为提高现代军事装备的故障检测能力,运用VC++软件编辑控制界面,设计并制作了一种基于51系列单片机的边界扫描控制器;该控制器由USB转串口电路和单片机构成,结构简单、通用性强且成本低廉;将PC机发送的测试指令或数据进行USB与JTAG协议转换,产生符合IEEE1149.1标准的JTAG总线信号;以EPM7128芯片为测试对象,注入JTAG信号并采集测试响应,实现了对基于测试芯片硬件电路的故障检测;测试结果表明:设计的边界扫描控制器可实现对单芯片和芯片级联的边界扫描状态的控制,能避开可编程芯片的内部逻辑程序控制,完成对可编程芯片及其外围电路的故障检测。
A boundary scan controller based on 51 -- series MCU, with a control interface programed by Microsoft Visual C++ software, is de- signed and manufactured in order to improve the fault detection ability of modern military equipment. The controller, which is made up of an USB to serial interface circuit and MCU, has the merits of simple structure, high universality and low cost. The test Instructions or data from computer arc transformed to JTAG bus signals meeting the standard of IEEE1149. 1 according to USB and JTAG protocol conversion. The JTAG signals are injected in EPM7128 chips as test object, then collect test response and implement the fault detection of hardware circuit based on test chips. The test results show that the design of boundary scan controller can control the boundary scan state of the single chip and chip cascades, and complete fault detection on the chip and its peripheral circuit without control of the internal logic of the programmable logic chip program.