good and reliable.