基于IEEE标准的IJTAG单层网络测试方法

IJTAG single-layer network test method based on IEEE standards

为利用传统JTAG接口实现对SOC内部大量特定IP测试仪器进行测试控制,提出并创新设计了一种基于传统JTAG接口的可通用、可移植的IEEE 1687标准单层网络测试方法。该方法通过结合IEEE 1149.1标准中TAP控制器结构,提出由改进TAP控制器和改进IR组成IJTAG结构,实现对嵌入式仪器测试访问片内硬件通用接口的设计验证;该测试方法中涵盖了IEEE 1687标准中定义的SIB访问机制和硬件结构,通过外部测试模式选择信号对IR中内置指令进行选择,实现特定SIB打开接入对应测试仪器。该测试方法通过仿真验证了可行性,从而解决了对SOC内部各种测试仪器进行统一测试的控制网络问题,该方法支持常用测试接口标准,同时提出通用操作指令,具有较高的通用性和可移植性。

In order to control the test of a large number of specific IP test instruments in the SOC by the traditional JTAG interface,a universal and portable IEEE 1687 standard single-layer network test method based on the traditional JTAG interface is proposed and innovatively designed. In this method,by combining the structure of the TAP(test access port)controller in the IEEE 1149.1 standard,an IJTAG structure composed of an improved TAP controller and an improved IR(instruction register)is proposed,which realizes the design verification of the hardware general interface in the embedded instrument test access chip.The test method covers the SIB(system information block)access mechanism and hardware structure defined in the IEEE 1687 standard,and selects the built-in instructions in the IR by the external test mode selection signal,so as to enable specific SIB to open and connect to the corresponding test instrument. This method can solve the problem in the control network for uniform testing of various test instruments within the SOC and support common test interface standards. At the same time,it has general operating instructions. Therefore,the proposed method has high versatility and portability. Its feasibility was verified by simulation.