Research On Automatic Test System Of Mixed-Signal Circuits Based On Virtual Instrument Technology

The development of science and technology changes rapidly, and the electronicinstrument is widely used in all aspects of the life. With the development ofelectronic chip integration technology, the integration of electronic device becominghigher, the pin being compact in structure, circuit forms becoming more complex, andthe test of the electronic equipment on the core circuit puts forward higherrequirements. The circuit factory test and the use of electronic devices are detecteddirectly related to the life cycle and the production of electronic products, andindirectly affect the market acceptance of the products. Especially with the growingnumber of mixed-signal integrated circuits in the field of aerospace, automobiles,home appliances and other electronic products, traditional bed-of-nails testing andmanual testing methods obviously can not meet the needs of the contemporary hybridcircuit test, and boundary scan technology has come into being. The development ofthe automatic test system to gradually replace the manual testing and continuousimprovement of boundary scan technology provide the basis for the automatic test ofthe hybrid circuits, greatly improving the testability of mixed-signal circuit,shortening the test time and reducing the difficulty of the electronic chip test.Meanwhile, the development of electronic instruments has entered the fourthgeneration-the virtual era of electronic instruments, the use of virtual instrumenttechnology hybrid circuit test is tuned with technological trend.The virtual instrument breaks the traditional instrumental mode, whose hardwareacts as the main instrument and its system is fixed and closed. On contrast, it takes theuse of the efficient, open a flexible software system and provides a graphicalprogramming language, so users can self-customize the instrument interface, and it isconvenient for users to select the hardware module because its adopting modularhardware structure, standard hardware and software platforms to meet the demand for a variety of electronic tests. It is also convenient for the integration of testinginstrument systems. This is the reason why the NI company has been leading the testand measurement industry for nearly30years. With the development of networktechnology, the virtual instrument breaks the space constraints, makes remote testingmore convenient, and lays a solid foundation to build a virtual laboratory for theuniversity at the same time.This paper investigate the mixed circuit automatic test system, boundary-scantechnology and the virtual instrument technology, which is based on VIIS-EM system.VIIS-EM system is an electronic integrated test system which is created by the virtualinstrument laboratory of Jilin University. It works as a blend of signal source, signalmeasurements in time domain and frequency domain, logical analysis, and networkapplications. It provides a common, fast and low-cost reconfigurable test platform forteaching and industrial production.This study mainly includes the IEEE1149.4mixedsignal test bus standards and features. it analysis the content of the new additivemixed-signal test standards in detail, in other words, the analog boundary scan partand the test interface circuit. The boundary-scan technology can be applied to themixed-circuit test system design by VIIS-EM. It realizes the data acquisition module,the hardware of the microprocessor module and the communication module circuitdesign. It can also make hardware integrate into the experimental system bylaboratory independently developed VIIS-EM of bus, and the communication withcomputer by USB. It displays the test data analysis by using LabVIEW to design afriendly interface and test methods. The test verification system can realize thefunction of the mixed-signal circuit test.