Research Of The Test Algorithm For Embedded Memory 3-cell Coupling Fault

With the development of the submicron technology,the integration level of the chip has increased dramatically.Because of the enormous demand of data information storage,embedded memories have occupied more area on SOC(system on chip).As the manufacturing process continues to advance,the more complex structure of the memory makes it generates new fault types,such as 3-cell coupling faults.Memory fault will lead to the increase of the chip escape rate,memory built-in self test(Mbist)has been the mainstream technology for the test of the mass storage memory.So it is significant to set up new fault models and design an effective algorithm for the yield improvetent and lower production cost of the chip.The main works are as follows:1)Based on the analysis of the single-cell faults and coupling faults,I model the additional emerging 3-cell coupling fault,according to the different fault behavior and logic value combination of storage,3-cell coupling faults can be categorized into seven categories,with a total of 1656 kinds of the fault model.2)By analyzing the design ideal of the classical test algorithm,I combine the advantages of the March algorithm and the Checkboard algorithm,a new memory built-in self test algorithm SmarchChk 3C is proposed based on the 1656 kinds of the fault model.The time complexity of this algorithm is 50 N and the fault coverage for3-cell coupling faults is 100%.3)A 2048X32 SRAM has been used for the verification of the algorithm,first of all I build in the memory library file model,I also complete the address generation design and the background data initialization with the EDA tool Tessent Mbist.The algorithm code of the SmarchChk 3C has been imported to EDA tool for simulation,I analysis the key steps of the test algorithm according to the simulation waveform.What's more I complete the verification of validity of the algorithm through the method of fault-injection.The simulation result shows that this algorithm can detect all 3-cell coupling faults and it has the advantage of high fault coverage and short test time.