The Study On Test Data Compression Techniques In SoC Test

In the21st century,the integrated circuit industry belongs to SoC.Sincethe semiconductor industry has65nm and smaller technology,the feature sizesof IC constantly shrink.SoC(System on a chip)is a new product of theintegrated circuit,which combine advanced design and technique of IC.It is anultra deep sub-micron chip,which integrate the whole hardware and softwaresystem.Like other engineering,testing is also one of the key technologies ofSoC.Professional testing technology is the main technical means to ensuringcircuit chip high quality.However,as the SoC integration,complexity and speedcontinually improved,the most direct question is the huge amounts of test datafor testing,which lead to SoC test link becomes more complicated.Forexample,auto test machine increasingly unable to meet the need of testconditions,massive data result in testing need longer time and produce morepower consumption.All of these make SoC testing cost increase dramatically.It is obviously that SoC system testing is facing very serious challenges.On thepremise that guarantee the quality of the test,as much as possible to reduce thetest data volume is a meaningful thing,which for the reduction of SoC testtime and cost make a contribution.This is also the goal of this article researchcontent to study.The paper presents and analyzes several classic run-length codingcompression methods in detail.At the same time,this paper summarizes theadvantages and disadvantages of these methods.On the basis of these,the paperputs forward a SoC test data compression method,which based on improvedgrouping FDR.The main contents are as follows:(1)The paper introduces a variety of classic test data coding compressionschemes in detail,which belongs to the BOST(Build Off the Self Test) testtechnology.(2)The paper brings up an independent-bits assignment methods thatbased on the principle of maximum length of run.According to the distribution of adjacent to independent-bits in the original test data, we assign theindependent-bits0or1.This step made good preparation for later work.(3)The paper puts forward a SoC test data compression method,whichbased on improved grouping FDR.After assigning independent-bits,themethod begin to data encoding.By considering the short run and continuous1-runs,which is different between others methods,this method has highercompression ratio.Through the C language code simulating the original test data sets, thesimulation data are imported into the standard sequential circuits ISCAS ’89,the experimental results show that the improvement scheme of test data can beeffectively compressed, and the compression effect is more ideal andfeasibility.