数据采集器的可测性设计与评估

DFT and Testable Evaluation of Data Collector

针对数模混合系统的快速诊断维修问题,以数据采集器作为对象,研究典型数模混合系统的可测性设计及评估;文章首先介绍了两种先进的可测性设计技术:边界扫描技术和内建自测试技术;以某数据采集系统为对象,阐述其关键性能指标,并依据"分块设计"的方法分析了系统各个测试模块的故障类型和采用的可测试性设计方案;最后,利用TEAMS软件建立了数据采集系统的基于多信号流的模型,经计算及仿真对比了可测性设计前后的测试性设计指标;仿真结果表明,增加可测性设计,可以提高电子系统的故障检测率和隔离率,但要增加测试代价,并在一定程度上降低系统的可靠性。

Based on the problem of fast diagnosis and maintenance of mixed--signal system, the DFT and evaluation of the data collector which is the typical mixed--signal system are researched in this paper. Firstly, two types of advanced DFT technologies： the boundary--scan technology and the BIST technology are introduced. Then, the important capabilities of the data collector are illustrated. The fault types and the design scheme of the test modules in the system are presented. By computing and simulating in TEAMS, the testability design target based on the multi--signal flow model is analyzed. Finally, the results indicate that the DFT could improve the fault--test rate （FIR） and the fault--isolation rate （FIR）, increase the test cost and decrease the system reliability at the same time.