现代先进微处理器有非常高的集成度和复杂度，又有寄存器堆、Cache等嵌入式部件，而且芯片管脚数相对较少，必须要有一定的自测试设计和其它的可测试性设计来简化测试代码，提高故障覆盖率。本文简要讨论NRS4000微处理器芯片的以边界扫描测试为主体，以自测试为补充的可测试性设计框架。着重介绍芯片的边界扫描设计和芯片中译码控制器PLA和微程序ＲＯＭ以及采用内嵌RAM结构的指令Cache和寄存器堆的内建自测试设计。仿真结果表明，这些可测试性设计大大缩短了测试代码的长度。-modern microprocessors have a very high degree of integration and complexity, there Register pile, Cache such as embedded components, but Chip few relatively small, There must be the self-test design and testing of other design code to simplify testing, fault coverage. This paper briefly discussed Key words microprocessor chip to the boundary-scan test as the mainstay, Since the test to add to the test design fr a mework. Highlighting the boundary-scan chip design and chip decoder PLA and micro-controller procedures and the use of embedded ROM RA M structure of the instruction cache and register stack of built-in self-test design. The simulation results show that these tests can greatly shorten the design of the test code length.