| In recent years,demand for high-capacity memory has grown continually.However,as memory integration density increases incessantly and manufacturing processes become progressively more complex,failure rates have also gradually increased.Consequently,the requirements for memory testing have intensified.The March algorithm,due its high fault coverage rate and linear testing complexity,occupies an important role in memory testing algorithms.However,existing analysis methods for the March algorithm’s fault coverage rate are overly complicated.They couple state requirements with fault sensitization and detection,unable to specify fault primitive levels.Therefore,this thesis proposes a simple March algorithm analysis method.For fault primitives,it generates detection sequences decoupling memory array state from fault sensitization and detection.It converts the March algorithm into a March expression with state changes,namely,memory access state transition descriptors.By matching detection sequences with memory access state transition descriptors,it analyzes the fault coverage rate of the March algorithm for a given fault set and obtains particular fault detection sets.On this basis,optimization and generation methods for the March algorithm have formed,and analysis software for the March algorithm has been designed and implemented.The main research content of this thesis is as follows:(1)The fault set in this thesis primarily includes single-cell faults and double-cell coupling faults in static non-connectivity faults.For different fault primitives of each fault,the detection sequence of each fault primitive is generated combining memory array state and the relative address relationship between attacking and victim cells.The memory access state transition descriptor is defined to describe memory array state during March algorithm progression.When analyzing the fault detection set of the March algorithm,the detection sequence is matched with the March memory access state transition descriptor to obtain the fault detection set of the March algorithm.The fault detection set appears in tabular form in this thesis,defined as a fault detection table recording all fault primitives March can detect.(2)Based on the March analysis method,the March algorithm optimization method has formed.Taking the March C algorithm as an example,it is optimized into new algorithms March C-7 and March C-11.Compared with the classic March C-,it is found the March C-algorithm has the highest fault coverage rate,followed by March C-11,and March C-7 is the worst.(3)Based on the proposed March algorithm analysis method,requirements of the March algorithm analysis software are analyzed from three aspects: function,performance,and human-computer interaction.The MVP architecture is adopted to finish software architecture design,decoupling complex logic,clarifying each module’s responsibilities.The software is designed and implemented according to software layering.Through the research above,this thesis proposes an analysis optimization method for the March algorithm and implements March algorithm analysis software.By analyzing several classic March algorithms,the efficacy and practicality of the March algorithm analysis method are verified. |
