摘  要随着大规模集成电路、可编程逻辑器件、高速数据信号处理器和计算机技术等的迅猛发展，出现了一类新的测试设备——逻辑分析仪。它是一种分析数字化设备的测试仪器，主要用于分析数字系统的逻辑关系，有效地解决越来越复杂的数字系统的检测和故障诊断问题。逻辑分析仪的出现解决了数字设备、计算机及VLSI超大规模集成电路在研制、生产、检修和文护中的测试问题。
随着电子技术的迅猛发展，微机的广泛应用，基于PC的虚拟仪器也将是测试仪器领域的一大发展趋势。USB(Universal Serial Bus)通用串行总线是一种主流的标准计算机接口。USB接口具有即插即用与热插拔的特性。它可使用户迅速方便地连接PC主机的各种接口设备。基于USB接口的逻辑分析仪充分利用计算机的强大功能，大大突破了传统仪器仪表在数据传送、处理、显示和存储等方面的限制，在性能方面得到了极大的提高。因此研究基于USB接口的虚拟逻辑分析仪具有一定的经济效益和现实意义。38618
本文主要介绍了基于USB接口的虚拟逻辑分析仪的实现原理和过程。采用现场可编程器件FPGA，设计基于USB的虚拟逻辑分析仪，大大简化了外围硬件电路。FPGA(Field-Programmable Gate Array)，即现场可编程门阵列，它是在PAL、GAL、CPLD等可编程器件的基础上进一步发展的产物。它是专用集成电路(ASIC)领域中的一种半定制电路，既解决了定制电路的不足，又克服了原有可编程器件门电路数有限的缺点。采用USB2.0接口提高了PC与外部设备之间的通信速度，传输稳定，使用起来非常方便，并在一定程度上节约了成本。现如今，这种虚拟仪器的强大功能和较大的价格优势使得开发基于PC的虚拟仪器成为一个具有很大发展前景的方向。
毕业论文关键词：逻辑分析仪；USB；FPGA；虚拟仪器
 Abstract
With the rapid development of the LSI， the programmable logic device， the high-speed signal processor， computer technology and so on， a new class of test equipment emerged-logic analyzer. It is a kind of test instrument to analyze the digital devices， is usually used to analyze the logic relationship of the digital system. It can solve the detection and fault diagnosis of the digital system effectively. The emergence of the logic analyzer solves the test of the digital device， computer and VLSI in R&D， production， repair and maintenance.
With the rapid development of the electronics， the widely used of the PC， the virtual instrument based on PC will be a major development trend in the test instrument. USB (Universal Serial Bus) is a mainstream standard computer interface. The USB interface has many features， such as plug and play， hot swap. It allows users to quickly and easily connecting a variety of interface devices of PC. The logic analyzer based on USB makes full use of the computer to break through the limitation of traditional instrumentation in transmission， processing， display and storage， has greatly improved in capability. Therefore， research the logic analyzer based on USB interface is has great economic and practical significance.
This paper describes the principles and processes of the logic analyzer on USB. With the help of the Field-programmable devices-FPGA to design the logic analyzer based on USB， greatly simplifies the peripheral hardware circuit. FPGA-Field-Programmable Gate Array， it is the further development based on PAL， GAL， CPLD and other programmable devices. It is a semi-custom circuit in integrated circuit field. FPGA not only solve the lack of custom circuits， but also has more gates than the old programmable devices. With the USB2.0 interface， the logic analyzer has higher communication speed with PC， transmission stability， very convenient to use and to some extent cost savings. Now， the power of this virtual instrument and greater price advantage makes the development of virtual instrument based on PC become a very promising direction. USB接口逻辑分析仪的软件设计:http://www.751com.cn/tongxin/lunwen_37634.html