METHOD FOR RANDOM ACCESS MEMORY DEVICES TESTING Russian patent published in 2012 - IPC G11C29/20 

FIELD: information technology.

SUBSTANCE: method for RAM testing using P-digit pseudo-random number generator based on circular shift register with linear feedback and repetition cycle M. Generator structure is preliminary determined based on inequality system. The method consists in the process where not less than K cycles of testing are carried out in succession in each one of which following procedures are interleaved: procedure of writing test L-digit pseudo-random numbers to all N cells of RAM, and then procedure of reading recorded data from each RAM cell and comparing this data with test pseudo-random numbers. In this process, to generate test L-digit pseudo-random numbers at first new initial non-zero binary P-digit number L digits of which are later used as the first test number is written to pseudo-random number generator, then (N-1) cyclic shifts are carried out sequentially in the shift register with linear feedback and thus N L-digit test numbers are generated. Additionally, selection operation is introduced in which from successively generated pseudo-random numbers only those are selected as test numbers that are spaced apart accurately by L pseudo-random numbers.

EFFECT: providing equal and predicted effectiveness of detection of constant faults and faults due to informational interaction between memory cell in RAM with random structural arrangement.

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