Multi-bit semiconductor memory device allowing efficient testing

Abstract

Data supplied to a particular data input/output terminal is selected and the selected data is subjected to logic change for each memory cell based on mode setting data from a changing mode setting circuit and is simultaneously written into memory cells simultaneously selected in a memory array. After a reading logic changing circuit changes the data of these simultaneously selected memory cells in the same manner as the writing logic changing circuit does, a coincidence/non-coincidence among the logics of these data is determined, and a signal representing a logic in coincidence is output if a coincidence is found. Thus, testing can be achieved at a high speed and accurately, using test data having various patterns, without increasing the number of data input/output terminals used in the testing operation.