Research And Realization Of The Board Level Test Method For AD/DA Mixed Signal Chip

The development of LSI tends to be high density,high integration,small size and high performance.Therefore,the classical traditional test methods are increasingly unable to meet the current test requirements,both for digital circuits and digital-analog mixed circuits.Boundary scan technology is to solve the limitation of lsi when using classical test methods.From the birth of boundary scan,it has experienced the formulation and improvement of Std_IEEE1149.1,Std_IEEE1149.4,Std_IEEE1149.5,Std_IEEE1149.6 and Std_IEEE1149.7,and has gradually formed a set of universal testing system.At home and abroad,many units have been devoted to the research of boundary scan technology.At present,however,only digital boundary scan technology is the most mature application.Although there is a complete theoretical system for the mixed circuit boundary scan technology based on IEEE1149.4 standard,but the hardware and software support is still insufficient,mixed circuit testing is difficult to achieve.According to these shortcomings and deficiencies,this paper designed a test system for AD/DA,a representative mixed chip,and completed a board level function test of AD/DA based on the characteristics of digital boundary scan test.Main research contents are as follows:1.Design of the scan chain suitable for AD/DA test.The scheme studied is based on digital boundary scanning test.Through the research on the digital chain,it is found that when the parallel output of ADC and parallel input of DAC are connected with the parallel I/O port of boundary scan device supporting IEEE1149.1 standard,datas can be moved in through TDI and out through TDO,so it can be used as the basic connection method of AD/DA functional test.Then,aiming at the characteristics of AD/DA and problems encountered in the test,an improved chain is proposed,which can satisfy the board level test of AD/DA in most cases.2.A test vector generation algorithm suitable for AD/DA test.The test vectors(or test datas)used for AD/DA test is different from vectors used for interconnection test in digital circuit.It generates a series of voltage test values according to the voltage conversion range of the devices,and achieves functional test by comparing the actual output value with the expected output value.However,due to the different precision of AD/DA devices,the number of test vectors may be very large,so this test vector generation algorithm is proposed to satisfy both completeness and compactedness.The algorithm is based on the digital interconnection test algorithm.3.Design and implement upper computer software for AD/DA test.After chain design and algorithm research,the hardware part is built for verification,and then the upper computer software is combined to form a complete test system.The software can configure the test model,generate the test vectors,retrieve the response datas and analyze them,display the test status and result information on the interface,and export the test report.